Serum sodium does not correlate with seizure length or seizure threshold in electroconvulsive therapy.

Disorders of sodium balance can result in seizures. In electroconvulsive therapy (ECT) practice, it is customary to obtain electrolytes, including sodium, before treatment. A question that arises is whether the patient with mild disturbances of sodium can safely be treated with ECT or whether normalization of serum sodium is needed first. In this series, 207 patients were treated with ECT and had a serum sodium performed within a week before the first treatment. A few patients were mildly hypernatremic or hyponatremic. We found no correlation between baseline sodium and seizure threshold or seizure duration at the first treatment session. We conclude that although it is ideal to have normal sodium values before ECT, mild abnormalities do not necessarily presage prolonged seizures or lower seizure thresholds in ECT.