Transient asystole during surgery for posterior fossa meningioma caused by activation of the trigeminocardiac reflex: three case reports.

Three patients undergoing surgery for cerebello-pontine angle meningioma suffered transient episodes of asystole. All patients exhibited return to the previous heart rate with cessation of surgical manipulations and administration of anticholinergic agents. These reactions were apparently elicited by activation of the trigeminocardiac reflex (TCR) by direct stimulation of the trigeminal nerve or branches in the dura mater or cerebellar tentorium. Remifentanil was used in all three cases as an anesthetic agent, so may be a cause of the TCR. The possibility of activation of the TCR should be considered during surgical manipulation around the trigeminal nerve or the distribution of the trigeminal nerve branches. Transient bradycardia, hypotension, or asystole can occur regardless of whether there is pressure on the brainstem during posterior fossa meningioma surgery.