Periventricular Nodular Heterotopia
Filamins
Contractile Proteins
Cerebral Ventricles
Brain Diseases
Leukomalacia, Periventricular
Microfilament Proteins
Magnetic Resonance Imaging
Methylazoxymethanol Acetate
Malformations of Cortical Development
Classical Lissencephalies and Subcortical Band Heterotopias
Epilepsy
Neuronal Migration Disorders
De Morsier syndrome associated with periventricular nodular heterotopia: case report. (1/24)
INTRODUCTION: Septo-optic dysplasia (De Morsier syndrome) is defined as the association between optic nerve hypoplasia, midline central nervous system malformations and pituitary dysfunction. CASE REPORT: Third child born to nonconsanguineous parents, female, adequate pre-natal medical care, cesarean term delivery due to breech presentation, Apgar score 3 at the first minute and 8 at 5 minutes, symptomatic hypoglycemia at 18 hours. Neurological follow-up identified a delay in acquisition of motor and language developmental milestones. Epileptic generalized seizures began at 12 months and were controlled with phenobarbital. EEG was normal. MRI revealed agenesis of the pituitary stalk, hypoplasia of the optic chiasm and periventricular nodular heterotopia. Ophthalmologic evaluation showed bilateral optic disk hypoplasia. Endocrine function laboratory tests revealed primary hypothyroidism and hyperprolactinemia. CONCLUSION: The relevance of this case report relies on its uniqueness, since periventricular heterotopia had not been described in association with septo-optic dysplasia until 2006. (+info)Malformations of cortical development and epilepsy. (2/24)
Malformations of cortical development (MCDs) are macroscopic or microscopic abnormalities of the cerebral cortex that arise as a consequence of an interruption to the normal steps of formation of the cortical plate. The human cortex develops its basic structure during the first two trimesters of pregnancy as a series of overlapping steps, beginning with proliferation and differentiation of neurons, which then migrate before finally organizing themselves in the developing cortex. Abnormalities at any of these stages, be they environmental or genetic in origin, may cause disruption of neuronal circuitry and predispose to a variety of clinical consequences, the most common of which is epileptic seizures. A large number of MCDs have now been described, each with characteristic pathological, clinical, and imaging features. The causes of many of these MCDs have been determined through the study of affected individuals, with many MCDs now established as being secondary to mutations in cortical development genes. This review will highlight the best-known of the human cortical malformations associated with epilepsy. The pathological, clinical, imaging, and etiologic features of each MCD will be summarized, with representative magnetic resonance imaging (MRI) images shown for each MCD. The malformations tuberous sclerosis, focal cortical dysplasia, hemimegalencephaly, classical lissencephaly, subcortical band heterotopia, periventricular nodular heterotopia, polymicrogyria, and schizencephaly will be presented. (+info)Neuroimaging aspects of Aicardi syndrome. (3/24)
(+info)Disruption of neural progenitors along the ventricular and subventricular zones in periventricular heterotopia. (4/24)
(+info)Movement disorder and neuronal migration disorder due to ARFGEF2 mutation. (5/24)
(+info)Gray matter volumes and cognitive ability in the epileptogenic brain malformation of periventricular nodular heterotopia. (6/24)
(+info)Spred1, a negative regulator of Ras-MAPK-ERK, is enriched in CNS germinal zones, dampens NSC proliferation, and maintains ventricular zone structure. (7/24)
(+info)Absence epilepsy and periventricular nodular heterotopia. (8/24)
(+info)Periventricular Nodular Heterotopia (PNH) is a type of brain malformation where nodules or clusters of gray matter are abnormally located in the periventricular region, which is the area surrounding the ventricles (fluid-filled spaces) within the brain. These nodules fail to migrate to their proper location during brain development, resulting in the heterotopia or misplacement of neurons.
PNH can be classified into two types: symmetrical and asymmetrical. Symmetrical PNH is characterized by bilateral, symmetric nodules along the lateral ventricles, while asymmetrical PNH presents with unilateral or asymmetric nodular distribution. The condition may occur as an isolated finding (nonsyndromic) or in association with other brain abnormalities and genetic disorders (syndromic).
