INS and pancreatic insulinoma: Although PSG was not performed, the authors suggest that the abnormal secretion of insulin and hypoglycemia that occurs in insulinoma patients during night is due to the incapacity to react normally to the prolonged fasting condition or to the sleep itself.15 In case 2, during PSG, we observed episodes of abnormal movements that were likely due to hypoglycemia, and these abnormal movements occurred after Stage N2.