[The identification and functional tracking of the facial nerve during the removal of tumors of the cerebellopontine angle].

Intracranial identification by electrostimulation and monitoring of the status of the facial nerve was intraoperatively used in 21 patients with cerebellopontine angle tumors of varying histological structure. Monopolar and bipolar electrostimulation, as well as electromyography and mechanography for recording the function of the facial nerve were compared. During removal of cerebellopontine angle tumors, identification and monitoring of the function of the facial nerve provide anatomic retention of this nerve when the tumor is radically eliminated. This is of essential significance for acoustic neurinomas. A combination of monopolar and bipolar stimulation for identification of the facial nerve simplifies removal of these tumors. As compared with electromyography, mechanography of facial nerve function during these operations is a more convenient technique due to the simplicity and absence of false operation for electric interferences. The study provided the optimum procedure for intracranial stimulation to identify the facial nerve within the cerebellopontine angle.