Polyneuropathies
Peripheral Nervous System Diseases
Diagnostic Techniques, Neurological
Polyradiculoneuropathy
Alcoholic Neuropathy
Electrodiagnosis
Guillain-Barre Syndrome
Diabetic Neuropathies
Neural Conduction
Demyelinating Diseases
Leukoencephalopathy in multiple myeloma: two case reports. (1/283)
BACKGROUND: No case of leukoencephalopathy has been reported associated with multiple myeloma. PATIENTS: We report on two patients with a very rare association of leukoencephalopathy and multiple myeloma revealed by cognitive impairment. RESULTS: Chemotherapy has improved neurological and biological signs. Radiological abnormalities have been stabilized. CONCLUSION: The authors suggest that leukoencephalopathy is probably a direct cerebral expression of malignant gammopathy. (+info)Neurobehavioural effects of occupational exposure to cadmium: a cross sectional epidemiological study. (2/283)
BACKGROUND: A patient with unexplained minor behavioural changes associated with an axonal sensorimotor polyneuropathy had a history of chronic occupational exposure to cadmium (Cd). Although animal studies have shown that Cd is a potent neurotoxicant, little is known about its toxicity for the human central nervous system. The aim of this study was to investigate the toxic potential of chronic occupational exposure to Cd on neurobehavioural functions. METHODS: A cross sectional epidemiological study was conducted ina group of Cd workers and an age matched control group. Eighty nine adult men (42 exposed to Cd and 47 control workers) were given a blinded standardised examination that consisted of computer assisted neurobehavioural tests (neurobehavioural examination system), a validated questionnaire to assess neurotoxic complaints (neurotoxicity symptom checklist--60, NSC-60), and a standardised self administered questionnaire to detect complaints consistent with peripheral neuropathy and dysfunction of the autonomic nervous system. Historical and current data on biomonitoring of exposure to Cd, either the highest value of Cd in urine (CdU in microgram Cd/g creatinine) of each Cd worker during work (CdUmax) or the current value (CdUcurrent) of each control, were available as well as data on microproteinuria. RESULTS: Cd workers (CdUmax: mean (range), 12.6 (0.4-38.4)) performed worse than the controls (CdUcurrent: mean (range), 0.7 (0.1-2.0)) on visuomotor tasks, symbol digit substitution (p = 0.008), and simple reaction time to direction (p = 0.058) or location (p = 0.042) of a stimulus. In multiple linear regression analysis, symbol digit substitution, simple direction reaction time test, and simple location reaction time test were significantly related to CdUmax, (beta = 0.35 (p < 0.001), beta = 0.25 (p = 0.012), and beta = 0.23 (p = 0.021) respectively). More complaints consistent with peripheral neuropathy (p = 0.004), complaints about equilibrium (p = 0.015), and complaints about concentration ability (p = 0.053) were found in the group exposed to Cd than in the control group, and these variables correlated positively with CdUmax (peripheral neuropathy: beta = 0.38, p < 0.001; equilibrium: beta = 0.22, p = 0.057; concentration ability: beta = 0.27, p = 0.020). CONCLUSION: Slowing of visuomotor functioning on neurobehavioural testing and increase in complaints consistent with peripheral neuropathy, complaints about equilibrium, and complaints about concentration ability were dose dependently associated with CdU. Age, exposure to other neurotoxicants, or status of renal function could not explain these findings. The present study also indicates that an excess of complaints may be detected in Cd workers before signs of microproteinuria induced by Cd occur. (+info)Asymptomatic electrophysiologic carpal tunnel syndrome in diabetics: entrapment or polyneuropathy. (3/283)
Electrophysiologic carpal tunnel syndrome (CTS) is common and is frequently asymptomatic in diabetics. In order to evaluate the clinical significance of asymptomatic electrophysiologic CTS, the nerve conduction studies (NCS) of 48 diabetics with asymptomatic electrophysiologic CTS were compared with those of 56 age and gender-matched controls, as well as 50 patients with symptomatic CTS without diabetes. Nerve conduction velocities of the ulnar, peroneal, and posterior tibial nerves were significantly slower in diabetics with asymptomatic electrophysiologic CTS than in normal controls. Compared to symptomatic non-diabetic CTS, there was also significant slowing of the median and ulnar nerve conduction velocities in asymptomatic diabetic CTS. However, in diabetics with asymptomatic CTS, abnormalities of the distal segment of the median NCS were more prominent compared with those of all the other tested nerves. These findings suggested that asymptomatic electrophysiologic CTS in diabetics is a manifestation of increased vulnerability to the entrapment of the peripheral nerve. (+info)Enhancement of AA-amyloid formation in mice by transthyretin amyloid fragments and polyethylene glycol. (4/283)
