6533b7d1fe1ef96bd125cbc1

RESEARCH PRODUCT

Intraoperatives Monitoring motorischer Hirnnerven bei Operationen an Hals und Schädelbasis

subject

description

Intraoperative monitoring of cranial nerves is performed to minimize postoperative cranial nerve dysfunction. We performed electrophysiological monitoring of motor cranial nerves with a NIM 2 unit from Xomed Treace and a patient multiplexer developed in our clinic. This multiplexer allows simultaneous monitoring of 4 cranial nerves and is additionally equipped with a bipolar stimulation mode. This intraoperative monitoring was employed during 102 skull base operations. Of these 102 operations, 44 were acoustic neuroma removals by translabyrinthine approach and 36 by a middle fossa approach. Various operations including removal of tumours of the jugular foramen and the infratemporal fossa were performed in the remaining 22 patients. The facial nerve, being the most frequently monitored nerve, was evaluated both pre- and intraoperatively. Electrophysiologic data were evaluated with respect to their predictive value for postoperative facial nerve function. The relative per cent decrease in amplitude of the EMG after resection compared to that observed before resection seems to be of some predictive value for postoperative facial nerve function. A 50-60% decrease or more is associated with an increase in the House classification. Intraoperative monitoring is a useful tool in skull base surgery allowing for safer and faster identification of motor nerves in pathologic anatomic conditions. It allows the surgeon a degree of comfort by providing immediate information regarding the status of the nerve. It may also improve post-operative nerve function and shorten operating time. Additionally, neuromonitoring provides some information about expected postoperative facial nerve function.