Neurovascular decompression in trigeminal neuralgia: role of intraoperative neurophysiological monitoring in the learning period.

This paper deals with the first 45 consecutive patients undergoing microvascular decompression (MVD) surgery for trigeminal neuralgia, studied with perioperative brainstem auditory evoked potentials (BAEPs) and electromyography (EMG). We observed a good correlation between the intraoperative BAEP modifications and postoperative hearing function. BAEP monitoring was useful in identifying the manoeuvres that may compromise cochlear nerve function. This improved the surgical technique in the subsequent cases and reduced the incidence of iatrogenic hearing deficits after the learning period. There were no correlations between the entity of the intraoperative EMG discharges and the postoperative facial and trigeminal function. Intraoperative EMG monitoring can be useful during the period of learning as a means of identifying the different nerves in the cisternal tract.