The mechanism behind amyloid formation is unknown in all types of amyloidosis. Several substances can enhance amyloid formation in animal experiments. To induce secondary systemic amyloid (AA-type amyloid) formation, we injected silver nitrate into mice together with either amyloid fibrils obtained from patients with familial polyneuropathy (FAP) type I or polyethylene glycol (PEG). Mice injected with silver nitrate only served as controls. Amyloid deposits were detectable at day 3 in animals injected with amyloid fibrils and in those injected with PEG, whereas in control mice, deposits were not noted before day 12. Our results indicate that amyloid fibrils from FAP patients and even a non-sulfate containing polysaccharide (PEG) have the potential to act as amyloid-enhancing factors. (+info)Abeta fibers mediate cutaneous reflexes during human walking. (5/283)
During human gait, transmission of cutaneous reflexes from the foot is controlled specifically according to the phase of the step cycle. These reflex responses can be evoked by nonnociceptive stimuli, and therefore it is thought that the large-myelinated and low-threshold Abeta afferent fibers mediate these reflexes. At present, this hypothesis is not yet verified. To test whether Abeta fibers are involved the reflex responses were studied in patients with a sensory polyneuropathy who suffer from a predominant loss of large-myelinated Abeta fibers. The sural nerve of both patients and healthy control subjects was stimulated electrically at a nonnociceptive intensity during the early and late swing phases while they walked on a treadmill. The responses were studied by recording electromyographic (EMG) activity of the biceps femoris (BF) and tibialis anterior (TA) of the stimulated leg. In both phases, large facilitatory responses were observed in the BF of the healthy subjects. These facilitations were reduced significantly in the BF of the patients, indicating that Abeta fibers mediate these reflexes. In TA similar results were obtained. The absolute response magnitude across the two phases was significantly smaller for the patients than for the healthy subjects. The TA responses for the healthy subjects were on average facilitatory during early swing and suppressive during end swing. Both facilitations and suppressions were considerably smaller for the patients, indicating that both types of responses are mediated by Abeta fibers. It is concluded that low-threshold Abeta sensory fibers mediate these reflexes during human gait. The low threshold and the precise phase-dependent control of these responses suggest that these responses are important in the regulation of gait. The loss of such reflex activity may be related to the gait impairments of these patients. (+info)Diabetic neuropathy examination: a hierarchical scoring system to diagnose distal polyneuropathy in diabetes. (6/283)
OBJECTIVE: Existing physical examination scoring systems for distal diabetic polyneuropathy (PNP) do not fulfill all of the following criteria: validity, manageability, predictive value, and hierarchy The aim of this study was to adapt the Neuropathy Disability Score (NDS) to diagnose PNP in diabetes so that it fulfills these criteria. RESEARCH DESIGN AND METHODS: A total of 73 patients with diabetes were examined with the NDS. Monofilaments and biothesiometry were used as clinical standards for PNP to modify the NDS. RESULTS: A total of 43 men and 30 women were studied; mean duration of diabetes was 15 years (1-43), and mean age was 57 years (19-90). A total of 24 patients had type 1 diabetes, and 49 patients had type 2 diabetes. Clinically relevant items were selected from the original 35 NDS items (specific item scored positive in >3 patients). The resulting 8-item Diabetic Neuropathy Examination (DNE) score could accurately predict the results of the clinical standards and is strongly hierarchical (H value 0.53). The sensitivity and specificity of the DNE at a cut-off level of 3 to 4 were 0.96 and 0.51 for abnormal monofilament scores, respectively. For abnormal vibration perception threshold scores, these values were 0.97 and 0.59, respectively. Reproducibility as assessed by inter- and intrarater agreement was good. CONCLUSIONS: The DNE is a sensitive and well-validated hierarchical scoring system that is fast and easy to perform in clinical practice. (+info)4'-Iodo-4'-deoxydoxorubicin disrupts the fibrillar structure of transthyretin amyloid. (7/283)
