Pyridoxine Dependency: Report of a Case of Intractable Convulsions in an Infant Controlled by Pyridoxine

A case of convulsions in an infant requiring pyridoxine for their control has been described. On oral dosage of pyridoxine 2 mg./day, seizures have now been controlled for 21 months, with no increase in dosage being required. A continuing need for pyridoxine is demonstrated by the recent reappearance of seizures following a short lapse of pyridoxine administration. In the absence of biochemical evidence of pyridoxine deficiency, as measured by xanthurenic acid excretion following a tryptophane load, and with meager clinical evidence for the complete picture of such deficiency, the authors prefer to designate this phenomenon "pyridoxine dependency" The hypothesis has been propounded that this infant suffers a metabolic anomaly in pyridoxine metabolism resulting in convulsions in the absence of regular dietary pyridoxine supplements.