Effects of Pyridoxine Withdrawal on Cerebral Circulation and Metabolism in a Pyridoxine-dependent Child

Abstract

RECENT studies have established a relationship between vitamin B₆ metabolism and convulsive disorders of the nervous system. Pyridoxine deficiency in young animals and human infants and the administration of pyridoxine antagonists in animals have been observed to cause convulsive activity which is rapidly alleviated by administration of pyridoxine^1,2. Several instances have been reported of children with abnormally high vitamin B₆ requirements^1,3. On ordinary dietary vitamin B₆ intake, they appear, at least as regards their nervous system, to be suffering from a relative vitamin B₆ deficiency and are subject to convulsions which are rapidly terminated by pyridoxine administration, or entirely prevented by pyridoxine supplementation of the diet. In order to investigate further the nature of the cerebral metabolic disturbances occurring in vivo in vitamin B₆ deficiency, measurements of cerebral blood flow, oxygen consumption, and respiratory quotient were made in one of these pyridoxine-dependent children during a period of seizure activity induced by withdrawal of pyridoxine from the diet and immediately after its alleviation by parenteral administration of pyridoxine.