Answer and Discussion of Quiz Set: N-009

2.    In addition to Canavan's disease, which of the following diseases are also characterized by progressive enlargement of the head?

A.  Mitochondrial myopathy, encephalopathy, lactic-acidosis, and stroke like episodes (MELAS)

B.  Cerebral amyloid angiopathy (CAA)

C.  Moyamoya disease

D.  Alexander's disease

E.  Ophthalmoplegic retinitis pigmentosa with polyneuropathy

Answer and Discussion: The answer is (D). Alexander's disease is a slowly progressive and fatal leukodystrophy due to mutation of the glial fibrillary acidic protein (GFAP) gene. Clinically, it is featured by clinically a progressive, sometimes very slow, process with dementia, seizures and spasticity.clinically a progressive, sometimes very slow, process with develomental delay, dementia, seizures, spasticity, and progressive enlargement of the head (macrocephaly). Pathologically, it is a degenerative disorder of the central nervous system characterized by diffuse demyelination and rarefaction of the white matter, with little or no sparing of the arcuate fibers, and widespread accumulation of Rosenthal fibers.