A progressive form of dementia characterized by the global loss of language abilities and initial preservation of other cognitive functions. Fluent and nonfluent subtypes have been described. Eventually a pattern of global cognitive dysfunction, similar to ALZHEIMER DISEASE, emerges. Pathologically, there are no Alzheimer or PICK DISEASE like changes, however, spongiform changes of cortical layers II and III are present in the TEMPORAL LOBE and FRONTAL LOBE. (From Brain 1998 Jan;121(Pt 1):115-26)
A cognitive disorder marked by an impaired ability to comprehend or express language in its written or spoken form. This condition is caused by diseases which affect the language areas of the dominant hemisphere. Clinical features are used to classify the various subtypes of this condition. General categories include receptive, expressive, and mixed forms of aphasia.
A form of frontotemporal lobar degeneration and a progressive form of dementia characterized by motor speech impairment and AGRAMMATISM, with relative sparing of single word comprehension and semantic memory.
A form of multiple sclerosis characterized by a progressive deterioration in neurologic function which is in contrast to the more typical relapsing remitting form. If the clinical course is free of distinct remissions, it is referred to as primary progressive multiple sclerosis. When the progressive decline is punctuated by acute exacerbations, it is referred to as progressive relapsing multiple sclerosis. The term secondary progressive multiple sclerosis is used when relapsing remitting multiple sclerosis evolves into the chronic progressive form. (From Ann Neurol 1994;36 Suppl:S73-S79; Adams et al., Principles of Neurology, 6th ed, pp903-914)
A language dysfunction characterized by the inability to name people and objects that are correctly perceived. The individual is able to describe the object in question, but cannot provide the name. This condition is associated with lesions of the dominant hemisphere involving the language areas, in particular the TEMPORAL LOBE. (From Adams et al., Principles of Neurology, 6th ed, p484)
An aphasia characterized by impairment of expressive LANGUAGE (speech, writing, signs) and relative preservation of receptive language abilities (i.e., comprehension). This condition is caused by lesions of the motor association cortex in the FRONTAL LOBE (BROCA AREA and adjacent cortical and white matter regions).
Tests designed to assess language behavior and abilities. They include tests of vocabulary, comprehension, grammar and functional use of language, e.g., Development Sentence Scoring, Receptive-Expressive Emergent Language Scale, Parsons Language Sample, Utah Test of Language Development, Michigan Language Inventory and Verbal Language Development Scale, Illinois Test of Psycholinguistic Abilities, Northwestern Syntax Screening Test, Peabody Picture Vocabulary Test, Ammons Full-Range Picture Vocabulary Test, and Assessment of Children's Language Comprehension.
Loss or impairment of the ability to write (letters, syllables, words, or phrases) due to an injury to a specific cerebral area or occasionally due to emotional factors. This condition rarely occurs in isolation, and often accompanies APHASIA. (From Adams et al., Principles of Neurology, 6th ed, p485; APA, Thesaurus of Psychological Index Terms, 1994)
Decrease in the size of a cell, tissue, organ, or multiple organs, associated with a variety of pathological conditions such as abnormal cellular changes, ischemia, malnutrition, or hormonal changes.
The most common clinical variant of MULTIPLE SCLEROSIS, characterized by recurrent acute exacerbations of neurologic dysfunction followed by partial or complete recovery. Common clinical manifestations include loss of visual (see OPTIC NEURITIS), motor, sensory, or bladder function. Acute episodes of demyelination may occur at any site in the central nervous system, and commonly involve the optic nerves, spinal cord, brain stem, and cerebellum. (Adams et al., Principles of Neurology, 6th ed, pp903-914)
Hormones produced by the placenta include CHORIONIC GONADOTROPIN, and PLACENTAL LACTOGEN as well as steroids (ESTROGENS; PROGESTERONE), and neuropeptide hormones similar to those found in the hypothalamus (HYPOTHALAMIC HORMONES).
Communication through a system of conventional vocal symbols.
A group of cognitive disorders characterized by the inability to perform previously learned skills that cannot be attributed to deficits of motor or sensory function. The two major subtypes of this condition are ideomotor (see APRAXIA, IDEOMOTOR) and ideational apraxia, which refers to loss of the ability to mentally formulate the processes involved with performing an action. For example, dressing apraxia may result from an inability to mentally formulate the act of placing clothes on the body. Apraxias are generally associated with lesions of the dominant PARIETAL LOBE and supramarginal gyrus. (From Adams et al., Principles of Neurology, 6th ed, pp56-7)
An autoimmune disorder mainly affecting young adults and characterized by destruction of myelin in the central nervous system. Pathologic findings include multiple sharply demarcated areas of demyelination throughout the white matter of the central nervous system. Clinical manifestations include visual loss, extra-ocular movement disorders, paresthesias, loss of sensation, weakness, dysarthria, spasticity, ataxia, and bladder dysfunction. The usual pattern is one of recurrent attacks followed by partial recovery (see MULTIPLE SCLEROSIS, RELAPSING-REMITTING), but acute fulminating and chronic progressive forms (see MULTIPLE SCLEROSIS, CHRONIC PROGRESSIVE) also occur. (Adams et al., Principles of Neurology, 6th ed, p903)
Tests designed to assess neurological function associated with certain behaviors. They are used in diagnosing brain dysfunction or damage and central nervous system disorders or injury.
Treatment for individuals with speech defects and disorders that involves counseling and use of various exercises and aids to help the development of new speech habits.
The relationships between symbols and their meanings.
A type of fluent aphasia characterized by an impaired ability to repeat one and two word phrases, despite retained comprehension. This condition is associated with dominant hemisphere lesions involving the arcuate fasciculus (a white matter projection between Broca's and Wernicke's areas) and adjacent structures. Like patients with Wernicke aphasia (APHASIA, WERNICKE), patients with conduction aphasia are fluent but commit paraphasic errors during attempts at written and oral forms of communication. (From Adams et al., Principles of Neurology, 6th ed, p482; Brain & Bannister, Clinical Neurology, 7th ed, p142; Kandel et al., Principles of Neural Science, 3d ed, p848)
The most common clinical form of FRONTOTEMPORAL LOBAR DEGENERATION, this dementia presents with personality and behavioral changes often associated with disinhibition, apathy, and lack of insight.
Conditions characterized by deficiencies of comprehension or expression of written and spoken forms of language. These include acquired and developmental disorders.
Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.
Acquired or developmental conditions marked by an impaired ability to comprehend or generate spoken forms of language.
Impairment in the comprehension of speech and meaning of words, both spoken and written, and of the meanings conveyed by their grammatical relationships in sentences. It is caused by lesions that primarily affect Wernicke's area, which lies in the posterior perisylvian region of the temporal lobe of the dominant hemisphere. (From Brain & Bannister, Clinical Neurology, 7th ed, p141; Kandel et al., Principles of Neural Science, 3d ed, p846)
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
Heterogeneous group of neurodegenerative disorders characterized by frontal and temporal lobe atrophy associated with neuronal loss, gliosis, and dementia. Patients exhibit progressive changes in social, behavioral, and/or language function. Multiple subtypes or forms are recognized based on presence or absence of TAU PROTEIN inclusions. FTLD includes three clinical syndromes: FRONTOTEMPORAL DEMENTIA, semantic dementia, and PRIMARY PROGRESSIVE NONFLUENT APHASIA.
A verbal or nonverbal means of communicating ideas or feelings.
A subclass of sodium channel blockers that are specific for ACID-SENSING SODIUM CHANNELS.
Lower lateral part of the cerebral hemisphere responsible for auditory, olfactory, and semantic processing. It is located inferior to the lateral fissure and anterior to the OCCIPITAL LOBE.
A rare form of DEMENTIA that is sometimes familial. Clinical features include APHASIA; APRAXIA; CONFUSION; ANOMIA; memory loss; and personality deterioration. This pattern is consistent with the pathologic findings of circumscribed atrophy of the poles of the FRONTAL LOBE and TEMPORAL LOBE. Neuronal loss is maximal in the HIPPOCAMPUS, entorhinal cortex, and AMYGDALA. Some ballooned cortical neurons contain argentophylic (Pick) bodies. (From Brain Pathol 1998 Apr;8(2):339-54; Adams et al., Principles of Neurology, 6th ed, pp1057-9)
Rehabilitation of persons with language disorders or training of children with language development disorders.
The worsening of a disease over time. This concept is most often used for chronic and incurable diseases where the stage of the disease is an important determinant of therapy and prognosis.
Non-invasive methods of visualizing the CENTRAL NERVOUS SYSTEM, especially the brain, by various imaging modalities.
An acquired organic mental disorder with loss of intellectual abilities of sufficient severity to interfere with social or occupational functioning. The dysfunction is multifaceted and involves memory, behavior, personality, judgment, attention, spatial relations, language, abstract thought, and other executive functions. The intellectual decline is usually progressive, and initially spares the level of consciousness.
Involuntary ("parrot-like"), meaningless repetition of a recently heard word, phrase, or song. This condition may be associated with transcortical APHASIA; SCHIZOPHRENIA; or other disorders. (From Adams et al., Principles of Neurology, 6th ed, p485)
Includes both producing and responding to words, either written or spoken.
The use of diffusion ANISOTROPY data from diffusion magnetic resonance imaging results to construct images based on the direction of the faster diffusing molecules.
The act or fact of grasping the meaning, nature, or importance of; understanding. (American Heritage Dictionary, 4th ed) Includes understanding by a patient or research subject of information disclosed orally or in writing.
The part of the cerebral hemisphere anterior to the central sulcus, and anterior and superior to the lateral sulcus.
Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.
A degenerative disease of the BRAIN characterized by the insidious onset of DEMENTIA. Impairment of MEMORY, judgment, attention span, and problem solving skills are followed by severe APRAXIAS and a global loss of cognitive abilities. The condition primarily occurs after age 60, and is marked pathologically by severe cortical atrophy and the triad of SENILE PLAQUES; NEUROFIBRILLARY TANGLES; and NEUROPIL THREADS. (From Adams et al., Principles of Neurology, 6th ed, pp1049-57)
A spontaneous diminution or abatement of a disease over time, without formal treatment.
Standardized clinical interview used to assess current psychopathology by scaling patient responses to the questions.
Behavioral manifestations of cerebral dominance in which there is preferential use and superior functioning of either the left or the right side, as in the preferred use of the right hand or right foot.
A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.
Assessment of sensory and motor responses and reflexes that is used to determine impairment of the nervous system.
The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulchi. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.
Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.
Determination of the degree of a physical, mental, or emotional handicap. The diagnosis is applied to legal qualification for benefits and income under disability insurance and to eligibility for Social Security and workmen's compensation benefits.
Disturbances in mental processes related to learning, thinking, reasoning, and judgment.
Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.
Aniline compounds, also known as aromatic amines, are organic chemicals derived from aniline (aminobenzene), characterized by the substitution of hydrogen atoms in the benzene ring with amino groups (-NH2).
The age, developmental stage, or period of life at which a disease or the initial symptoms or manifestations of a disease appear in an individual.
A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.
Methods developed to aid in the interpretation of ultrasound, radiographic images, etc., for diagnosis of disease.
An imaging technique using compounds labelled with short-lived positron-emitting radionuclides (such as carbon-11, nitrogen-13, oxygen-15 and fluorine-18) to measure cell metabolism. It has been useful in study of soft tissues such as CANCER; CARDIOVASCULAR SYSTEM; and brain. SINGLE-PHOTON EMISSION-COMPUTED TOMOGRAPHY is closely related to positron emission tomography, but uses isotopes with longer half-lives and resolution is lower.
A receptive visual aphasia characterized by the loss of a previously possessed ability to comprehend the meaning or significance of handwritten words, despite intact vision. This condition may be associated with posterior cerebral artery infarction (INFARCTION, POSTERIOR CEREBRAL ARTERY) and other BRAIN DISEASES.
A class of nerve fibers as defined by their structure, specifically the nerve sheath arrangement. The AXONS of the myelinated nerve fibers are completely encased in a MYELIN SHEATH. They are fibers of relatively large and varied diameters. Their NEURAL CONDUCTION rates are faster than those of the unmyelinated nerve fibers (NERVE FIBERS, UNMYELINATED). Myelinated nerve fibers are present in somatic and autonomic nerves.
Measurement of parameters of the speech product such as vocal tone, loudness, pitch, voice quality, articulation, resonance, phonation, phonetic structure and prosody.
The science of language, including phonetics, phonology, morphology, syntax, semantics, pragmatics, and historical linguistics. (Random House Unabridged Dictionary, 2d ed)
Loss of functional activity and trophic degeneration of nerve axons and their terminal arborizations following the destruction of their cells of origin or interruption of their continuity with these cells. The pathology is characteristic of neurodegenerative diseases. Often the process of nerve degeneration is studied in research on neuroanatomical localization and correlation of the neurophysiology of neural pathways.
A class of statistical methods applicable to a large set of probability distributions used to test for correlation, location, independence, etc. In most nonparametric statistical tests, the original scores or observations are replaced by another variable containing less information. An important class of nonparametric tests employs the ordinal properties of the data. Another class of tests uses information about whether an observation is above or below some fixed value such as the median, and a third class is based on the frequency of the occurrence of runs in the data. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1284; Corsini, Concise Encyclopedia of Psychology, 1987, p764-5)
A group of pathological conditions characterized by sudden, non-convulsive loss of neurological function due to BRAIN ISCHEMIA or INTRACRANIAL HEMORRHAGES. Stroke is classified by the type of tissue NECROSIS, such as the anatomic location, vasculature involved, etiology, age of the affected individual, and hemorrhagic vs. non-hemorrhagic nature. (From Adams et al., Principles of Neurology, 6th ed, pp777-810)
A meshlike structure composed of interconnecting nerve cells that are separated at the synaptic junction or joined to one another by cytoplasmic processes. In invertebrates, for example, the nerve net allows nerve impulses to spread over a wide area of the net because synapses can pass information in any direction.
A degenerative disease of the central nervous system characterized by balance difficulties; OCULAR MOTILITY DISORDERS (supranuclear ophthalmoplegia); DYSARTHRIA; swallowing difficulties; and axial DYSTONIA. Onset is usually in the fifth decade and disease progression occurs over several years. Pathologic findings include neurofibrillary degeneration and neuronal loss in the dorsal MESENCEPHALON; SUBTHALAMIC NUCLEUS; RED NUCLEUS; pallidum; dentate nucleus; and vestibular nuclei. (From Adams et al., Principles of Neurology, 6th ed, pp1076-7)
The return of a sign, symptom, or disease after a remission.
The coordination of a sensory or ideational (cognitive) process and a motor activity.
Personal names, given or surname, as cultural characteristics, as ethnological or religious patterns, as indications of the geographic distribution of families and inbreeding, etc. Analysis of isonymy, the quality of having the same or similar names, is useful in the study of population genetics. NAMES is used also for the history of names or name changes of corporate bodies, such as medical societies, universities, hospitals, government agencies, etc.
Tomography using x-ray transmission and a computer algorithm to reconstruct the image.