Transthyretin (TTR) is a tetrameric protein synthesized mainly by the liver and the choroid plexus, from where it is secreted into the plasma and the cerebrospinal fluid, respectively. Some forms of polyneuropathy, vitreopathy, and cardiomyopathy are caused by the deposition of normal and/or mutant TTR molecules in the form of amyloid fibrils. Familial amyloidotic polyneuropathy is the most common form of TTR amyloidosis related to the V30M variant. It is still unclear the process by which soluble proteins deposit as amyloid. The treatment of amyloid-related disorders might attempt the stabilization of the soluble protein precursor to retard or inhibit its deposition as amyloid; or aim at the resorption of the deposited amyloid. The anthracycline 4'-iodo-4'-deoxydoxorubicin (I-DOX) has been shown to reduce the amyloid load in immunoglobulin light-chain amyloidosis. We investigated 1) whether I-DOX has affinity for TTR amyloid in tissues, 2) determined the I-DOX binding constants to TTR synthetic fibrils, and 3) determined the nature of the effect of I-DOX on TTR fibrils. We report that 1) I-DOX co-localizes with amyloid deposits in tissue sections of patients with familial amyloidotic polyneuropathy; 2) I-DOX strongly interacts with TTR amyloid fibrils and presents two binding sites with k(d) of 1.5 x 10(-11) mol/L and 5.6 x 10(-10) mol/L, respectively; and 3) I-DOX disrupts the fibrillar structure of TTR amyloid into amorphous material, as assessed by electron microscopy but does not solubilize the fibrils as confirmed by filter assays. These data support the hypothesis that I-DOX and less toxic derivatives can prove efficient in the treatment of TTR-related amyloidosis. (+info)Persistence of tropical ataxic neuropathy in a Nigerian community. (8/283)
OBJECTIVES: The term tropical ataxic neuropathy (TAN) is currently used to describe several neurological syndromes attributed to toxiconutritional causes. However, TAN was initially proposed to describe a specific neurological syndrome seen predominantly among the Ijebu speaking Yorubas in south western Nigeria. In this study, the prevalence of TAN was determined in Ososa, a semiurban community in south western Nigeria described as endemic for TAN in 1969, and its neurological features were compared with Strachan's syndrome, prisoners of war neuropathy, the epidemic neuropathy in Cuba, and konzo. METHODS: A census of Ososa was followed by door to door screening of all subjects aged 10 years and above with a newly designed screening instrument. Subjects who screened positive had a neurological examination, and the diagnosis of TAN was made if any two or more of bilateral optic atrophy, bilateral neurosensory deafness, sensory gait ataxia, or distal symmetric sensory polyneuropathy were present. RESULTS: A total of 4583 inhabitants were registered in the census. Of these, 3428 subjects aged 10 years and above were screened. The diagnosis of TAN was made in 206 of 323 subjects who screened positive for TAN. The prevalence of TAN was 6. 0%, 3.9% in males and 7.7% in females. The highest age specific prevalence was 24% in the 60-69 years age group in women. CONCLUSION: The occurrence of TAN in Ososa continues at a higher prevalence than was reported 30 years ago. Its neurological features and natural history do not resemble those described for Strachan syndrome, epidemic neuropathy in Cuba, or konzo. The increasing consumption of cassava foods linked to its causation makes TAN of public health importance in Nigeria, the most populous African country. (+info)Polyneuropathy is a medical condition that refers to the damage or dysfunction of peripheral nerves (nerves outside the brain and spinal cord) in multiple areas of the body. These nerves are responsible for transmitting sensory, motor, and autonomic signals between the central nervous system and the rest of the body.
In polyneuropathies, this communication is disrupted, leading to various symptoms depending on the type and extent of nerve damage. Commonly reported symptoms include:
1. Numbness or tingling in the hands and feet
2. Muscle weakness and cramps
3. Loss of reflexes
4. Burning or stabbing pain
5. Balance and coordination issues
6. Increased sensitivity to touch
7. Autonomic dysfunction, such as bowel, bladder, or digestive problems, and changes in blood pressure
Polyneuropathies can be caused by various factors, including diabetes, alcohol abuse, nutritional deficiencies, autoimmune disorders, infections, toxins, inherited genetic conditions, or idiopathic (unknown) causes. The treatment for polyneuropathy depends on the underlying cause and may involve managing underlying medical conditions, physical therapy, pain management, and lifestyle modifications.
