Prevention of intractable partial seizures by intermittent vagal stimulation in humans: preliminary results.

Intermittent stimulation of the vagus nerve in four patients resulted in complete seizure control in two, a 40% reduction of seizure frequency in one, and no change in seizure frequency in the other. Side effects (hoarseness, stimulation sensation in the neck, and hiccups) were transient and occurred concomitantly with stimulation. All patients tolerated increasing stimulation parameters well. The results, however, are inconclusive because of the brief duration (6-12 months) of follow-up. Vagal stimulation represents a novel approach for seizure control in patients who have intractable epilepsy, but additional studies are needed to clarify the efficacy and safety of the procedure and to define selection criteria for patients.