Primary progressive aphasia : a case report. (1/119)

Primary progressive aphasia is due to focal left perisylvian degeneration and manifests with progressive decline in language function for two or more years. There is preservation of cognitive functions and activities of daily living continue to be normal. We report a case of progressive aphasia in a 65 year old lady.  (+info)

Atypical and typical presentations of Alzheimer's disease: a clinical, neuropsychological, neuroimaging and pathological study of 13 cases. (2/119)

There has been increasing awareness that some slowly progressive focal cortical syndromes can be the presenting features of Alzheimer's disease, but pathological evidence has been sparse. This clinico-pathological series presents our experience with pathologically proven atypical as well as typical Alzheimer's disease presentations. We report and compare four patterns of presentation: a typical pattern with initial amnesic syndrome (n = 4 cases), progressive visual dysfunction (n = 1), progressive biparietal syndrome (n = 2) and progressive aphasia (n = 6). The aphasic presentations include both fluent and non-fluent aphasic syndromes. The neuropsychological profiles and neuroimaging clearly reflect the presenting clinical features, and show a close relationship to the distribution of pathology in these cases. Of note was the sparing of medial temporal structures (hippocampus and/or entorhinal cortex) in several aphasic cases and the severe occipito-parietal involvement in those with prominent visuospatial disorders at presentation. Our data demonstrate the wide spectrum of Alzheimer's disease presentations. The recognition of atypical presentations of Alzheimer's disease is important when attempting to make an early accurate pre-morbid diagnosis of neurodegenerative disease.  (+info)

Frontotemporal decreases in rCBF correlate with degree of dysnomia in primary progressive aphasia. (3/119)

Primary progressive aphasia (PPA) is an uncommon degenerative dementia characterized by gradual impairment of language function with initial sparing of the memory domain. Using semiquantitative 99mTc-hexamethyl propyleneamine oxime (HMPAO) brain SPECT as a measure of regional cerebral blood flow (rCBF), we investigated the relationship between reduced 99mTc-HMPAO uptake and the severity of dysnomia in PPA. METHODS: Seven right-handed patients with PPA had their dysnomia assessed by the Boston Naming Test (BNT), a subtest of the Boston Diagnostic Aphasia Examination. Neuroimaging studies, including 99mTc-HMPAO brain SPECT, CT, and MRI, were performed. Correlational analysis between reduced rCBF and BNT was performed. RESULTS: Brain SPECT showed a reduction in 99mTc-HMPAO uptake involving the frontal and temporal lobes in all 7 patients. CT and MRI showed mild to moderate cerebral atrophy in 4 patients. Low scores on the BNT correlated with low frontotemporal 99mTc-HMPAO (Spearman r = 0.97, P = 0.004) in the 5 patients with left-hemisphere involvement. CONCLUSION: Decreased rCBF to the frontotemporal region characterized the cerebral abnormalities associated with PPA. The finding of focal rCBF abnormalities in the right hemisphere of 2 right-handed women corroborates that PPA symptoms may arise from a "non-left-dominant"-hemisphere degenerative process. Our results support the usefulness of rCBF SPECT imaging as a diagnostic aid in PPA.  (+info)

The role of conceptual knowledge in object use evidence from semantic dementia. (4/119)

It has been reported that patients with semantic dementia function well in everyday life and sometimes show striking preservation of the ability to use objects, even those specific objects for which the patient has degraded conceptual information. To explore this phenomenon in nine cases of semantic dementia, we designed a set of semantic tests regarding 20 everyday objects and compared performance on these with the patients' ability to demonstrate the correct use of the same items. We also administered a test of mechanical problem solving utilizing novel tools, on which the patients had completely normal ability. All but the mildest affected patient showed significant deficits of naming and on the visually based semantic matching tasks. Object use was markedly impaired and, most importantly, correlated strongly with naming and semantic knowledge. In a small number of instances, there was appropriate use of an object for which the patient's knowledge on the semantic matching tasks was no better than chance; but this typically applied to objects with a rather obvious relationship between appearance and use, or was achieved by trial and error. The results suggest that object use is heavily dependent upon object-specific conceptual knowledge, supplemented to some degree by a combination of visual affordances and mechanical problem solving.  (+info)

Primary progressive aphasia: analisys of 16 cases. (5/119)

Primary progressive aphasia (PPA) is an intriguing syndrome, showing some peculiar aspects that differentiate it from classical aphasic pictures caused by focal cerebral lesions or dementia. The slow and progressive deterioration of language occurring in these cases provides an interesting model to better understand the mechanisms involved in the linguistic process. We describe clinical and neuroimaging aspects found in 16 cases of PPA. Our patients underwent language and neuropsychological evaluation, magnetic resonance imaging (MRI) and single photon emission computerized tomography (SPECT). We observed a clear distinction in oral expression patterns; patients were classified as fluent and nonfluent. Anomia was the earliest and most evident symptom in both groups. Neuroimaging pointed to SPECT as a valuable instrument in guiding the differential diagnosis, as well as in making useful clinical and anatomical correlations. This report and a comparison to literature are an attempt to contribute to a better understanding of PPA.  (+info)

