Leukoencephalopathy (

leukodystrophy Leukodystrophies are a group of usually inherited disorders characterized by degeneration of the white matter in the brain. The word ''leukodystrophy'' comes from the Greek roots ''leuko'', "white", ''dys'', "abnormal" and ''troph'', "growth". Th ...

-like diseases) is a term that describes all of the

brain A brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as Visual perception, vision. I ...

white matter White matter refers to areas of the central nervous system (CNS) that are mainly made up of myelinated axons, also called tracts. Long thought to be passive tissue, white matter affects learning and brain functions, modulating the distribu ...

diseases, whether their molecular cause is known or unknown. It can refer specifically to any of these diseases: *

Progressive multifocal leukoencephalopathy Progressive multifocal leukoencephalopathy (PML) is a rare and often fatal viral disease characterized by progressive damage (''-pathy'') or inflammation of the white matter (''leuko-'') of the brain (''-encephalo-'') at multiple locations (''mu ...

* Toxic leukoencephalopathy *

Leukoencephalopathy with vanishing white matter Leukoencephalopathy with vanishing white matter (VWM disease) is an autosomal recessive neurological disease. The cause of the disease are mutations in any of the 5 genes encoding subunits of the translation initiation factor eIF2B: EIF2B1, EIF ...

Leukoencephalopathy with neuroaxonal spheroids Leukoencephalopathy with neuroaxonal spheroids (LENAS) is an extremely rare kind of leukoencephalopathy and is classified as a neurodegenerative disease. LENAS is a cause of severe and subacute dementia that results from damage to certain areas of ...

Reversible posterior leukoencephalopathy syndrome Posterior reversible encephalopathy syndrome (PRES), also known as reversible posterior leukoencephalopathy syndrome (RPLS), is a rare condition in which parts of the brain are affected by swelling, usually as a result of an underlying cause. Some ...

* Megalencephalic leukoencephalopathy with subcortical cysts. It can also refer to gene

MLC1 Membrane protein MLC1 is a protein that in humans is encoded by the ''MLC1'' gene. MLC1 (also called ''WKL1'') is the only human gene currently associated with megalencephalic leukoencephalopathy with subcortical cysts (MLC). Evidence exists fo ...

or Megalencephalic leukoencephalopathy with subcortical cysts 1, a human gene related to the former disease. *

Hypertensive leukoencephalopathy Hypertensive leukoencephalopathy refers to a degeneration of the white matter of the brain following a sudden increase in blood pressure.Blueprints Neurology, 2nd ed. Signs and symptoms Symptoms include sudden increase in blood pressure, acute c ...

The classification of leukoencephalopathies is a matter of debate. Some authors divide leukoencephalopathies into hereditary disorders and acquired disorders. The hereditary demyelinating disorders are then classified according to the localization of the underlying metabolic defect, and they include the leukodystrophies when myelin growth is the underlying problem. The acquired

demyelinating disease A demyelinating disease is any disease of the nervous system in which the myelin sheath of neurons is damaged. This damage impairs the conduction of signals in the affected nerves. In turn, the reduction in conduction ability causes deficiency i ...

s are classified according to their underlying causes into five groups: noninfectious–inflammatory, infectious–inflammatory, toxic–metabolic, hypoxic–ischemic (vascular problems like

Binswanger's disease Binswanger's disease, also known as subcortical leukoencephalopathy and subcortical arteriosclerotic encephalopathy, is a form of small-vessel vascular dementia caused by damage to the white brain matter. White matter atrophy can be caused by man ...

), and traumatic. Marjo S. van der Knaap and Jaap Valk, eds. New York: Springer; 2005, Magnetic Resonance of Myelination and Myelin Disorders, 3rd ed. This classification is diffuse sometimes. For example

CADASIL syndrome CADASIL or CADASIL syndrome, involving cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, is the most common form of hereditary stroke disorder, and is thought to be caused by mutations of the ''Notch 3'' ge ...

is at the same time hereditary and hypoxic.

References

{{reflist Brain disorders