Episodic hyperhidrosis, hypothermia, and agenesis of corpus callosum.

Episodic hyperhidrosis and hypothermia are the primary symptoms of a rare central nervous system disorder of thermoregulation which is often associated with agenesis of the corpus callosum and can present in childhood or adult years. During attacks, patients may exhibit confused, withdrawn, and lethargic behavior and ataxia or other neurologic symptoms. A 21-year-old man with temperature chronically between 30 and 32 degrees C transiently responded to phenobarbital and to cyproheptadine therapy. A 34-year-old woman with frequent, brief episodes of hypothermia and hyperhidrosis improved with chlorpromazine treatment. Episodic thermoregulatory disturbance has been attributed to "vagal attacks" or "diencephalic epilepsy," but the pathophysiology remains undefined.