Pelizaeus-Merzbacher disease: clinical and nosological study.

Pelizaeus-Merzbacher disease can be diagnosed on genetic and clinical criteria. These include: involvement of several males in a lineage in a manner consistent with X-linked recessive inheritance; early nystagmoid movements; precocious psychomotor deterioration; progressive pyramidal, dystonic, and cerebellar signs. We present seven cases from three families and review 148 cases in 19 families from the literature. Laryngeal stridor present in two of our patients may be a presenting feature. Neurophysiological investigations may be helpful in the diagnosis.