Demyelinating disease
Encyclopedia
A demyelinating disease is any disease
of the nervous system
in which the myelin
sheath of neuron
s is damaged. This impairs the conduction of signals in the affected nerves, causing impairment in sensation, movement, cognition, or other functions depending on which nerves are involved.
The term describes the effect of the disease, rather than its cause; some demyelinating diseases are caused by genetics
, some by infectious
agents, some by autoimmune reactions, and some by unknown factors. Organophosphate
s, a class of chemicals which are the active ingredients in commercial insecticides such as sheep dip
, weed-killers
, and flea treatment preparations for pets, etc., will also demyelinate nerves.
Neuroleptics can cause demyelination.
include:
Demyelinating diseases of the peripheral nervous system
include:
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
of the nervous system
Nervous system
The nervous system is an organ system containing a network of specialized cells called neurons that coordinate the actions of an animal and transmit signals between different parts of its body. In most animals the nervous system consists of two parts, central and peripheral. The central nervous...
in which the myelin
Myelin
Myelin is a dielectric material that forms a layer, the myelin sheath, usually around only the axon of a neuron. It is essential for the proper functioning of the nervous system. Myelin is an outgrowth of a type of glial cell. The production of the myelin sheath is called myelination...
sheath of neuron
Neuron
A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...
s is damaged. This impairs the conduction of signals in the affected nerves, causing impairment in sensation, movement, cognition, or other functions depending on which nerves are involved.
The term describes the effect of the disease, rather than its cause; some demyelinating diseases are caused by genetics
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
, some by infectious
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
agents, some by autoimmune reactions, and some by unknown factors. Organophosphate
Organophosphate
An organophosphate is the general name for esters of phosphoric acid. Phosphates are probably the most pervasive organophosphorus compounds. Many of the most important biochemicals are organophosphates, including DNA and RNA as well as many cofactors that are essential for life...
s, a class of chemicals which are the active ingredients in commercial insecticides such as sheep dip
Sheep dip
Sheep dip is a liquid formulation of insecticide and fungicide which shepherds and farmers may use to protect their sheep from infestation against external parasites such as itch mite , blow-fly, ticks and lice...
, weed-killers
Herbicide
Herbicides, also commonly known as weedkillers, are pesticides used to kill unwanted plants. Selective herbicides kill specific targets while leaving the desired crop relatively unharmed. Some of these act by interfering with the growth of the weed and are often synthetic "imitations" of plant...
, and flea treatment preparations for pets, etc., will also demyelinate nerves.
Neuroleptics can cause demyelination.
Demyelinating diseases
Demyelinating diseases of the central nervous systemCentral nervous system
The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...
include:
- multiple sclerosisMultiple sclerosisMultiple sclerosis is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms...
(together with the similar diseases called idiopathic inflammatory demyelinating diseasesIdiopathic inflammatory demyelinating diseasesIdiopathic inflammatory demyelinating diseases , sometimes known as borderline forms of multiple sclerosis, is a collection of multiple sclerosis variants, sometimes considered different diseases, but considered by others to form a spectrum differing only in terms of chronicity, severity, and...
) - Vitamin B12 deficiencyVitamin B12 deficiencyVitamin B12 deficiency or hypocobalaminemia is a low blood level of vitamin B12, it can cause permanent damage to nervous tissue as a long term effect. Vitamin B12 was discovered from its relationship to the disease pernicious anemia, which is an autoimmune disease that destroys parietal cells in...
- Central pontine myelinolysisCentral pontine myelinolysisCentral pontine myelinolysis is neurological disease caused by severe damage of the myelin sheath of nerve cells in the brainstem, more precisely in the area termed the pons, predominately of iatrogenic etiology...
- Tabes DorsalisTabes dorsalisTabes dorsalis is a slow degeneration of the sensory neurons that carry afferent information. The degenerating nerves are in the dorsal columns of the spinal cord and carry information that help maintain a person's sense of position , vibration, and discriminative touch.-Cause:Tabes dorsalis is...
- transverse myelitisTransverse myelitisTransverse myelitis is a neurological disorder caused by an inflammatory process of the spinal cord, and can cause axonal demyelination. The name is derived from Greek referring to the "spinal cord", and the suffix -itis, which denotes inflammation...