Evidence of bilateral temporal lobe involvement in primary progressive aphasia: a SPECT study. (6/119)

Primary progressive aphasia (PPA) is rare. Only limited series have been reported with SPECT or PET. Moreover, in the majority of studies, the left-to-right asymmetry ratio was used, leading to difficulties in right hemisphere analyzes. METHODS: Twenty-nine patients with clinical criteria of PPA (Mesulam and Weintraub) were included and compared with 12 control subjects. Complete language examination was performed in all patients. SPECT was performed on a double-head gamma camera after intravenous injection of hexamethylpropyleneamine oxime (22 patients and 12 control subjects) or ethylcysteinate dimer (7 patients). Nineteen regions of interest (ROIs) were drawn on each hemisphere in all patients using the Talairach atlas. The perfusion index (PI = cortex-to-cerebellum ratio) was calculated for each ROI. Atrophy was quantified on MRI by consensus of 3 observers in 16 cortical ROIs. ANOVAs were used to compare the PI between (a). patients and control subjects, (b). patients with (n = 15) or without (n = 14) lexicosemantic abnormalities (LS+ vs. LS-) and patients with (n = 19) or without (n = 10) arthric disorders (A+ vs. A-), and (c). patients with or without atrophy. RESULTS: In the 29 patients, the PI was significantly lower in the left temporopolar, left lateral temporal, left Wernicke, left parietal, and right lateral temporal cortex when compared with control subjects (P < 0.001). In LS+ patients versus control subjects, the PI significantly decreased in the left temporal cortex (lateral temporal; medial temporal; temporopolar; Wernicke), left Broca, left parietal, and right lateral temporal cortex (P < 0.001). In addition, LS+ versus LS- comparison showed a significant decrease in the left lateral, left medial temporal, and left Broca cortex (P < 0.001). In comparison with control subjects, the PI was not significantly different in A+ patients, whereas in A- patients the PI was significantly decreased in the left and right lateral temporal cortex, left Wernicke, and left parietal cortex. Moreover, the PI significantly decreased in the left lateral temporal region in A+ patients compared with A- patients. Finally, in patients without atrophy, the PI significantly decreased in the right and left lateral temporal cortex and the left parietal cortex (P < 0.01). CONCLUSION: Our study demonstrates that right-handed patients with PPA present a decreased perfusion in the bilateral temporal cortex. Moreover, in these regions, morphologic abnormalities are preceded by perfusion abnormalities. Finally, our results show that large left temporal dysfunction occurs in patients with LS disorders.  (+info)

Progressive non-fluent aphasia is associated with hypometabolism centred on the left anterior insula. (7/119)

Progressive non-fluent aphasia (PNFA) is a syndrome in which patients lose the ability to communicate fluently in the context of relative preservation of single word comprehension and non-linguistic cognitive abilities. Neuroimaging in case studies with PNFA has failed to identify a consistent neural substrate for the language disorder. In this study of a group of patients (n=10) whose presenting complaint was progressive dysfluency, resting cerebral metabolism was measured using [18F]fluorodeoxyglucose-PET and analysed with the technique of statistical parametric mapping (SPM). Regional atrophy was assessed with voxel-based morphometry (VBM). Seven patients had a 'pure' PNFA syndrome, while the remaining three had additional features of a more pervasive dementia. Compared with controls, the patients showed hypometabolism in several regions that, most notably, included the left anterior insula/frontal opercular region. The VBM analysis revealed only one small area of atrophy in the left peri-Sylvian region. Analysis of the pure PNFA cases (n=7) relative to controls yielded qualitatively similar results to those of the whole group, suggesting that these cases were also at risk of a more generalized dementia, a finding borne out in subsequent follow-up of two cases to date. The PNFA group was then compared with a group with Alzheimer's disease (n=10) whose clinical profile did not include non-fluent aphasic features. In this analysis, the only persisting hypometabolic region was that centred over the left anterior insula. VBM did not identify any regional differences in atrophy between PNFA and Alzheimer's disease. In the light of current theories of fluent language production, the findings offer anatomical evidence that the breakdown in fluency is due to a motor articulatory planning deficit (speech apraxia) combined with a variable degree of agrammatism.  (+info)

Cognition and anatomy in three variants of primary progressive aphasia. (8/119)

We performed a comprehensive cognitive, neuroimaging, and genetic study of 31 patients with primary progressive aphasia (PPA), a decline in language functions that remains isolated for at least 2 years. Detailed speech and language evaluation was used to identify three different clinical variants: nonfluent progressive aphasia (NFPA; n = 11), semantic dementia (SD; n = 10), and a third variant termed logopenic progressive aphasia (LPA; n = 10). Voxel-based morphometry (VBM) on MRIs showed that, when all 31 PPA patients were analyzed together, the left perisylvian region and the anterior temporal lobes were atrophied. However, when each clinical variant was considered separately, distinctive patterns emerged: (1) NFPA, characterized by apraxia of speech and deficits in processing complex syntax, was associated with left inferior frontal and insular atrophy; (2) SD, characterized by fluent speech and semantic memory deficits, was associated with anterior temporal damage; and (3) LPA, characterized by slow speech and impaired syntactic comprehension and naming, showed atrophy in the left posterior temporal cortex and inferior parietal lobule. Apolipoprotein E epsilon4 haplotype frequency was 20% in NFPA, 0% in SD, and 67% in LPA. Cognitive, genetic, and anatomical features indicate that different PPA clinical variants may correspond to different underlying pathological processes.  (+info)

Primary Progressive Aphasia (PPA) is a neurological disorder characterized by progressive loss of language capabilities, while other cognitive abilities remain preserved. It is a type of dementia that primarily affects speech and language. Unlike other forms of aphasia that result from stroke or head injury, PPA is degenerative and gets worse over time.

There are three main types of PPA:

1. Semantic Variant PPA (svPPA): This type is characterized by difficulty in understanding words and objects, despite having no trouble with the mechanics of speech or writing. Over time, people with svPPA may lose their ability to understand spoken or written language, as well as to recognize objects and faces.

2. Nonfluent/Agrammatic Variant PPA (nfvPPA): This type is characterized by difficulty with speaking and writing, including producing grammatical sentences and articulating words. People with nfvPPA may also have problems with understanding spoken language, particularly when it comes to complex sentences or ambiguous phrases.

3. Logopenic Variant PPA (lvPPA): This type is characterized by difficulty with word-finding and sentence repetition, while speech remains fluent. People with lvPPA may also have problems with understanding spoken language, particularly when it comes to complex sentences or ambiguous phrases.

The exact cause of PPA is not known, but it is believed to be related to degeneration of specific areas of the brain involved in language processing, such as Broca's area and Wernicke's area. There is currently no cure for PPA, but speech and language therapy can help to slow down the progression of the disorder and improve communication skills.

Aphasia is a medical condition that affects a person's ability to communicate. It is caused by damage to the language areas of the brain, most commonly as a result of a stroke or head injury. Aphasia can affect both spoken and written language, making it difficult for individuals to express their thoughts, understand speech, read, or write.

There are several types of aphasia, including:

1. Expressive aphasia (also called Broca's aphasia): This type of aphasia affects a person's ability to speak and write clearly. Individuals with expressive aphasia know what they want to say but have difficulty forming the words or sentences to communicate their thoughts.
2. Receptive aphasia (also called Wernicke's aphasia): This type of aphasia affects a person's ability to understand spoken or written language. Individuals with receptive aphasia may struggle to follow conversations, comprehend written texts, or make sense of the words they hear or read.
3. Global aphasia: This is the most severe form of aphasia and results from extensive damage to the language areas of the brain. People with global aphasia have significant impairments in both their ability to express themselves and understand language.
4. Anomic aphasia: This type of aphasia affects a person's ability to recall the names of objects, people, or places. Individuals with anomic aphasia can speak in complete sentences but often struggle to find the right words to convey their thoughts.

Treatment for aphasia typically involves speech and language therapy, which aims to help individuals regain as much communication ability as possible. The success of treatment depends on various factors, such as the severity and location of the brain injury, the individual's motivation and effort, and the availability of support from family members and caregivers.

Primary Progressive Nonfluent Aphasia (PPNA) is a rare type of dementia that primarily affects language abilities. According to the National Aphasia Association, it is characterized by progressive difficulty with speaking and writing, while comprehension of single words and object knowledge remains relatively intact. The "nonfluent" descriptor refers to the hesitant, effortful, and halting speech pattern observed in individuals with this condition.

The Medical Subject Headings (MeSH) term provided by the National Library of Medicine defines PPNA as:

"A progressive aphasia characterized by agrammatism and/or anomia with relatively preserved single word comprehension and object knowledge. This condition often, but not always, begins between the sixth and seventh decades of life. As the disorder progresses, it may be accompanied by ideomotor apraxia, alien hand syndrome, and elements of corticobasal degeneration."

It is important to note that PPNA is a clinical diagnosis, and there are currently no established biomarkers or imaging techniques to definitively diagnose this condition. The underlying neuropathology may vary between individuals with PPNA, but the most common causes include frontotemporal lobar degeneration (FTLD) and corticobasal degeneration (CBD).

Multiple Sclerosis (MS), Chronic Progressive is a form of Multiple Sclerosis, a chronic autoimmune disease that affects the central nervous system (CNS). In this form, the disease follows a steady progression with no distinct relapses or remissions. The symptoms worsen over time, leading to a decline in physical functioning and increased disability.

The term "chronic progressive" is used to describe the course of the disease, which is characterized by a continuous worsening of neurological functions from the onset, or after an initial relapsing-remitting phase. There are two types of chronic progressive MS: primary and secondary.

1. Primary Chronic Progressive MS (PCP): This form of MS shows a steady progression of symptoms from the beginning, with no distinct remissions or relapses. The disability accumulates gradually over time, and the person may experience varying degrees of physical and cognitive impairment.

