[Coexistence of two hemodynamically significant mechanisms for syncope associated with glossopharyngeal neuralgia].

Syncope is a rare presentation of glossopharyngeal neuralgia (GN). A patient with squamous cell cancer of the pharynx had GN and syncope due to asystolic pauses and extreme hypotension. The bradyarrhythmias were atropine-sensible, but both this treatment and pacing failed to prevent recurrence of syncopal hypotensive crises, blood pressure continuing to fall during GN attacks. These data suggest that during a neuralgic attack the stimulation excites vagi, causing asystole, and simultaneously abolishes sympathetic tone. Carbamazepine was effective in controlling the symptoms of the patient.