- Devic's diseaseDevic's diseaseNeuromyelitis optica , also known as Devic's disease or Devic's syndrome, is an autoimmune, inflammatory disorder in which a person's own immune system attacks the optic nerves and spinal cord. This produces an inflammation of the optic nerve and the spinal cord...
- progressive multifocal leukoencephalopathyProgressive multifocal leukoencephalopathyProgressive multifocal leukoencephalopathy , also known as progressive multifocal leukoencephalitis, is a rare and usually fatal viral disease that is characterized by progressive damage or inflammation of the white matter of the brain at multiple locations .It occurs almost exclusively in...
- Optic neuritisOptic neuritisOptic neuritis is the inflammation of the optic nerve that may cause a complete or partial loss of vision.-Causes:The optic nerve comprises axons that emerge from the retina of the eye and carry visual information to the primary visual nuclei, most of which is relayed to the occipital cortex of the...
- LeukodystrophiesLeukodystrophyLeukodystrophy refers to a group of disorders characterized by dysfunction of the white matter of the brain. The leukodystrophies are caused by imperfect growth or development of the myelin sheath, the fatty covering that acts as an insulator around nerve fibers...
Demyelinating diseases of the peripheral nervous system
Peripheral nervous system
The peripheral nervous system consists of the nerves and ganglia outside of the brain and spinal cord. The main function of the PNS is to connect the central nervous system to the limbs and organs. Unlike the CNS, the PNS is not protected by the bone of spine and skull, or by the blood–brain...
include:
- Guillain-Barré syndromeGuillain-Barré syndromeGuillain–Barré syndrome , sometimes called Landry's paralysis, is an acute inflammatory demyelinating polyneuropathy , a disorder affecting the peripheral nervous system. Ascending paralysis, weakness beginning in the feet and hands and migrating towards the trunk, is the most typical symptom...
and its chronic counterpart, chronic inflammatory demyelinating polyneuropathyChronic inflammatory demyelinating polyneuropathyChronic inflammatory demyelinating polyneuropathy is an acquired immune-mediated inflammatory disorder of the peripheral nervous system. The disorder is sometimes called chronic relapsing polyneuropathy. CIDP is closely related to Guillain-Barré syndrome and it is considered the chronic... - anti-MAG peripheral neuropathyPeripheral neuropathyPeripheral neuropathy is the term for damage to nerves of the peripheral nervous system, which may be caused either by diseases of or trauma to the nerve or the side-effects of systemic illness....
- Charcot-Marie-Tooth DiseaseCharcot-Marie-Tooth diseaseCharcot–Marie–Tooth disease- , known also as Morbus Charcot-Marie-Tooth, Charcot-Marie-Tooth neuropathy, hereditary motor and sensory neuropathy , hereditary sensorimotor neuropathy , or peroneal muscular atrophy, is an inherited disorder of nerves that takes different forms...
- Copper deficiencyCopper deficiencyCopper deficiency is a very rare hematological and neurological disorder. The neurodegenerative syndrome of copper deficiency has been recognized for some time in ruminant animals, in which it is commonly known as "swayback" The disease involves a nutritional deficiency in the trace element copper...
See also
- Multiple sclerosis borderline
- The Lesion ProjectThe Lesion ProjectMultiple sclerosis is a condition in which the CNS of a person present a special kind of distributed lesions whose pathophysiology is complex and still under investigation. It is considered a pathological entity by some authors and a clinical entity by some others.Damage occurs in two phases...
(multiple sclerosis) - The Myelin ProjectThe Myelin ProjectThe Myelin Project is an international scientific research organization aimed at accelerating clinical and translational research focused on myelin repair and to regenerate the nerve's myelin sheath, — a process called remyelination — destroyed in a host of diseases such as multiple...
- Myelin Repair FoundationMyelin Repair FoundationThe Myelin Repair Foundation is a 5013 not-for-profit organization based in Saratoga, California. The organization applies a collaborative business model to the process of medical research with the aim of accelerating the identification and development of new patient treatments...