2. Secondary Chronic Progressive MS (SCP): In this form, an individual initially has a relapsing-remitting course of MS (RRMS), characterized by unpredictable relapses followed by periods of partial or complete recovery (remissions). However, after some time, the disease transitions to a steady progression of symptoms and disability, even without distinct relapses. This is known as secondary chronic progressive MS.

The exact cause of Multiple Sclerosis remains unknown; however, it is believed to be influenced by genetic, environmental, and immunological factors. The disease involves the immune system attacking the myelin sheath, a protective covering surrounding nerve fibers in the CNS. This results in lesions or scars (scleroses) that disrupt communication between the brain, spinal cord, and other parts of the body, leading to various physical, cognitive, and sensory symptoms.

Management of Chronic Progressive MS typically involves a multidisciplinary approach, focusing on symptom management, rehabilitation, and maintaining quality of life. Currently, there are no approved disease-modifying therapies specifically for chronic progressive MS; however, some medications used to treat relapsing-remitting MS may help slow the progression of disability in certain individuals with secondary chronic progressive MS.

Anomia is a language disorder that affects a person's ability to name objects, places, or people. It is often caused by damage to the brain, such as from a stroke, brain injury, or neurological condition. In anomia, a person has difficulty retrieving words from their memory, and may substitute similar-sounding words, describe the object instead of naming it, or be unable to come up with a name at all. Anomia can range from mild to severe and can significantly impact a person's ability to communicate effectively.

Broca's aphasia, also known as expressive aphasia or nonfluent aphasia, is a type of language disorder that results from damage to the brain's Broca's area, which is located in the frontal lobe of the dominant hemisphere (usually the left).

Individuals with Broca's aphasia have difficulty producing spoken or written language. They often know what they want to say but have trouble getting the words out, resulting in short and grammatically simplified sentences. Speech may be slow, laborious, and agrammatic, with limited vocabulary and poor sentence structure. Comprehension of language is typically less affected than expression, although individuals with Broca's aphasia may have difficulty understanding complex grammatical structures or following rapid speech.

It's important to note that the severity and specific symptoms of Broca's aphasia can vary depending on the extent and location of the brain damage. Rehabilitation and therapy can help improve language skills in individuals with Broca's aphasia, although recovery may be slow and limited.

A language test is not a medical term per se, but it is commonly used in the field of speech-language pathology, which is a medical discipline. A language test, in this context, refers to an assessment tool used by speech-language pathologists to evaluate an individual's language abilities. These tests typically measure various aspects of language, including vocabulary, grammar, syntax, semantics, and pragmatics.

Language tests can be standardized or non-standardized and may be administered individually or in a group setting. The results of these tests help speech-language pathologists diagnose language disorders, develop treatment plans, and monitor progress over time. It is important to note that language testing should be conducted by a qualified professional who has experience in administering and interpreting language assessments.

Agraphia is a neurological disorder that affects the ability to write, either by hand or through mechanical means like typing. It is often caused by damage to specific areas of the brain involved in language and writing skills, such as the left parietal lobe. Agraphia can manifest as difficulty with spelling, forming letters or words, organizing thoughts on paper, or expressing ideas in writing. Depending on the severity and location of the brain injury, agraphia may occur in isolation or alongside other language or cognitive impairments.

Atrophy is a medical term that refers to the decrease in size and wasting of an organ or tissue due to the disappearance of cells, shrinkage of cells, or decreased number of cells. This process can be caused by various factors such as disuse, aging, degeneration, injury, or disease.

For example, if a muscle is immobilized for an extended period, it may undergo atrophy due to lack of use. Similarly, certain medical conditions like diabetes, cancer, and heart failure can lead to the wasting away of various tissues and organs in the body.

Atrophy can also occur as a result of natural aging processes, leading to decreased muscle mass and strength in older adults. In general, atrophy is characterized by a decrease in the volume or weight of an organ or tissue, which can have significant impacts on its function and overall health.

Relapsing-remitting multiple sclerosis (RRMS) is a type of multiple sclerosis (MS), which is a chronic autoimmune disease that affects the central nervous system (CNS). In RRMS, the immune system attacks the protective covering of nerve fibers (myelin sheath) in the CNS, leading to the formation of lesions or scars (scleroses). These attacks result in episodes of new or worsening symptoms, known as relapses or exacerbations.

The distinguishing feature of RRMS is that these relapses are followed by periods of partial or complete recovery (remissions), during which symptoms may improve, stabilize, or even disappear temporarily. The duration and severity of relapses and remissions can vary significantly among individuals with RRMS. Over time, the accumulation of damage to the nervous system can lead to progressive disability.

Approximately 85% of people with MS are initially diagnosed with the relapsing-remitting form. With appropriate treatment and management, many people with RRMS can effectively manage their symptoms and maintain a good quality of life for several years.

Placental hormones are a type of hormones that are produced by the placenta, an organ that develops in the uterus during pregnancy. These hormones play a crucial role in maintaining and supporting a healthy pregnancy. Some of the key placental hormones include:

1. Human Chorionic Gonadotropin (hCG): This hormone is produced after implantation and is detected in the urine or blood to confirm pregnancy. It maintains the corpus luteum, which produces progesterone during early pregnancy.
2. Progesterone: This hormone is critical for preparing the uterus for pregnancy and maintaining the pregnancy. It suppresses maternal immune response to prevent rejection of the developing embryo/fetus.
3. Estrogen: This hormone plays a vital role in the growth and development of the fetal brain, as well as promoting the growth of the uterus and mammary glands during pregnancy.
4. Human Placental Lactogen (hPL): This hormone stimulates maternal metabolism to provide nutrients for the developing fetus and helps prepare the breasts for lactation.
5. Relaxin: This hormone relaxes the pelvic ligaments and softens and widens the cervix in preparation for childbirth.

These hormones work together to support fetal growth, maintain pregnancy, and prepare the mother's body for childbirth and lactation.

Speech is the vocalized form of communication using sounds and words to express thoughts, ideas, and feelings. It involves the articulation of sounds through the movement of muscles in the mouth, tongue, and throat, which are controlled by nerves. Speech also requires respiratory support, phonation (vocal cord vibration), and prosody (rhythm, stress, and intonation).

Speech is a complex process that develops over time in children, typically beginning with cooing and babbling sounds in infancy and progressing to the use of words and sentences by around 18-24 months. Speech disorders can affect any aspect of this process, including articulation, fluency, voice, and language.

In a medical context, speech is often evaluated and treated by speech-language pathologists who specialize in diagnosing and managing communication disorders.

Apraxia is a motor disorder characterized by the inability to perform learned, purposeful movements despite having the physical ability and mental understanding to do so. It is not caused by weakness, paralysis, or sensory loss, and it is not due to poor comprehension or motivation.

There are several types of apraxias, including:

1. Limb-Kinematic Apraxia: This type affects the ability to make precise movements with the limbs, such as using tools or performing complex gestures.
2. Ideomotor Apraxia: In this form, individuals have difficulty executing learned motor actions in response to verbal commands or visual cues, but they can still perform the same action when given the actual object to use.
3. Ideational Apraxia: This type affects the ability to sequence and coordinate multiple steps of a complex action, such as dressing oneself or making coffee.
4. Oral Apraxia: Also known as verbal apraxia, this form affects the ability to plan and execute speech movements, leading to difficulties with articulation and speech production.
5. Constructional Apraxia: This type impairs the ability to draw, copy, or construct geometric forms and shapes, often due to visuospatial processing issues.

Apraxias can result from various neurological conditions, such as stroke, brain injury, dementia, or neurodegenerative diseases like Parkinson's disease and Alzheimer's disease. Treatment typically involves rehabilitation and therapy focused on retraining the affected movements and compensating for any residual deficits.

Multiple Sclerosis (MS) is a chronic autoimmune disease that affects the central nervous system (CNS), which includes the brain, spinal cord, and optic nerves. In MS, the immune system mistakenly attacks the protective covering of nerve fibers, called myelin, leading to damage and scarring (sclerosis). This results in disrupted communication between the brain and the rest of the body, causing a variety of neurological symptoms that can vary widely from person to person.

The term "multiple" refers to the numerous areas of scarring that occur throughout the CNS in this condition. The progression, severity, and specific symptoms of MS are unpredictable and may include vision problems, muscle weakness, numbness or tingling, difficulty with balance and coordination, cognitive impairment, and mood changes. There is currently no cure for MS, but various treatments can help manage symptoms, modify the course of the disease, and improve quality of life for those affected.

Neuropsychological tests are a type of psychological assessment that measures cognitive functions, such as attention, memory, language, problem-solving, and perception. These tests are used to help diagnose and understand the cognitive impact of neurological conditions, including dementia, traumatic brain injury, stroke, Parkinson's disease, and other disorders that affect the brain.

The tests are typically administered by a trained neuropsychologist and can take several hours to complete. They may involve paper-and-pencil tasks, computerized tasks, or interactive activities. The results of the tests are compared to normative data to help identify any areas of cognitive weakness or strength.

Neuropsychological testing can provide valuable information for treatment planning, rehabilitation, and assessing response to treatment. It can also be used in research to better understand the neural basis of cognition and the impact of neurological conditions on cognitive function.

Speech Therapy, also known as Speech-Language Pathology, is a medical field that focuses on the assessment, diagnosis, treatment, and prevention of communication and swallowing disorders in children and adults. These disorders may include speech sound production difficulties (articulation disorders or phonological processes disorders), language disorders (expressive and/or receptive language impairments), voice disorders, fluency disorders (stuttering), cognitive-communication disorders, and swallowing difficulties (dysphagia).

Speech therapists, who are also called speech-language pathologists (SLPs), work with clients to improve their communication abilities through various therapeutic techniques and exercises. They may also provide counseling and education to families and caregivers to help them support the client's communication development and management of the disorder.

Speech therapy services can be provided in a variety of settings, including hospitals, clinics, schools, private practices, and long-term care facilities. The specific goals and methods used in speech therapy will depend on the individual needs and abilities of each client.