Peripheral Nervous System (PNS) diseases, also known as Peripheral Neuropathies, refer to conditions that affect the functioning of the peripheral nervous system, which includes all the nerves outside the brain and spinal cord. These nerves transmit signals between the central nervous system (CNS) and the rest of the body, controlling sensations, movements, and automatic functions such as heart rate and digestion.
PNS diseases can be caused by various factors, including genetics, infections, toxins, metabolic disorders, trauma, or autoimmune conditions. The symptoms of PNS diseases depend on the type and extent of nerve damage but often include:
1. Numbness, tingling, or pain in the hands and feet
2. Muscle weakness or cramps
3. Loss of reflexes
4. Decreased sensation to touch, temperature, or vibration
5. Coordination problems and difficulty with balance
6. Sexual dysfunction
7. Digestive issues, such as constipation or diarrhea
8. Dizziness or fainting due to changes in blood pressure
Examples of PNS diseases include Guillain-Barre syndrome, Charcot-Marie-Tooth disease, diabetic neuropathy, and peripheral nerve injuries. Treatment for these conditions varies depending on the underlying cause but may involve medications, physical therapy, lifestyle changes, or surgery.
Neurological diagnostic techniques are medical tests and examinations used to identify and diagnose conditions related to the nervous system, which includes the brain, spinal cord, nerves, and muscles. These techniques can be divided into several categories:
1. Clinical Examination: A thorough physical examination, including a neurological evaluation, is often the first step in diagnosing neurological conditions. This may involve assessing a person's mental status, muscle strength, coordination, reflexes, sensation, and gait.
2. Imaging Techniques: These are used to produce detailed images of the brain and nervous system. Common imaging techniques include:
- Computed Tomography (CT): This uses X-rays to create cross-sectional images of the brain and other parts of the body.
- Magnetic Resonance Imaging (MRI): This uses a strong magnetic field and radio waves to produce detailed images of the brain and other internal structures.
- Functional MRI (fMRI): This is a type of MRI that measures brain activity by detecting changes in blood flow.
- Positron Emission Tomography (PET): This uses small amounts of radioactive material to produce detailed images of brain function.
- Single Photon Emission Computed Tomography (SPECT): This is a type of nuclear medicine imaging that uses a gamma camera and a computer to produce detailed images of brain function.
3. Electrophysiological Tests: These are used to measure the electrical activity of the brain and nervous system. Common electrophysiological tests include:
- Electroencephalography (EEG): This measures the electrical activity of the brain.
- Evoked Potentials (EPs): These measure the electrical response of the brain and nervous system to sensory stimuli, such as sound or light.
- Nerve Conduction Studies (NCS): These measure the speed and strength of nerve impulses.
- Electromyography (EMG): This measures the electrical activity of muscles.
4. Laboratory Tests: These are used to analyze blood, cerebrospinal fluid, and other bodily fluids for signs of neurological conditions. Common laboratory tests include:
- Complete Blood Count (CBC): This measures the number and type of white and red blood cells in the body.
- Blood Chemistry Tests: These measure the levels of various chemicals in the blood.
- Lumbar Puncture (Spinal Tap): This is used to collect cerebrospinal fluid for analysis.
- Genetic Testing: This is used to identify genetic mutations associated with neurological conditions.
5. Imaging Studies: These are used to produce detailed images of the brain and nervous system. Common imaging studies include:
- Magnetic Resonance Imaging (MRI): This uses a strong magnetic field and radio waves to produce detailed images of the brain and nervous system.
- Computed Tomography (CT): This uses X-rays to produce detailed images of the brain and nervous system.
- Functional MRI (fMRI): This measures changes in blood flow in the brain during cognitive tasks.
- Diffusion Tensor Imaging (DTI): This is used to assess white matter integrity in the brain.
- Magnetic Resonance Spectroscopy (MRS): This is used to measure chemical levels in the brain.
Polyradiculoneuropathy is a medical term that refers to a condition affecting multiple nerve roots and peripheral nerves. It's a type of neuropathy, which is damage or disease affecting the peripheral nerves, and it involves damage to the nerve roots as they exit the spinal cord.