The severity of symptoms associated with Periventricular Nodular Heterotopia varies widely, ranging from normal cognitive function to various neurological impairments such as epilepsy, intellectual disability, and motor deficits. The presence of PNH may increase the risk for developing seizures, particularly in cases where nodules are large or located near the cortex. Treatment typically focuses on managing symptoms, including antiepileptic drugs to control seizures and rehabilitation therapies to address any neurological deficits.
A choristoma is a type of growth that occurs when normally functioning tissue is found in an abnormal location within the body. It is not cancerous or harmful, but it can cause problems if it presses on surrounding structures or causes symptoms. Choristomas are typically congenital, meaning they are present at birth, and are thought to occur due to developmental errors during embryonic growth. They can be found in various organs and tissues throughout the body, including the brain, eye, skin, and gastrointestinal tract.
Filamins are a group of proteins that play a crucial role in the structure and function of the cytoskeleton, which is the internal framework of cells. They belong to a family of proteins known as "cytoskeletal cross-linking proteins." There are three main types of filamins (A, B, and C) in humans, encoded by different genes but sharing similar structures and functions.
Filamins have several domains that allow them to interact with various cellular components, including actin filaments, membrane receptors, signaling molecules, and other structural proteins. One of their primary roles is to connect actin filaments to each other and to other cellular structures, providing stability and organization to the cytoskeleton. This helps maintain cell shape, facilitate cell movement, and enable proper intracellular transport.
Additionally, filamins are involved in various signaling pathways and can regulate cellular processes such as gene expression, cell proliferation, differentiation, and survival. Dysregulation of filamin function has been implicated in several diseases, including cancer, cardiovascular disorders, neurological conditions, and musculoskeletal disorders.
Contractile proteins are a type of protein found in muscle cells that are responsible for the ability of the muscle to contract and generate force. The two main types of contractile proteins are actin and myosin, which are arranged in sarcomeres, the functional units of muscle fibers. When stimulated by a nerve impulse, actin and myosin filaments slide past each other, causing the muscle to shorten and generate force. This process is known as excitation-contraction coupling. Other proteins, such as tropomyosin and troponin, regulate the interaction between actin and myosin and control muscle contraction.
The cerebral ventricles are a system of interconnected fluid-filled cavities within the brain. They are located in the center of the brain and are filled with cerebrospinal fluid (CSF), which provides protection to the brain by cushioning it from impacts and helping to maintain its stability within the skull.
There are four ventricles in total: two lateral ventricles, one third ventricle, and one fourth ventricle. The lateral ventricles are located in each cerebral hemisphere, while the third ventricle is located between the thalami of the two hemispheres. The fourth ventricle is located at the base of the brain, above the spinal cord.
CSF flows from the lateral ventricles into the third ventricle through narrow passageways called the interventricular foramen. From there, it flows into the fourth ventricle through another narrow passageway called the cerebral aqueduct. CSF then leaves the fourth ventricle and enters the subarachnoid space surrounding the brain and spinal cord, where it can be absorbed into the bloodstream.
Abnormalities in the size or shape of the cerebral ventricles can indicate underlying neurological conditions, such as hydrocephalus (excessive accumulation of CSF) or atrophy (shrinkage) of brain tissue. Imaging techniques, such as computed tomography (CT) or magnetic resonance imaging (MRI), are often used to assess the size and shape of the cerebral ventricles in clinical settings.
Brain diseases, also known as neurological disorders, refer to a wide range of conditions that affect the brain and nervous system. These diseases can be caused by various factors such as genetics, infections, injuries, degeneration, or structural abnormalities. They can affect different parts of the brain, leading to a variety of symptoms and complications.
Some examples of brain diseases include:
1. Alzheimer's disease - a progressive degenerative disorder that affects memory and cognitive function.
2. Parkinson's disease - a movement disorder characterized by tremors, stiffness, and difficulty with coordination and balance.
