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Polyneuropathy
Polyneuropathy ( poly- + neuro- + -pathy) is damage or disease affecting peripheral nerves (peripheral neuropathy) in roughly the same areas on both sides of the body, featuring weakness, numbness, and burning pain. It usually begins in the hands and feet and may progress to the arms and legs and sometimes to other parts of the body where it may affect the autonomic nervous system. It may be acute or chronic. A number of different disorders may cause polyneuropathy, including diabetes and some types of Guillain–Barré syndrome. Classification Polyneuropathies may be classified in different ways, such as by ''cause'', by ''presentation'', or by ''classes'' of polyneuropathy, in terms of which part of the nerve cell is affected mainly: the axon, the myelin sheath, or the cell body. * ''Distal axonopathy'', is the result of interrupted function of the peripheral nerves. It is the most common response of neurons to metabolic or toxic disturbances, and may be caused by metabolic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peripheral Neuropathy
Peripheral neuropathy, often shortened to neuropathy, is a general term describing disease affecting the peripheral nerves, meaning nerves beyond the brain and spinal cord. Damage to peripheral nerves may impair sensation, movement, gland, or organ function depending on which nerves are affected; in other words, neuropathy affecting motor, sensory, or autonomic nerves result in different symptoms. More than one type of nerve may be affected simultaneously. Peripheral neuropathy may be acute (with sudden onset, rapid progress) or chronic (symptoms begin subtly and progress slowly), and may be reversible or permanent. Common causes include systemic diseases (such as diabetes or leprosy), hyperglycemia-induced glycation, vitamin deficiency, medication (e.g., chemotherapy, or commonly prescribed antibiotics including metronidazole and the fluoroquinolone class of antibiotics (such as ciprofloxacin, levofloxacin, moxifloxacin)), traumatic injury, ischemia, radiation therapy, excessi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chronic Inflammatory Demyelinating Polyneuropathy
Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired autoimmune disease of the peripheral nervous system characterized by progressive weakness and impaired sensory function in the legs and arms. The disorder is sometimes called chronic relapsing polyneuropathy (CRP) or chronic inflammatory demyelinating polyradiculoneuropathy (because it involves the nerve roots). CIDP is closely related to Guillain–Barré syndrome and it is considered the chronic counterpart of that acute disease. Its symptoms are also similar to progressive inflammatory neuropathy. It is one of several types of neuropathy. Types Several variants have been reported. Specially important are: * An asymmetrical variant of CIDP is known as Lewis-Sumner Syndrome. or MADSAM (multifocal acquired demyelinating sensory and motor neuropathy) * A variant with CNS involvement named combined central and peripheral demyelination (CCPD) Currently there is one special variant in which the CNS is also affect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guillain–Barré Syndrome
Guillain–Barré syndrome (GBS) is a rapid-onset muscle weakness caused by the immune system damaging the peripheral nervous system. Typically, both sides of the body are involved, and the initial symptoms are changes in sensation or pain often in the back along with muscle weakness, beginning in the feet and hands, often spreading to the arms and upper body. The symptoms may develop over hours to a few weeks. During the acute phase, the disorder can be life-threatening, with about 15% of people developing weakness of the breathing muscles and, therefore, requiring mechanical ventilation. Some are affected by changes in the function of the autonomic nervous system, which can lead to dangerous abnormalities in heart rate and blood pressure. Although the cause is unknown, the underlying mechanism involves an autoimmune disorder in which the body's immune system mistakenly attacks the peripheral nerves and damages their myelin insulation. Sometimes this immune dysfunction is trig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diabetic Neuropathy
Diabetic neuropathy is various types of nerve damage associated with diabetes mellitus. Symptoms depend on the site of nerve damage and can include motor changes such as weakness; sensory symptoms such as numbness, tingling, or pain; or autonomic changes such as urinary symptoms. These changes are thought to result from microvascular injury involving small blood vessels that supply nerves (vasa nervorum). Relatively common conditions which may be associated with diabetic neuropathy include distal symmetric polyneuropathy; third, fourth, or sixth cranial nerve palsy; mononeuropathy; mononeuropathy multiplex; diabetic amyotrophy; and autonomic neuropathy. Signs and symptoms Diabetic neuropathy can affect any peripheral nerves including sensory neurons, motor neurons, and the autonomic nervous system. Therefore, diabetic neuropathy has the potential to affect essentially any organ system and can cause a range of symptoms. There are several distinct syndromes based on the organ syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schwann Cells
Schwann cells or neurolemmocytes (named after German physiologist Theodor Schwann) are the principal glia of the peripheral nervous system (PNS). Glial cells function to support neurons and in the PNS, also include satellite cells, olfactory ensheathing cells, enteric glia and glia that reside at sensory nerve endings, such as the Pacinian corpuscle. The two types of Schwann cells are myelinating and nonmyelinating. Myelinating Schwann cells wrap around axons of motor and sensory neurons to form the myelin sheath. The Schwann cell promoter is present in the downstream region of the human dystrophin gene that gives shortened transcript that are again synthesized in a tissue-specific manner. During the development of the PNS, the regulatory mechanisms of myelination are controlled by feedforward interaction of specific genes, influencing transcriptional cascades and shaping the morphology of the myelinated nerve fibers. Schwann cells are involved in many important aspects of peri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myelin