The term "poly" means many, "radiculo" refers to the nerve root, and "neuropathy" indicates a disorder of the nerves. Therefore, polyradiculoneuropathy implies that multiple nerve roots and peripheral nerves are affected.
This condition can result from various causes, such as infections (like Guillain-Barre syndrome), autoimmune disorders (such as lupus or rheumatoid arthritis), diabetes, cancer, or exposure to toxins. Symptoms may include weakness, numbness, tingling, or pain in the limbs, which can progress and become severe over time. Proper diagnosis and management are crucial for improving outcomes and preventing further nerve damage.
Alcoholic neuropathy is a type of nerve damage that occurs due to excessive alcohol consumption. It's caused by the toxic effects of alcohol and its byproducts on nerves throughout the body, particularly in the peripheral nervous system. The condition typically develops over time, with symptoms becoming more severe as alcohol abuse continues.
The symptoms of alcoholic neuropathy can vary widely depending on which nerves are affected. However, common symptoms include:
1. Numbness or tingling in the arms and legs
2. Muscle weakness and cramps
3. Loss of reflexes
4. Difficulty with balance and coordination
5. Pain or burning sensations in the extremities
6. Heat intolerance
7. Bladder and bowel dysfunction
8. Sexual dysfunction
Treatment for alcoholic neuropathy typically involves addressing the underlying alcohol abuse, as well as managing symptoms with medications and physical therapy. In severe cases, hospitalization may be necessary to monitor and manage complications. It's important to note that abstaining from alcohol is the only way to prevent further nerve damage and improve symptoms over time.
Electrodiagnosis, also known as electromyography (EMG), is a medical diagnostic procedure that evaluates the health and function of muscles and nerves. It measures the electrical activity of skeletal muscles at rest and during contraction, as well as the conduction of electrical signals along nerves.
The test involves inserting a thin needle electrode into the muscle to record its electrical activity. The physician will ask the patient to contract and relax the muscle while the electrical activity is recorded. The resulting data can help diagnose various neuromuscular disorders, such as nerve damage or muscle diseases, by identifying abnormalities in the electrical signals.
Electrodiagnosis can be used to diagnose conditions such as carpal tunnel syndrome, peripheral neuropathy, muscular dystrophy, and amyotrophic lateral sclerosis (ALS), among others. It is a valuable tool in the diagnosis and management of neuromuscular disorders, helping physicians to develop appropriate treatment plans for their patients.
Guillain-Barré syndrome (GBS) is a rare autoimmune disorder in which the body's immune system mistakenly attacks the peripheral nervous system, leading to muscle weakness, tingling sensations, and sometimes paralysis. The peripheral nervous system includes the nerves that control our movements and transmit signals from our skin, muscles, and joints to our brain.
The onset of GBS usually occurs after a viral or bacterial infection, such as respiratory or gastrointestinal infections, or following surgery, vaccinations, or other immune system triggers. The exact cause of the immune response that leads to GBS is not fully understood.
GBS typically progresses rapidly over days or weeks, with symptoms reaching their peak within 2-4 weeks after onset. Most people with GBS experience muscle weakness that starts in the lower limbs and spreads upward to the upper body, arms, and face. In severe cases, the diaphragm and chest muscles may become weakened, leading to difficulty breathing and requiring mechanical ventilation.
The diagnosis of GBS is based on clinical symptoms, nerve conduction studies, and sometimes cerebrospinal fluid analysis. Treatment typically involves supportive care, such as pain management, physical therapy, and respiratory support if necessary. In addition, plasma exchange (plasmapheresis) or intravenous immunoglobulin (IVIG) may be used to reduce the severity of symptoms and speed up recovery.
While most people with GBS recover completely or with minimal residual symptoms, some may experience long-term disability or require ongoing medical care. The prognosis for GBS varies depending on the severity of the illness and the individual's age and overall health.
Diabetic neuropathies refer to a group of nerve disorders that are caused by diabetes. High blood sugar levels can injure nerves throughout the body, but diabetic neuropathies most commonly affect the nerves in the legs and feet.
There are four main types of diabetic neuropathies:
1. Peripheral neuropathy: This is the most common type of diabetic neuropathy. It affects the nerves in the legs and feet, causing symptoms such as numbness, tingling, burning, or shooting pain.
