[A case of trigeminocardiac reflex in the pterional approach].

Trigeminocardiac reflex (TCR) is a type of vasovagal reflex which happens in stimulation of the trigeminal nerve. We present a case of TCR in the pterional approach for clipping of an unruptured anterior communicating artery (Acom) aneurysm. A 69-year-old female was evaluated because of syncope. MRI showed incidentally Acom aneurysm. During the operation for clipping this aneurysm, only when we manipulated the dura attached to the sphenoid ridge, a total of three times, asystole appeared temporarily. In this case, a branch of the trigeminal nerve accompanying the middle meningeal artery was stimulated, then TCR may have been induced, leading to asystole. Furthermore, it seems that remifentanil used for anesthesia is related to TCR.