3. Multiple sclerosis - a chronic autoimmune disease that affects the nervous system and can cause a range of symptoms such as vision loss, muscle weakness, and cognitive impairment.
4. Epilepsy - a neurological disorder characterized by recurrent seizures.
5. Brain tumors - abnormal growths in the brain that can be benign or malignant.
6. Stroke - a sudden interruption of blood flow to the brain, which can cause paralysis, speech difficulties, and other neurological symptoms.
7. Meningitis - an infection of the membranes surrounding the brain and spinal cord.
8. Encephalitis - an inflammation of the brain that can be caused by viruses, bacteria, or autoimmune disorders.
9. Huntington's disease - a genetic disorder that affects muscle coordination, cognitive function, and mental health.
10. Migraine - a neurological condition characterized by severe headaches, often accompanied by nausea, vomiting, and sensitivity to light and sound.
Brain diseases can range from mild to severe and may be treatable or incurable. They can affect people of all ages and backgrounds, and early diagnosis and treatment are essential for improving outcomes and quality of life.
Periventricular leukomalacia (PVL) is a medical condition that refers to the damage and softening (leukomalacia) of white matter in the brain around the ventricles, which are fluid-filled spaces near the center of the brain. This damage primarily affects the preterm infants, particularly those born before 32 weeks of gestation and weighing less than 1500 grams.
PVL is caused by a decrease in blood flow and oxygen to the periventricular area of the brain, leading to the death of brain cells (infarction) and subsequent scarring (gliosis). The damage to the white matter can result in various neurological problems such as cerebral palsy, developmental delays, visual impairments, and hearing difficulties.
The severity of PVL can vary from mild to severe, with more severe cases resulting in significant neurological deficits. The diagnosis is typically made through imaging techniques like ultrasound, CT, or MRI scans. Currently, there is no specific treatment for PVL, and management focuses on addressing the symptoms and preventing further complications.
Microfilament proteins are a type of structural protein that form part of the cytoskeleton in eukaryotic cells. They are made up of actin monomers, which polymerize to form long, thin filaments. These filaments are involved in various cellular processes such as muscle contraction, cell division, and cell motility. Microfilament proteins also interact with other cytoskeletal components like intermediate filaments and microtubules to maintain the overall shape and integrity of the cell. Additionally, they play a crucial role in the formation of cell-cell junctions and cell-matrix adhesions, which are essential for tissue structure and function.
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.
Methylazoxymethanol Acetate (MAM) is not a medication or therapeutic agent used in human medicine. It is a research tool, specifically a neurotoxin, that is used in laboratory studies to help understand the development and organization of the nervous system, particularly in relation to neurodegenerative disorders and brain injuries.
MAM is primarily used in animal models, often rats or mice, to study the effects of early life exposure to neurotoxic substances on brain development. It is known to cause widespread degeneration of nerve cells (neurons) and disruption of normal neural connections, which can provide valuable insights into the processes underlying various neurological conditions.
However, it's important to note that MAM is not used as a treatment or therapy in human medicine due to its neurotoxic properties.
Malformations of Cortical Development (MCDs) are a group of congenital brain abnormalities that occur during the development and organization of the cerebral cortex, which is the brain region responsible for higher cognitive functions. These malformations result from disruptions in neuronal migration, proliferation, or organization, leading to varying degrees of cortical thickness, folding, and structural integrity.
MCDs can be classified into several subtypes based on their distinct neuroimaging and histopathological features. Some common MCD subtypes include:
1. Lissencephaly (smooth brain): A severe malformation characterized by the absence of normal gyral and sulcal patterns, resulting in a smooth cortical surface. This is caused by defects in neuronal migration during early development.
2. Polymicrogyria (many small folds): A condition where the cortex has an excessive number of small, irregular gyri, leading to thickened and disorganized cortical layers. This can be focal or diffuse and is caused by abnormal neuronal migration or organization during mid to late development.
