Canadian Medical Guide > Diseases > Nervous System Diseases > Demyelinating Diseases > Hereditary Central Nervous System Demyelinating Diseases Terms and Definitions




Hereditary Central Nervous System Demyelinating Diseases

Medical Definition: Inherited conditions characterized by a loss of myelin in the central nervous system.
Hereditary Central Nervous System Demyelinating Diseases Categories.
Canadian Medical Guide Definition Alexander Disease - A rare inherited disorder of myelin formation. Alexander disease is a progressive leukencephalopathy whose hallmark is the widespread accumulation of cytoplasmic inclusions called Rosenthal fibers. The fibers contain GLIAL FIBRILLARY ACIDIC PROTEIN in association with ALPHA-CRYSTALLIN B CHAIN. Rosenthal fibers are found predominantly in ASTROCYTES located in the subependymal, subpial, and periventricular areas of the BRAIN.
Canadian Medical Guide Definition Canavan Disease - A rare neurodegenerative condition of infancy or childhood characterized by white matter vacuolization and demeylination that gives rise to a spongy appearance. Aspartoacylase deficiency leads to an accumulation of N-acetylaspartate in astrocytes. Inheritance may be autosomal recessive or the illness may occur sporadically. This illness occurs more frequently in individuals of Ashkenazic Jewish descent. The neonatal form features the onset of hypotonia and lethargy at birth, rapidly progressing to coma and death. The infantile form features developmental delay, DYSKINESIAS, hypotonia, spasticity, blindness, and megalencephaly. The juvenile form is characterized by ATAXIA; OPTIC ATROPHY; and DEMENTIA. (From Adams et al., Principles of Neurology, 6th ed, p944; Am J Med Genet 1988 Feb;29(2):463-71)
Canadian Medical Guide Definition Pelizaeus-Merzbacher Disease - A rare, slowly progressive disorder of myelin formation. Subtypes are referred to as classic, congenital, transitional, and adult forms of this disease. The classic form is X-chromosome linked, has its onset in infancy and is associated with a mutation of the proteolipid protein gene. Clinical manifestations include TREMOR, spasmus nutans, roving eye movements, ATAXIA, spasticity, and NYSTAGMUS. Death occurs by the third decade of life. The congenital form has similar characteristics but presents early in infancy and features rapid disease progression. Transitional and adult subtypes have a later onset and less severe symptomatology. Pathologic features include patchy areas of demyelination with preservation of perivascular islands (trigoid appearance). (From Menkes, Textbook of Child Neurology, 5th ed, p190)

Hereditary Central Nervous System Demyelinating Diseases Medical Definitions and Terms

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