The clinicopathological spectrum of Rosenthal fibre encephalopathy and Alexander's disease: a case report and review of the literature.

Alexander's disease is a leucodystrophy that usually presents in early childhood, but can infrequently arise in adults. It is characterised pathologically by megalencephaly, demyelination, and the presence of numerous Rosenthal fibres. Most cases have been shown to be due to mutations in the gene encoding glial fibrillary acidic protein. In rare instances, numerous Rosenthal fibres have been found at autopsy in patients who have suffered protracted debilitating systemic illnesses, some with associated brain stem signs, and in very rare instances in patients with no apparent neurological abnormality. The term "Rosenthal fibre encephalopathy" is used to distinguish these cases from those of Alexander's disease. We report the first case of Rosenthal fibre encephalopathy in a young man with AIDS, and review the literature.