Isolated hypomagnesaemia presenting as focal seizures in diabetes mellitus.

Hypomagnesaemia is a well known association of diabetes mellitus; it is often asymptomatic but may manifest as tremor, tetany, delirium, hallucinations, or, when severe, generalised seizures. In such instances it is usually associated with hypocalcaemia. We report on a diabetic patient with severe hypomagnesaemia but normocalcaemia who developed focal seizures that proved refractory to conventional anticonvulsant treatment but were abolished when the serum magnesium concentration was corrected.