Normocalcemic tetany. A problem of erethism.

A boy with neonatal and childhood convulsions had prolonged attacks of tetany in adolescence. There was no abnormality of serum calcium or magnesium, and treatment with these cations was ineffective. There was no respiratory alkalosis, and attacks occurred when the patient had not taken anticonvulsant drugs for years. Serum parathormone content and renal responses to the administration of parathormone were normal. "Normocalcemic tetany" seems an appropriate name for the condition, which was probably genetic since the patient's brother and mother had signs of latent tetany and the brother had a convulsive disorder. The cause of the syndrome is not known, but it seems to be an abnormal response of neural membranes rather than an abnormality of calcium homeostasis.