Myelin is a lipid-rich material that surrounds nerve cell axons (the nervous system's "wires") to insulate them and increase the rate at which electrical impulses (called action potentials) are passed along the axon. The myelinated axon can be likened to an electrical wire (the axon) with insulating material (myelin) around it. However, unlike the plastic covering on an electrical wire, myelin does not form a single long sheath over the entire length of the axon. Rather, myelin sheaths the nerve in segments: in general, each axon is encased with multiple long myelinated sections with short gaps in between called nodes of Ranvier. Myelin is formed in the central nervous system (CNS; brain, spinal cord and optic nerve) by glial cells called oligodendrocytes and in the peripheral nervous system (PNS) by glial cells called Schwann cells. In the CNS, axons carry electrical signals from one nerve cell body to another. In the PNS, axons carry signals to muscles and glands or from senso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcoholism
Alcoholism is, broadly, any drinking of alcohol (drug), alcohol that results in significant Mental health, mental or physical health problems. Because there is disagreement on the definition of the word ''alcoholism'', it is not a recognized diagnostic entity. Predominant diagnostic classifications are alcohol use disorder (DSM-5) or alcohol dependence (ICD-11); these are defined in their respective sources. Excessive alcohol use can damage all organ systems, but it particularly affects the brain, heart, liver, pancreas and immune system. Alcoholism can result in mental illness, delirium tremens, Wernicke–Korsakoff syndrome, Heart arrhythmia, irregular heartbeat, an impaired immune response, liver cirrhosis and alcohol and cancer, increased cancer risk. Drinking during pregnancy can result in fetal alcohol spectrum disorders. Women are generally more sensitive than men to the harmful effects of alcohol, primarily due to their smaller body weight, lower capacity to metaboli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcohol Use Disorder
Alcoholism is, broadly, any drinking of alcohol that results in significant mental or physical health problems. Because there is disagreement on the definition of the word ''alcoholism'', it is not a recognized diagnostic entity. Predominant diagnostic classifications are alcohol use disorder (DSM-5) or alcohol dependence (ICD-11); these are defined in their respective sources. Excessive alcohol use can damage all organ systems, but it particularly affects the brain, heart, liver, pancreas and immune system. Alcoholism can result in mental illness, delirium tremens, Wernicke–Korsakoff syndrome, irregular heartbeat, an impaired immune response, liver cirrhosis and increased cancer risk. Drinking during pregnancy can result in fetal alcohol spectrum disorders. Women are generally more sensitive than men to the harmful effects of alcohol, primarily due to their smaller body weight, lower capacity to metabolize alcohol, and higher proportion of body fat. In a small numbe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charcot–Marie–Tooth Disease
Charcot–Marie–Tooth disease (CMT) is a hereditary motor and sensory neuropathy of the peripheral nervous system characterized by progressive loss of muscle tissue and touch sensation across various parts of the body. This disease is the most commonly inherited neurological disorder, affecting about one in 2,500 people. It is named after those who classically described it: the Frenchman Jean-Martin Charcot (1825–1893), his pupil Pierre Marie (1853–1940), and the Briton Howard Henry Tooth (1856–1925). There is no known cure. Care focuses on maintaining function. CMT was previously classified as a subtype of muscular dystrophy. Signs and symptoms Symptoms of CMT usually begin in early childhood or early adulthood but can begin later. Some people do not experience symptoms until their early 30s or 40s. Usually, the initial symptom is foot drop early in the course of the disease. This can also cause hammertoe, where the toes are always curled. Wasting of muscle tissue of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motor Neurone Disease
Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND) or Lou Gehrig's disease, is a neurodegenerative disease that results in the progressive loss of motor neurons that control voluntary muscles. ALS is the most common type of motor neuron diseases. Early symptoms of ALS include stiff muscles, muscle twitches, and gradual increasing weakness and muscle wasting. ''Limb-onset ALS'' begins with weakness in the arms or legs, while ''bulbar-onset ALS'' begins with difficulty speaking or swallowing. Half of the people with ALS develop at least mild difficulties with thinking and behavior, and about 15% develop frontotemporal dementia. Most people experience pain. The affected muscles are responsible for chewing food, speaking, and walking. Motor neuron loss continues until the ability to eat, speak, move, and finally the ability to breathe is lost. ALS eventually causes paralysis and early death, usually from respiratory failure. Most cases of ALS (abo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Action Potential
An action potential occurs when the membrane potential of a specific cell location rapidly rises and falls. This depolarization then causes adjacent locations to similarly depolarize. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and in some plant cells. Certain endocrine cells such as pancreatic beta cells, and certain cells of the anterior pituitary gland are also excitable cells. In neurons, action potentials play a central role in cell-cell communication by providing for—or with regard to saltatory conduction, assisting—the propagation of signals along the neuron's axon toward synaptic boutons situated at the ends of an axon; these signals can then connect with other neurons at synapses, or to motor cells or glands. In other types of cells, their main function is to activate intracellular processes. In muscle cells, for example, an action potential is the first step in the chain of events l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurapraxia
Neurapraxia is a disorder of the peripheral nervous system in which there is a temporary loss of motor and sensory function due to blockage of nerve conduction, usually lasting an average of six to eight weeks before full recovery. Neurapraxia is derived from the word apraxia, meaning “loss or impairment of the ability to execute complex coordinated movements without muscular or sensory impairment”. This condition is typically caused by a blunt neural injury due to external blows or shock-like injuries to muscle fibers and skeletal nerve fibers, which leads to repeated or prolonged pressure buildup on the nerve. As a result of this pressure, ischemia occurs, a neural lesion results, and the human body naturally responds with edema extending in all directions from the source of the pressure. This lesion causes a complete or partial action potential conduction block over a segment of a nerve fiber and thus a reduction or loss of function in parts of the neural connection downst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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