I'm sorry for any confusion, but "semantics" is not a term that has a specific medical definition. Semantics is actually a branch of linguistics that deals with the study of meaning, reference, and the interpretation of signs and symbols, either individually or in combination. It is used in various fields including computer science, anthropology, psychology, and philosophy.

However, if you have any medical terms or concepts that you would like me to explain, I'd be happy to help!

Conduction aphasia is a type of aphasia that is characterized by an impairment in the ability to repeat spoken or written words, despite having intact comprehension and production abilities. It is caused by damage to specific areas of the brain, typically in the left hemisphere, that are involved in language repetition and transmission.

Individuals with conduction aphasia may have difficulty repeating sentences or phrases, but they can usually understand spoken and written language and produce speech relatively well. They may also make phonological errors (substituting, adding, or omitting sounds) when speaking, particularly in more complex words or sentences.

Conduction aphasia is often caused by stroke or other types of brain injury, and it can range from mild to severe in terms of its impact on communication abilities. Treatment typically involves speech-language therapy to help individuals improve their language skills and compensate for any remaining deficits.

Frontotemporal dementia (FTD) is a group of disorders caused by progressive degeneration of the frontal and temporal lobes of the brain. These areas of the brain are associated with personality, behavior, and language.

There are three main types of FTD:

1. Behavioral variant FTD (bvFTD): This type is characterized by changes in personality, behavior, and judgment. Individuals may become socially inappropriate, emotionally indifferent, or impulsive. They may lose interest in things they used to enjoy and have difficulty with tasks that require planning and organization.

2. Primary progressive aphasia (PPA): This type affects language abilities. There are two main subtypes of PPA: semantic dementia and progressive nonfluent aphasia. Semantic dementia is characterized by difficulty understanding words and objects, while progressive nonfluent aphasia is characterized by problems with speech production and articulation.

3. Motor neuron disease (MND) associated FTD: Some individuals with FTD may also develop motor neuron disease, which affects the nerves that control muscle movement. This can lead to weakness, stiffness, and wasting of muscles, as well as difficulty swallowing and speaking.

FTD is a degenerative disorder, meaning that symptoms get worse over time. There is no cure for FTD, but there are treatments available to help manage symptoms and improve quality of life. The exact cause of FTD is not known, but it is believed to be related to abnormalities in certain proteins in the brain. In some cases, FTD may run in families and be caused by genetic mutations.

Language disorders, also known as communication disorders, refer to a group of conditions that affect an individual's ability to understand or produce spoken, written, or other symbolic language. These disorders can be receptive (difficulty understanding language), expressive (difficulty producing language), or mixed (a combination of both).

Language disorders can manifest as difficulties with grammar, vocabulary, sentence structure, and coherence in communication. They can also affect social communication skills such as taking turns in conversation, understanding nonverbal cues, and interpreting tone of voice.

Language disorders can be developmental, meaning they are present from birth or early childhood, or acquired, meaning they develop later in life due to injury, illness, or trauma. Examples of acquired language disorders include aphasia, which can result from stroke or brain injury, and dysarthria, which can result from neurological conditions affecting speech muscles.

Language disorders can have significant impacts on an individual's academic, social, and vocational functioning, making it important to diagnose and treat them as early as possible. Treatment typically involves speech-language therapy to help individuals develop and improve their language skills.

Medical Definition:

Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic imaging technique that uses a strong magnetic field and radio waves to create detailed cross-sectional or three-dimensional images of the internal structures of the body. The patient lies within a large, cylindrical magnet, and the scanner detects changes in the direction of the magnetic field caused by protons in the body. These changes are then converted into detailed images that help medical professionals to diagnose and monitor various medical conditions, such as tumors, injuries, or diseases affecting the brain, spinal cord, heart, blood vessels, joints, and other internal organs. MRI does not use radiation like computed tomography (CT) scans.

Speech disorders refer to a group of conditions in which a person has difficulty producing or articulating sounds, words, or sentences in a way that is understandable to others. These disorders can be caused by various factors such as developmental delays, neurological conditions, hearing loss, structural abnormalities, or emotional issues.

Speech disorders may include difficulties with:

* Articulation: the ability to produce sounds correctly and clearly.
* Phonology: the sound system of language, including the rules that govern how sounds are combined and used in words.
* Fluency: the smoothness and flow of speech, including issues such as stuttering or cluttering.
* Voice: the quality, pitch, and volume of the spoken voice.
* Resonance: the way sound is produced and carried through the vocal tract, which can affect the clarity and quality of speech.

Speech disorders can impact a person's ability to communicate effectively, leading to difficulties in social situations, academic performance, and even employment opportunities. Speech-language pathologists are trained to evaluate and treat speech disorders using various evidence-based techniques and interventions.

Wernicke's aphasia is a type of fluent aphasia, also known as receptive or sensory aphasia. It is named after the neurologist Carl Wernicke. This type of aphasia is caused by damage to the posterior portion of the left superior temporal gyrus (Wernicke's area) in the dominant hemisphere of the brain, typically as a result of stroke or head injury.

Individuals with Wernicke's aphasia have difficulty understanding spoken or written language. They may speak in long, grammatically correct sentences that are filled with incorrect or made-up words (neologisms) and have little meaning. They are often unaware of their errors and have poor comprehension of both spoken and written language. This can lead to significant difficulties in communication and can be very frustrating for the person with aphasia and their communication partners.

Treatment for Wernicke's aphasia typically involves speech-language therapy, which may focus on improving comprehension, expression, reading, and writing skills. The prognosis for recovery varies depending on the severity of the brain injury and the individual's overall health and cognitive status.

The brain is the central organ of the nervous system, responsible for receiving and processing sensory information, regulating vital functions, and controlling behavior, movement, and cognition. It is divided into several distinct regions, each with specific functions:

1. Cerebrum: The largest part of the brain, responsible for higher cognitive functions such as thinking, learning, memory, language, and perception. It is divided into two hemispheres, each controlling the opposite side of the body.
2. Cerebellum: Located at the back of the brain, it is responsible for coordinating muscle movements, maintaining balance, and fine-tuning motor skills.
3. Brainstem: Connects the cerebrum and cerebellum to the spinal cord, controlling vital functions such as breathing, heart rate, and blood pressure. It also serves as a relay center for sensory information and motor commands between the brain and the rest of the body.
4. Diencephalon: A region that includes the thalamus (a major sensory relay station) and hypothalamus (regulates hormones, temperature, hunger, thirst, and sleep).
5. Limbic system: A group of structures involved in emotional processing, memory formation, and motivation, including the hippocampus, amygdala, and cingulate gyrus.

The brain is composed of billions of interconnected neurons that communicate through electrical and chemical signals. It is protected by the skull and surrounded by three layers of membranes called meninges, as well as cerebrospinal fluid that provides cushioning and nutrients.

Frontotemporal lobar degeneration (FTLD) is a group of disorders characterized by the progressive degeneration of the frontal and temporal lobes of the brain. These areas of the brain are involved in decision-making, behavior, emotion, and language. FTLD can be divided into several subtypes based on the specific clinical features and the underlying protein abnormalities.

The three main subtypes of FTLD are:

1. Behavioral variant frontotemporal dementia (bvFTD): This subtype is characterized by changes in personality, behavior, and judgment. People with bvFTD may lose their social inhibitions, become impulsive, or develop compulsive behaviors. They may also have difficulty with emotional processing and empathy.
2. Primary progressive aphasia (PPA): This subtype is characterized by the gradual deterioration of language skills. People with PPA may have difficulty speaking, understanding spoken or written language, or both. There are three subtypes of PPA: nonfluent/agrammatic variant, semantic variant, and logopenic variant.
3. Motor neuron disease (MND) with FTLD: This subtype is characterized by the degeneration of motor neurons, which are the nerve cells responsible for controlling voluntary muscle movements. People with MND with FTLD may develop symptoms of amyotrophic lateral sclerosis (ALS), such as muscle weakness, stiffness, and twitching, as well as cognitive and behavioral changes associated with FTLD.

The underlying protein abnormalities in FTLD include:

1. Tau protein: In some forms of FTLD, the tau protein accumulates and forms clumps called tangles inside nerve cells. This is also seen in Alzheimer's disease.
2. TDP-43 protein: In other forms of FTLD, the TDP-43 protein accumulates and forms clumps inside nerve cells.
3. Fused in sarcoma (FUS) protein: In a small number of cases, the FUS protein accumulates and forms clumps inside nerve cells.

FTLD is typically a progressive disorder, meaning that symptoms worsen over time. There is currently no cure for FTLD, but there are treatments available to help manage symptoms and improve quality of life.

In the context of medicine, particularly in neurolinguistics and speech-language pathology, language is defined as a complex system of communication that involves the use of symbols (such as words, signs, or gestures) to express and exchange information. It includes various components such as phonology (sound systems), morphology (word structures), syntax (sentence structure), semantics (meaning), and pragmatics (social rules of use). Language allows individuals to convey their thoughts, feelings, and intentions, and to understand the communication of others. Disorders of language can result from damage to specific areas of the brain, leading to impairments in comprehension, production, or both.

Acid Sensing Ion Channel (ASIC) Blockers are a class of pharmaceutical compounds that inhibit the function of ASICs. These channels are activated by decreases in pH, such as those that occur during ischemia and inflammation, and contribute to pain signaling, neuronal excitability, and cell death. By blocking ASICs, these compounds may have potential therapeutic use in the treatment of conditions associated with acid-induced tissue damage, including ischemic stroke, neuropathic pain, and inflammatory diseases. Examples of ASIC blockers include amiloride, ranolazine, and psalmotrin A.

The temporal lobe is one of the four main lobes of the cerebral cortex in the brain, located on each side of the head roughly level with the ears. It plays a major role in auditory processing, memory, and emotion. The temporal lobe contains several key structures including the primary auditory cortex, which is responsible for analyzing sounds, and the hippocampus, which is crucial for forming new memories. Damage to the temporal lobe can result in various neurological symptoms such as hearing loss, memory impairment, and changes in emotional behavior.

