Evoked potentials were used to measure neural function in relation to blood glucose concentration in 17 children at the Department of Child Health, University of Newcastle upon Tyne. Thirteen children were admitted for investigation of metabolic or endocrine disorders and hypoglycemia was provoked by fasting or insulin administration; 4 had recurrent episodes of spontaneous hypoglycemia. Abnormal brainstem auditory evoked potentials were recorded in 9 and abnormal somatosensory evoked potentials in 1 of the 11 children whose blood glucose concentration remained above 2.6 mmol/1; 5 of these 10 children were asymptomatic and 5 became drowsy. No change in evoked potentials was recorded in the 6 children whose blood glucose concentration remained above 2.6 mmol/1. Of the 10 children with abnormal evoked potentials, 6 had normal latencies immediately after the IV administration of 25% dextrose (2ml/kg) or the IM administration of glucagon (20 ug/kg), whereas 4 had persistently prolonged I-V latencies or absent wave V for 1 hr, 1.5 hrs, 16 hrs, and 2 days. The authors suggest that blood glucose concentration should be maintained above 2.6 mmol/1 to ensure normal neural function in newborns and children irrespective of the presence or absence of abnormal clinical signs. [1]