3. Schizencephaly (cleft brain): A malformation characterized by a linear cleft or gap in the cerebral cortex, extending from the pial surface to the ventricular system. This can be unilateral or bilateral and is caused by disruptions in neuronal migration and/or cortical organization during early development.
4. Heterotopias (misplaced cells): A condition where groups of neurons are abnormally located within the white matter or at the gray-white matter junction, instead of their normal position in the cerebral cortex. This can be focal or diffuse and is caused by defects in neuronal migration during early development.
5. Focal cortical dysplasia (abnormal localized tissue): A condition characterized by abnormal cortical architecture, including disorganized lamination, enlarged neurons, and heterotopic neurons. This can be focal or multifocal and is caused by defects in cortical organization during late development.
MCDs are often associated with neurological symptoms such as epilepsy, intellectual disability, motor deficits, and behavioral abnormalities. The severity of these symptoms depends on the type, location, and extent of the malformation.
Classical lissencephaly and subcortical band heterotopia are rare neurological conditions that affect the development of the brain. These conditions are characterized by abnormal migration of nerve cells (neurons) during fetal development, leading to a smooth brain surface or disorganized layers of neurons.
Classical lissencephaly, also known as "smooth brain," is a condition where the brain's surface appears smooth due to the absence of normal convolutions (gyri) and sulci. This occurs because the nerve cells fail to migrate properly during fetal development, resulting in a thickened cortex with disorganized layers of neurons.
Subcortical band heterotopia, also known as "double cortex syndrome," is a condition where there are abnormal clusters of nerve cells located between the cortex and the white matter of the brain. These clusters form a band-like structure beneath the cerebral cortex, hence the name "subcortical."
Both classical lissencephaly and subcortical band heterotopia can result in varying degrees of intellectual disability, developmental delay, seizures, motor impairment, and visual abnormalities. The severity of these symptoms depends on the extent and location of the brain abnormalities.
These conditions are typically caused by genetic mutations that affect genes involved in neuronal migration during fetal development. In some cases, they can be inherited from parents or occur spontaneously due to new mutations.
Epilepsy is a chronic neurological disorder characterized by recurrent, unprovoked seizures. These seizures are caused by abnormal electrical activity in the brain, which can result in a wide range of symptoms, including convulsions, loss of consciousness, and altered sensations or behaviors. Epilepsy can have many different causes, including genetic factors, brain injury, infection, or stroke. In some cases, the cause may be unknown.
There are many different types of seizures that can occur in people with epilepsy, and the specific type of seizure will depend on the location and extent of the abnormal electrical activity in the brain. Some people may experience only one type of seizure, while others may have several different types. Seizures can vary in frequency, from a few per year to dozens or even hundreds per day.
Epilepsy is typically diagnosed based on the patient's history of recurrent seizures and the results of an electroencephalogram (EEG), which measures the electrical activity in the brain. Imaging tests such as MRI or CT scans may also be used to help identify any structural abnormalities in the brain that may be contributing to the seizures.
While there is no cure for epilepsy, it can often be effectively managed with medication. In some cases, surgery may be recommended to remove the area of the brain responsible for the seizures. With proper treatment and management, many people with epilepsy are able to lead normal, productive lives.
Neuronal migration disorders (NMDs) are a group of genetic conditions that affect the development and migration of neurons (nerve cells) in the brain during embryonic development. These disorders result from abnormalities in the genetic code that control the movement and organization of neurons as they migrate to their proper positions in the brain.
NMDs can cause a wide range of neurological symptoms, depending on which areas of the brain are affected and the severity of the disorder. Symptoms may include intellectual disability, developmental delay, seizures, motor abnormalities, vision or hearing problems, and behavioral issues. Some NMDs may also be associated with structural brain abnormalities that can be seen on imaging studies.
Examples of neuronal migration disorders include lissencephaly, pachygyria, heterotopias, and agyria. These conditions are typically diagnosed through a combination of clinical evaluation, genetic testing, and neuroimaging studies. Treatment for NMDs is generally supportive and may involve medications, therapies, and surgical interventions to manage symptoms and improve quality of life.