Hirschfelder1 first described clinical symptoms in man resulting from a deficiency of magnesium in 1934. Twenty years later Flink2 confirmed that neuromuscular hyperirritability may result from magnesium want and reported that such patients may also develop hallucinations. These findings have subsequently been confirmed by other investigators.3 During the past five years we have observed 18 patients with the magnesium deficiency syndrome other than alcoholic delirium tremens, some of whom showed clinical findings not heretofore described. In addition, some of the predisposing medical conditions leading to the magnesium deficiency in this group of patients have not previously been stressed.
The clinical picture of magnesium deficiency is principally characterized by neuromuscular and central nervous system hyperirritability, although cardiovascular disturbances may be observed. A tremor is seen in most of the patients (table 1) which consists of athetoid or choreiform movements. The tremor may be accentuated by asking the patient