Pick's disease, also known as Frontotemporal dementia (FTD), is a rare form of degenerative brain disorder that affects the frontal and temporal lobes of the brain. It is characterized by progressive shrinkage (atrophy) of these regions, resulting in a decline in cognitive abilities, behavioral changes, and language difficulties.

The medical definition of Pick's disease includes the following key features:

1. Progressive deterioration of cognitive functions, including memory, judgment, and problem-solving skills.
2. Changes in personality, emotional blunting, and loss of social inhibitions.
3. Language difficulties, such as difficulty with word finding, grammar, and comprehension.
4. Presence of abnormal protein deposits called Pick bodies or Pick cells in the affected brain regions.
5. Exclusion of other causes of dementia, such as Alzheimer's disease, vascular dementia, or Lewy body dementia.

Pick's disease typically affects people between the ages of 40 and 60, and it tends to progress more rapidly than other forms of dementia. Currently, there is no cure for Pick's disease, and treatment focuses on managing symptoms and improving quality of life.

Language therapy, also known as speech-language therapy, is a type of treatment aimed at improving an individual's communication and swallowing abilities. Speech-language pathologists (SLPs) or therapists provide this therapy to assess, diagnose, and treat a wide range of communication and swallowing disorders that can occur in people of all ages, from infants to the elderly.

Language therapy may involve working on various skills such as:

1. Expressive language: Improving the ability to express thoughts, needs, wants, and ideas through verbal, written, or other symbolic systems.
2. Receptive language: Enhancing the understanding of spoken or written language, including following directions and comprehending conversations.
3. Pragmatic or social language: Developing appropriate use of language in various social situations, such as turn-taking, topic maintenance, and making inferences.
4. Articulation and phonology: Correcting speech sound errors and improving overall speech clarity.
5. Voice and fluency: Addressing issues related to voice quality, volume, and pitch, as well as stuttering or stammering.
6. Literacy: Improving reading, writing, and spelling skills.
7. Swallowing: Evaluating and treating swallowing disorders (dysphagia) to ensure safe and efficient eating and drinking.

Language therapy often involves a combination of techniques, including exercises, drills, conversation practice, and the use of various therapeutic materials and technology. The goal of language therapy is to help individuals with communication disorders achieve optimal functional communication and swallowing abilities in their daily lives.

Disease progression is the worsening or advancement of a medical condition over time. It refers to the natural course of a disease, including its development, the severity of symptoms and complications, and the impact on the patient's overall health and quality of life. Understanding disease progression is important for developing appropriate treatment plans, monitoring response to therapy, and predicting outcomes.

The rate of disease progression can vary widely depending on the type of medical condition, individual patient factors, and the effectiveness of treatment. Some diseases may progress rapidly over a short period of time, while others may progress more slowly over many years. In some cases, disease progression may be slowed or even halted with appropriate medical interventions, while in other cases, the progression may be inevitable and irreversible.

In clinical practice, healthcare providers closely monitor disease progression through regular assessments, imaging studies, and laboratory tests. This information is used to guide treatment decisions and adjust care plans as needed to optimize patient outcomes and improve quality of life.

Neuroimaging is a medical term that refers to the use of various techniques to either directly or indirectly image the structure, function, or pharmacology of the nervous system. It includes techniques such as computed tomography (CT), magnetic resonance imaging (MRI), functional MRI (fMRI), positron emission tomography (PET), single-photon emission computed tomography (SPECT), and diffusion tensor imaging (DTI). These techniques are used to diagnose and monitor various neurological and psychiatric conditions, as well as to understand the underlying mechanisms of brain function in health and disease.

Dementia is a broad term that describes a decline in cognitive functioning, including memory, language, problem-solving, and judgment, severe enough to interfere with daily life. It is not a specific disease but rather a group of symptoms that may be caused by various underlying diseases or conditions. Alzheimer's disease is the most common cause of dementia, accounting for 60-80% of cases. Other causes include vascular dementia, Lewy body dementia, frontotemporal dementia, and Huntington's disease.

The symptoms of dementia can vary widely depending on the cause and the specific areas of the brain that are affected. However, common early signs of dementia may include:

* Memory loss that affects daily life
* Difficulty with familiar tasks
* Problems with language or communication
* Difficulty with visual and spatial abilities
* Misplacing things and unable to retrace steps
* Decreased or poor judgment
* Withdrawal from work or social activities
* Changes in mood or behavior

Dementia is a progressive condition, meaning that symptoms will gradually worsen over time. While there is currently no cure for dementia, early diagnosis and treatment can help slow the progression of the disease and improve quality of life for those affected.

Echolalia is a term used in the field of medicine, specifically in neurology and psychology. It refers to the repetition of words or phrases spoken by another person, mimicking their speech in a near identical manner. This behavior is often observed in individuals with developmental disorders such as autism spectrum disorder (ASD).

Echolalia can be either immediate or delayed. Immediate echolalia occurs when an individual repeats the words or phrases immediately after they are spoken by someone else. Delayed echolalia, on the other hand, involves the repetition of words or phrases that were heard at an earlier time.

Echolalia is not necessarily a pathological symptom and can be a normal part of language development in young children who are learning to speak. However, when it persists beyond the age of 3-4 years or occurs in older individuals with developmental disorders, it may indicate difficulties with initiating spontaneous speech or forming original thoughts and ideas.

In some cases, echolalia can serve as a communication tool for individuals with ASD who have limited verbal abilities. By repeating words or phrases that they have heard before, they may be able to convey their needs or emotions in situations where they are unable to generate appropriate language on their own.

In the context of medical and clinical psychology, particularly in the field of applied behavior analysis (ABA), "verbal behavior" is a term used to describe the various functions or purposes of spoken language. It was first introduced by the psychologist B.F. Skinner in his 1957 book "Verbal Behavior."

Skinner proposed that verbal behavior could be classified into several categories based on its function, including:

1. Mand: A verbal operant in which a person requests or demands something from another person. For example, saying "I would like a glass of water" is a mand.
2. Tact: A verbal operant in which a person describes or labels something in their environment. For example, saying "That's a red apple" is a tact.
3. Echoic: A verbal operant in which a person repeats or imitates what they have heard. For example, saying "Hello" after someone says hello to you is an echoic.
4. Intraverbal: A verbal operant in which a person responds to another person's verbal behavior with their own verbal behavior, without simply repeating or imitating what they have heard. For example, answering a question like "What's the capital of France?" is an intraverbal.
5. Textual: A verbal operant in which a person reads or writes text. For example, reading a book or writing a letter are textual.

Understanding the function of verbal behavior can be helpful in assessing and treating communication disorders, such as those seen in autism spectrum disorder (ASD). By identifying the specific functions of a child's verbal behavior, therapists can develop targeted interventions to help them communicate more effectively.

Diffusion Tensor Imaging (DTI) is a type of magnetic resonance imaging (MRI) technique that allows for the measurement and visualization of water diffusion in biological tissues, particularly in the brain. DTI provides information about the microstructural organization and integrity of nerve fibers within the brain by measuring the directionality of water diffusion in the brain's white matter tracts.

In DTI, a tensor is used to describe the three-dimensional diffusion properties of water molecules in each voxel (three-dimensional pixel) of an MRI image. The tensor provides information about the magnitude and direction of water diffusion, which can be used to calculate various diffusion metrics such as fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD). These metrics provide insights into the structural properties of nerve fibers, including their orientation, density, and integrity.

DTI has numerous clinical applications, such as in the diagnosis and monitoring of neurological disorders like multiple sclerosis, traumatic brain injury, and neurodegenerative diseases. It can also be used for presurgical planning to identify critical white matter tracts that need to be preserved during surgery.

Comprehension, in a medical context, usually refers to the ability to understand and interpret spoken or written language, as well as gestures and expressions. It is a key component of communication and cognitive functioning. Difficulties with comprehension can be a symptom of various neurological conditions, such as aphasia (a disorder caused by damage to the language areas of the brain), learning disabilities, or dementia. Assessment of comprehension is often part of neuropsychological evaluations and speech-language pathology assessments.

The frontal lobe is the largest lobes of the human brain, located at the front part of each cerebral hemisphere and situated in front of the parietal and temporal lobes. It plays a crucial role in higher cognitive functions such as decision making, problem solving, planning, parts of social behavior, emotional expressions, physical reactions, and motor function. The frontal lobe is also responsible for what's known as "executive functions," which include the ability to focus attention, understand rules, switch focus, plan actions, and inhibit inappropriate behaviors. It is divided into five areas, each with its own specific functions: the primary motor cortex, premotor cortex, Broca's area, prefrontal cortex, and orbitofrontal cortex. Damage to the frontal lobe can result in a wide range of impairments, depending on the location and extent of the injury.

Brain mapping is a broad term that refers to the techniques used to understand the structure and function of the brain. It involves creating maps of the various cognitive, emotional, and behavioral processes in the brain by correlating these processes with physical locations or activities within the nervous system. Brain mapping can be accomplished through a variety of methods, including functional magnetic resonance imaging (fMRI), positron emission tomography (PET) scans, electroencephalography (EEG), and others. These techniques allow researchers to observe which areas of the brain are active during different tasks or thoughts, helping to shed light on how the brain processes information and contributes to our experiences and behaviors. Brain mapping is an important area of research in neuroscience, with potential applications in the diagnosis and treatment of neurological and psychiatric disorders.

Alzheimer's disease is a progressive disorder that causes brain cells to waste away (degenerate) and die. It's the most common cause of dementia — a continuous decline in thinking, behavioral and social skills that disrupts a person's ability to function independently.

The early signs of the disease include forgetting recent events or conversations. As the disease progresses, a person with Alzheimer's disease will develop severe memory impairment and lose the ability to carry out everyday tasks.

Currently, there's no cure for Alzheimer's disease. However, treatments can temporarily slow the worsening of dementia symptoms and improve quality of life.

Spontaneous remission in a medical context refers to the disappearance or significant improvement of symptoms of a disease or condition without any specific treatment being administered. In other words, it's a situation where the disease resolves on its own, without any apparent cause. While spontaneous remission can occur in various conditions, it is relatively rare and not well understood. It's important to note that just because a remission occurs without treatment doesn't mean that medical care should be avoided, as many conditions can worsen or lead to complications if left untreated.

