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". ...

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

brain The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head ( cephalization), usually near organs for special ...

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 distributi ...

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 (''mul ...

* Toxic leukoencephalopathy * Leukoencephalopathy with vanishing white matter * Leukoencephalopathy with neuroaxonal spheroids * Reversible posterior leukoencephalopathy syndrome * Megalencephalic leukoencephalopathy with subcortical cysts. It can also refer to gene MLC1 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 diseases are classified according to their underlying causes into five groups: noninfectious–inflammatory, infectious–inflammatory, toxic–metabolic, hypoxic–ischemic (vascular problems like Binswanger's disease), 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 is at the same time hereditary and hypoxic.

References

{{reflist Brain disorders