Computed tomography in Pelizaeus-Merzbacher disease.

CT findings in two related males suffering from the classical X-linked recessive form of Pelizaeus-Merzbacher disease (PMD) are described. CT revealed marked cerebellar atrophy and focal areas of demyelination of cerebral white matter in a 25-year-old patient. This agrees with known neuropathological changes. However, CT was normal in the 14-year-old nephew, although his neurological symptoms were nearly as severe as his uncle's. Judging from this observation and from the scant information in the literature it seems that CT in classical PMD is normal in the first decade and is therefore not helpful in confirming the diagnosis of PMD at an early stage.