Nocturnal convulsions and insulin-induced hypoglycaemia in diabetic patients.

Convulsions may occur as a consequence of insulin-induced hypoglycaemia. We report three patients with insulin-dependent diabetes, who presented with generalized tonic-clonic seizures associated with nocturnal hypoglycaemia. None of the patients had experienced hypoglycaemia during waking hours and the convulsions were mistakenly diagnosed as idiopathic epilepsy. Recognition of the possible hypoglycaemia aetiology of these convulsions permitted appropriate alteration of the insulin regimens with no recurrence of convulsions. In one case, the seizure was associated with bilateral fractures of the neck of the humerus. Unrecognized hypoglycaemia should be considered as a possible cause of convulsions in insulin-dependent diabetic patients.