The Medical Definition of 'Mental Status Schedule' is:

A standardized interview and examination tool used by mental health professionals to assess an individual's cognitive, behavioral, and emotional status. The schedule typically covers areas such as orientation, attention, memory, language, visuospatial abilities, executive functions, and mood and affect. It is often used in research, clinical settings, and epidemiological studies to evaluate psychiatric and neurological conditions, as well as the effects of treatments or interventions. The specific version of the Mental Status Schedule may vary, but it generally includes a structured format with clear questions and response options to ensure standardization and reliability in the assessment process.

Functional laterality, in a medical context, refers to the preferential use or performance of one side of the body over the other for specific functions. This is often demonstrated in hand dominance, where an individual may be right-handed or left-handed, meaning they primarily use their right or left hand for tasks such as writing, eating, or throwing.

However, functional laterality can also apply to other bodily functions and structures, including the eyes (ocular dominance), ears (auditory dominance), or legs. It's important to note that functional laterality is not a strict binary concept; some individuals may exhibit mixed dominance or no strong preference for one side over the other.

In clinical settings, assessing functional laterality can be useful in diagnosing and treating various neurological conditions, such as stroke or traumatic brain injury, where understanding any resulting lateralized impairments can inform rehabilitation strategies.

Computer-assisted image processing is a medical term that refers to the use of computer systems and specialized software to improve, analyze, and interpret medical images obtained through various imaging techniques such as X-ray, CT (computed tomography), MRI (magnetic resonance imaging), ultrasound, and others.

The process typically involves several steps, including image acquisition, enhancement, segmentation, restoration, and analysis. Image processing algorithms can be used to enhance the quality of medical images by adjusting contrast, brightness, and sharpness, as well as removing noise and artifacts that may interfere with accurate diagnosis. Segmentation techniques can be used to isolate specific regions or structures of interest within an image, allowing for more detailed analysis.

Computer-assisted image processing has numerous applications in medical imaging, including detection and characterization of lesions, tumors, and other abnormalities; assessment of organ function and morphology; and guidance of interventional procedures such as biopsies and surgeries. By automating and standardizing image analysis tasks, computer-assisted image processing can help to improve diagnostic accuracy, efficiency, and consistency, while reducing the potential for human error.

A neurological examination is a series of tests used to evaluate the functioning of the nervous system, including both the central nervous system (the brain and spinal cord) and peripheral nervous system (the nerves that extend from the brain and spinal cord to the rest of the body). It is typically performed by a healthcare professional such as a neurologist or a primary care physician with specialized training in neurology.

During a neurological examination, the healthcare provider will assess various aspects of neurological function, including:

1. Mental status: This involves evaluating a person's level of consciousness, orientation, memory, and cognitive abilities.
2. Cranial nerves: There are 12 cranial nerves that control functions such as vision, hearing, smell, taste, and movement of the face and neck. The healthcare provider will test each of these nerves to ensure they are functioning properly.
3. Motor function: This involves assessing muscle strength, tone, coordination, and reflexes. The healthcare provider may ask the person to perform certain movements or tasks to evaluate these functions.
4. Sensory function: The healthcare provider will test a person's ability to feel different types of sensations, such as touch, pain, temperature, vibration, and proprioception (the sense of where your body is in space).
5. Coordination and balance: The healthcare provider may assess a person's ability to perform coordinated movements, such as touching their finger to their nose or walking heel-to-toe.
6. Reflexes: The healthcare provider will test various reflexes throughout the body using a reflex hammer.

The results of a neurological examination can help healthcare providers diagnose and monitor conditions that affect the nervous system, such as stroke, multiple sclerosis, Parkinson's disease, or peripheral neuropathy.

The cerebral cortex is the outermost layer of the brain, characterized by its intricate folded structure and wrinkled appearance. It is a region of great importance as it plays a key role in higher cognitive functions such as perception, consciousness, thought, memory, language, and attention. The cerebral cortex is divided into two hemispheres, each containing four lobes: the frontal, parietal, temporal, and occipital lobes. These areas are responsible for different functions, with some regions specializing in sensory processing while others are involved in motor control or associative functions. The cerebral cortex is composed of gray matter, which contains neuronal cell bodies, and is covered by a layer of white matter that consists mainly of myelinated nerve fibers.

A Severity of Illness Index is a measurement tool used in healthcare to assess the severity of a patient's condition and the risk of mortality or other adverse outcomes. These indices typically take into account various physiological and clinical variables, such as vital signs, laboratory values, and co-morbidities, to generate a score that reflects the patient's overall illness severity.

Examples of Severity of Illness Indices include the Acute Physiology and Chronic Health Evaluation (APACHE) system, the Simplified Acute Physiology Score (SAPS), and the Mortality Probability Model (MPM). These indices are often used in critical care settings to guide clinical decision-making, inform prognosis, and compare outcomes across different patient populations.

It is important to note that while these indices can provide valuable information about a patient's condition, they should not be used as the sole basis for clinical decision-making. Rather, they should be considered in conjunction with other factors, such as the patient's overall clinical presentation, treatment preferences, and goals of care.

Disability Evaluation is the process of determining the nature and extent of a person's functional limitations or impairments, and assessing their ability to perform various tasks and activities in order to determine eligibility for disability benefits or accommodations. This process typically involves a medical examination and assessment by a licensed healthcare professional, such as a physician or psychologist, who evaluates the individual's symptoms, medical history, laboratory test results, and functional abilities. The evaluation may also involve input from other professionals, such as vocational experts, occupational therapists, or speech-language pathologists, who can provide additional information about the person's ability to perform specific tasks and activities in a work or daily living context. Based on this information, a determination is made about whether the individual meets the criteria for disability as defined by the relevant governing authority, such as the Social Security Administration or the Americans with Disabilities Act.

Cognitive disorders are a category of mental health disorders that primarily affect cognitive abilities including learning, memory, perception, and problem-solving. These disorders can be caused by various factors such as brain injury, degenerative diseases, infection, substance abuse, or developmental disabilities. Examples of cognitive disorders include dementia, amnesia, delirium, and intellectual disability. It's important to note that the specific definition and diagnostic criteria for cognitive disorders may vary depending on the medical source or classification system being used.

A case-control study is an observational research design used to identify risk factors or causes of a disease or health outcome. In this type of study, individuals with the disease or condition (cases) are compared with similar individuals who do not have the disease or condition (controls). The exposure history or other characteristics of interest are then compared between the two groups to determine if there is an association between the exposure and the disease.

Case-control studies are often used when it is not feasible or ethical to conduct a randomized controlled trial, as they can provide valuable insights into potential causes of diseases or health outcomes in a relatively short period of time and at a lower cost than other study designs. However, because case-control studies rely on retrospective data collection, they are subject to biases such as recall bias and selection bias, which can affect the validity of the results. Therefore, it is important to carefully design and conduct case-control studies to minimize these potential sources of bias.

Aniline compounds, also known as aromatic amines, are organic compounds that contain a benzene ring substituted with an amino group (-NH2). Aniline itself is the simplest and most common aniline compound, with the formula C6H5NH2.

Aniline compounds are important in the chemical industry and are used in the synthesis of a wide range of products, including dyes, pharmaceuticals, and rubber chemicals. They can be produced by reducing nitrobenzene or by directly substituting ammonia onto benzene in a process called amination.

It is important to note that aniline compounds are toxic and can cause serious health effects, including damage to the liver, kidneys, and central nervous system. They can also be absorbed through the skin and are known to have carcinogenic properties. Therefore, appropriate safety measures must be taken when handling aniline compounds.

The "age of onset" is a medical term that refers to the age at which an individual first develops or displays symptoms of a particular disease, disorder, or condition. It can be used to describe various medical conditions, including both physical and mental health disorders. The age of onset can have implications for prognosis, treatment approaches, and potential causes of the condition. In some cases, early onset may indicate a more severe or progressive course of the disease, while late-onset symptoms might be associated with different underlying factors or etiologies. It is essential to provide accurate and precise information regarding the age of onset when discussing a patient's medical history and treatment plan.

The spinal cord is a major part of the nervous system, extending from the brainstem and continuing down to the lower back. It is a slender, tubular bundle of nerve fibers (axons) and support cells (glial cells) that carries signals between the brain and the rest of the body. The spinal cord primarily serves as a conduit for motor information, which travels from the brain to the muscles, and sensory information, which travels from the body to the brain. It also contains neurons that can independently process and respond to information within the spinal cord without direct input from the brain.

The spinal cord is protected by the bony vertebral column (spine) and is divided into 31 segments: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal. Each segment corresponds to a specific region of the body and gives rise to pairs of spinal nerves that exit through the intervertebral foramina at each level.

The spinal cord is responsible for several vital functions, including:

1. Reflexes: Simple reflex actions, such as the withdrawal reflex when touching a hot surface, are mediated by the spinal cord without involving the brain.
2. Muscle control: The spinal cord carries motor signals from the brain to the muscles, enabling voluntary movement and muscle tone regulation.
3. Sensory perception: The spinal cord transmits sensory information, such as touch, temperature, pain, and vibration, from the body to the brain for processing and awareness.
4. Autonomic functions: The sympathetic and parasympathetic divisions of the autonomic nervous system originate in the thoracolumbar and sacral regions of the spinal cord, respectively, controlling involuntary physiological responses like heart rate, blood pressure, digestion, and respiration.

Damage to the spinal cord can result in various degrees of paralysis or loss of sensation below the level of injury, depending on the severity and location of the damage.

Computer-assisted image interpretation is the use of computer algorithms and software to assist healthcare professionals in analyzing and interpreting medical images. These systems use various techniques such as pattern recognition, machine learning, and artificial intelligence to help identify and highlight abnormalities or patterns within imaging data, such as X-rays, CT scans, MRI, and ultrasound images. The goal is to increase the accuracy, consistency, and efficiency of image interpretation, while also reducing the potential for human error. It's important to note that these systems are intended to assist healthcare professionals in their decision making process and not to replace them.

