It has been reported by Hoffman and Wunsch1 and Riboli2 that electrical stimulation applied to the head will arouse patients from hypoglycemic coma. Whereas Hoffman and Wunsch applied a pulsating direct current in the nonconvulsive method of Hirschfeld,* Riboli used a prolonged administration of low-voltage alternating current of 50 to 80 ma. These workers suggested that the return to consciousness was due to diencephalic stimulation by transcerebrally directed current. This transcerebral-diencephalic stimulation theory is commonly mentioned in reports on nonconvulsive electroshock therapy and reports on the treatment of barbiturate coma by nonconvulsive techniques.† With respect to barbiturate-induced coma this hypothesis has been seriously challenged by Blachly and Brookhart.5 These investigators have found that the respiratory augmentation accompanying electrical stimulation can be ascribed solely to the activation of afferent nerves and that direct stimulation of the brain is not an essential element in the production of the response.
JONES CH, BLACHLY PH, BROOKHART JM. The Analeptic Action of Peripheral Electrical Stimulation in Insulin Coma. AMA Arch NeurPsych. 1955;73(5):560-564. doi:10.1001/archneurpsyc.1955.02330110076011