2. Autonomic neuropathy: This type of neuropathy affects the autonomic nerves, which control involuntary functions such as heart rate, blood pressure, digestion, and bladder function. Symptoms may include dizziness, fainting, digestive problems, sexual dysfunction, and difficulty regulating body temperature.
3. Proximal neuropathy: Also known as diabetic amyotrophy, this type of neuropathy affects the nerves in the hips, thighs, or buttocks, causing weakness, pain, and difficulty walking.
4. Focal neuropathy: This type of neuropathy affects a single nerve or group of nerves, causing symptoms such as weakness, numbness, or pain in the affected area. Focal neuropathies can occur anywhere in the body, but they are most common in the head, torso, and legs.
The risk of developing diabetic neuropathies increases with the duration of diabetes and poor blood sugar control. Other factors that may contribute to the development of diabetic neuropathies include genetics, age, smoking, and alcohol consumption.
Neural conduction is the process by which electrical signals, known as action potentials, are transmitted along the axon of a neuron (nerve cell) to transmit information between different parts of the nervous system. This electrical impulse is generated by the movement of ions across the neuronal membrane, and it propagates down the length of the axon until it reaches the synapse, where it can then stimulate the release of neurotransmitters to communicate with other neurons or target cells. The speed of neural conduction can vary depending on factors such as the diameter of the axon, the presence of myelin sheaths (which act as insulation and allow for faster conduction), and the temperature of the environment.
Demyelinating diseases are a group of disorders that are characterized by damage to the myelin sheath, which is the protective covering surrounding nerve fibers in the brain, optic nerves, and spinal cord. Myelin is essential for the rapid transmission of nerve impulses, and its damage results in disrupted communication between the brain and other parts of the body.
The most common demyelinating disease is multiple sclerosis (MS), where the immune system mistakenly attacks the myelin sheath. Other demyelinating diseases include:
1. Acute Disseminated Encephalomyelitis (ADEM): An autoimmune disorder that typically follows a viral infection or vaccination, causing widespread inflammation and demyelination in the brain and spinal cord.
2. Neuromyelitis Optica (NMO) or Devic's Disease: A rare autoimmune disorder that primarily affects the optic nerves and spinal cord, leading to severe vision loss and motor disability.
3. Transverse Myelitis: Inflammation of the spinal cord causing damage to both sides of one level (segment) of the spinal cord, resulting in various neurological symptoms such as muscle weakness, numbness, or pain, depending on which part of the spinal cord is affected.
4. Guillain-Barré Syndrome: An autoimmune disorder that causes rapid-onset muscle weakness, often beginning in the legs and spreading to the upper body, including the face and breathing muscles. It occurs when the immune system attacks the peripheral nerves' myelin sheath.
5. Central Pontine Myelinolysis (CPM): A rare neurological disorder caused by rapid shifts in sodium levels in the blood, leading to damage to the myelin sheath in a specific area of the brainstem called the pons.
These diseases can result in various symptoms, such as muscle weakness, numbness, vision loss, difficulty with balance and coordination, and cognitive impairment, depending on the location and extent of the demyelination. Treatment typically focuses on managing symptoms, modifying the immune system's response, and promoting nerve regeneration and remyelination when possible.
Immunoglobulin M (IgM) is a type of antibody that is primarily found in the blood and lymph fluid. It is the first antibody to be produced in response to an initial exposure to an antigen, making it an important part of the body's primary immune response. IgM antibodies are large molecules that are composed of five basic units, giving them a pentameric structure. They are primarily found on the surface of B cells as membrane-bound immunoglobulins (mlgM), where they function as receptors for antigens. Once an mlgM receptor binds to an antigen, it triggers the activation and differentiation of the B cell into a plasma cell that produces and secretes large amounts of soluble IgM antibodies.
IgM antibodies are particularly effective at agglutination (clumping) and complement activation, which makes them important in the early stages of an immune response to help clear pathogens from the bloodstream. However, they are not as stable or long-lived as other types of antibodies, such as IgG, and their levels tend to decline after the initial immune response has occurred.
In summary, Immunoglobulin M (IgM) is a type of antibody that plays a crucial role in the primary immune response to antigens by agglutination and complement activation. It is primarily found in the blood and lymph fluid, and it is produced by B cells after they are activated by an antigen.