Positron-Emission Tomography (PET) is a type of nuclear medicine imaging that uses small amounts of radioactive material, called a radiotracer, to produce detailed, three-dimensional images. This technique measures metabolic activity within the body, such as sugar metabolism, to help distinguish between healthy and diseased tissue, identify cancerous cells, or examine the function of organs.

During a PET scan, the patient is injected with a radiotracer, typically a sugar-based compound labeled with a positron-emitting radioisotope, such as fluorine-18 (^18^F). The radiotracer accumulates in cells that are metabolically active, like cancer cells. As the radiotracer decays, it emits positrons, which then collide with electrons in nearby tissue, producing gamma rays. A special camera, called a PET scanner, detects these gamma rays and uses this information to create detailed images of the body's internal structures and processes.

PET is often used in conjunction with computed tomography (CT) or magnetic resonance imaging (MRI) to provide both functional and anatomical information, allowing for more accurate diagnosis and treatment planning. Common applications include detecting cancer recurrence, staging and monitoring cancer, evaluating heart function, and assessing brain function in conditions like dementia and epilepsy.

Acquired dyslexia, also known as "alexia" or "word blindness," is a medical condition that affects an individual's ability to understand written language despite having normal intelligence and education. It is characterized by a sudden loss of the ability to read, following damage to specific areas of the brain responsible for visual processing and language comprehension, such as the left occipitotemporal cortex.

Unlike developmental dyslexia, which is present from birth or early childhood, acquired dyslexia occurs later in life due to brain injury, stroke, infection, tumor, or other neurological conditions that damage the language and visual processing areas of the brain. Individuals with acquired dyslexia may have difficulty recognizing words, letters, or symbols, despite having intact hearing and speaking abilities.

Treatment for acquired dyslexia typically involves rehabilitation and compensation strategies to help the individual regain their reading skills or develop alternative ways to process written language. Speech-language therapy, occupational therapy, and assistive technology may be used as part of a comprehensive treatment plan.

Myelinated nerve fibers are neuronal processes that are surrounded by a myelin sheath, a fatty insulating substance that is produced by Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system. This myelin sheath helps to increase the speed of electrical impulse transmission, also known as action potentials, along the nerve fiber. The myelin sheath has gaps called nodes of Ranvier where the electrical impulses can jump from one node to the next, which also contributes to the rapid conduction of signals. Myelinated nerve fibers are typically found in the peripheral nerves and the optic nerve, but not in the central nervous system (CNS) tracts that are located within the brain and spinal cord.

Speech production measurement is the quantitative analysis and assessment of various parameters and characteristics of spoken language, such as speech rate, intensity, duration, pitch, and articulation. These measurements can be used to diagnose and monitor speech disorders, evaluate the effectiveness of treatment, and conduct research in fields such as linguistics, psychology, and communication disorders. Speech production measurement tools may include specialized software, hardware, and techniques for recording, analyzing, and visualizing speech data.

I'm sorry for any confusion, but "linguistics" is not a term that has a medical definition. Lingustics is the scientific study of language and its structure. It involves analysing language form, language meaning, and language in context.

If you have any questions related to healthcare or medicine, I'd be happy to try to help answer them!

Nerve degeneration, also known as neurodegeneration, is the progressive loss of structure and function of neurons, which can lead to cognitive decline, motor impairment, and various other symptoms. This process occurs due to a variety of factors, including genetics, environmental influences, and aging. It is a key feature in several neurological disorders such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and multiple sclerosis. The degeneration can affect any part of the nervous system, leading to different symptoms depending on the location and extent of the damage.

Nonparametric statistics is a branch of statistics that does not rely on assumptions about the distribution of variables in the population from which the sample is drawn. In contrast to parametric methods, nonparametric techniques make fewer assumptions about the data and are therefore more flexible in their application. Nonparametric tests are often used when the data do not meet the assumptions required for parametric tests, such as normality or equal variances.

Nonparametric statistical methods include tests such as the Wilcoxon rank-sum test (also known as the Mann-Whitney U test) for comparing two independent groups, the Wilcoxon signed-rank test for comparing two related groups, and the Kruskal-Wallis test for comparing more than two independent groups. These tests use the ranks of the data rather than the actual values to make comparisons, which allows them to be used with ordinal or continuous data that do not meet the assumptions of parametric tests.

Overall, nonparametric statistics provide a useful set of tools for analyzing data in situations where the assumptions of parametric methods are not met, and can help researchers draw valid conclusions from their data even when the data are not normally distributed or have other characteristics that violate the assumptions of parametric tests.

A stroke, also known as cerebrovascular accident (CVA), is a serious medical condition that occurs when the blood supply to part of the brain is interrupted or reduced, leading to deprivation of oxygen and nutrients to brain cells. This can result in the death of brain tissue and cause permanent damage or temporary impairment to cognitive functions, speech, memory, movement, and other body functions controlled by the affected area of the brain.

Strokes can be caused by either a blockage in an artery that supplies blood to the brain (ischemic stroke) or the rupture of a blood vessel in the brain (hemorrhagic stroke). A transient ischemic attack (TIA), also known as a "mini-stroke," is a temporary disruption of blood flow to the brain that lasts only a few minutes and does not cause permanent damage.

Symptoms of a stroke may include sudden weakness or numbness in the face, arm, or leg; difficulty speaking or understanding speech; vision problems; loss of balance or coordination; severe headache with no known cause; and confusion or disorientation. Immediate medical attention is crucial for stroke patients to receive appropriate treatment and prevent long-term complications.

A nerve net, also known as a neural net or neuronal network, is not a medical term per se, but rather a concept in neuroscience and artificial intelligence (AI). It refers to a complex network of interconnected neurons that process and transmit information. In the context of the human body, the nervous system can be thought of as a type of nerve net, with the brain and spinal cord serving as the central processing unit and peripheral nerves carrying signals to and from various parts of the body.

In the field of AI, artificial neural networks are computational models inspired by the structure and function of biological nerve nets. These models consist of interconnected nodes or "neurons" that process information and learn patterns through a process of training and adaptation. They have been used in a variety of applications, including image recognition, natural language processing, and machine learning.

Progressive Supranuclear Palsy (PSP) is a rare neurological disorder characterized by the progressive degeneration of brain cells that regulate movement, thoughts, behavior, and eye movements. The term "supranuclear" refers to the location of the damage in the brain, specifically above the level of the "nuclei" which are clusters of nerve cells that control voluntary movements.

The most common early symptom of PSP is a loss of balance and difficulty coordinating eye movements, particularly vertical gaze. Other symptoms may include stiffness or rigidity of muscles, slowness of movement, difficulty swallowing, changes in speech and writing, and cognitive decline leading to dementia.

PSP typically affects people over the age of 60, and its progression can vary from person to person. Currently, there is no cure for PSP, and treatment is focused on managing symptoms and maintaining quality of life.

Recurrence, in a medical context, refers to the return of symptoms or signs of a disease after a period of improvement or remission. It indicates that the condition has not been fully eradicated and may require further treatment. Recurrence is often used to describe situations where a disease such as cancer comes back after initial treatment, but it can also apply to other medical conditions. The likelihood of recurrence varies depending on the type of disease and individual patient factors.

Psychomotor performance refers to the integration and coordination of mental processes (cognitive functions) with physical movements. It involves the ability to perform complex tasks that require both cognitive skills, such as thinking, remembering, and perceiving, and motor skills, such as gross and fine motor movements. Examples of psychomotor performances include driving a car, playing a musical instrument, or performing surgical procedures.

In a medical context, psychomotor performance is often used to assess an individual's ability to perform activities of daily living (ADLs) and instrumental activities of daily living (IADLs), such as bathing, dressing, cooking, cleaning, and managing medications. Deficits in psychomotor performance can be a sign of neurological or psychiatric disorders, such as dementia, Parkinson's disease, or depression.

Assessment of psychomotor performance may involve tests that measure reaction time, coordination, speed, precision, and accuracy of movements, as well as cognitive functions such as attention, memory, and problem-solving skills. These assessments can help healthcare professionals develop appropriate treatment plans and monitor the progression of diseases or the effectiveness of interventions.

I'm sorry for any confusion, but "names" is not a medical term that can be defined in a biological or clinical context. If you have any questions about medical terminology or concepts, I would be happy to try and help! Please provide more information or clarify your question.

X-ray computed tomography (CT or CAT scan) is a medical imaging method that uses computer-processed combinations of many X-ray images taken from different angles to produce cross-sectional (tomographic) images (virtual "slices") of the body. These cross-sectional images can then be used to display detailed internal views of organs, bones, and soft tissues in the body.

The term "computed tomography" is used instead of "CT scan" or "CAT scan" because the machines take a series of X-ray measurements from different angles around the body and then use a computer to process these data to create detailed images of internal structures within the body.

CT scanning is a noninvasive, painless medical test that helps physicians diagnose and treat medical conditions. CT imaging provides detailed information about many types of tissue including lung, bone, soft tissue and blood vessels. CT examinations can be performed on every part of the body for a variety of reasons including diagnosis, surgical planning, and monitoring of therapeutic responses.

In computed tomography (CT), an X-ray source and detector rotate around the patient, measuring the X-ray attenuation at many different angles. A computer uses this data to construct a cross-sectional image by the process of reconstruction. This technique is called "tomography". The term "computed" refers to the use of a computer to reconstruct the images.

CT has become an important tool in medical imaging and diagnosis, allowing radiologists and other physicians to view detailed internal images of the body. It can help identify many different medical conditions including cancer, heart disease, lung nodules, liver tumors, and internal injuries from trauma. CT is also commonly used for guiding biopsies and other minimally invasive procedures.

In summary, X-ray computed tomography (CT or CAT scan) is a medical imaging technique that uses computer-processed combinations of many X-ray images taken from different angles to produce cross-sectional images of the body. It provides detailed internal views of organs, bones, and soft tissues in the body, allowing physicians to diagnose and treat medical conditions.

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