Autonomic failure in hydrencephaly.

Autonomic functions were studied in three patients with hydrencephalus and five with hydrocephalus. Autonomic failure of central origin was found in the patients with hydrencephalus; whereas, those suffering from hydrocephalus had essentially normal autonomic function. In two patients with hydrencephalus, the hypothalamus was markedly abnormal but the rest of the autonomic nervous system was histologically normal. From this it is concluded that in some patients with mental and motor retardation, autonomic failure may be of cerebral origin but that this is not a feature of patients with hydrocephalus.