Microsurgical techniques and intraoperative cranial nerve monitoring have considerably improved the results of vestibular schwannoma (VS) surgery. More in detail, the preservation of facial nerve (FN) function is generally accomplished in the great majority of the cases, at least for small and mediumsized tumours. Intraoperative FN monitoring is usually performed with electromyographic (EMG) devices, placing subdermal needle electrodes in the facial muscles and recording spontaneous or elicited EMG responses. After the tumour has been removed, the FN is electrically stimulated at its exit from the brain stem. Many studies have been performed, comparing the results of these electrophysiologic techniques, in terms of stimulation thresholds and response amplitudes, in order to predict early and long-term postoperative facial nerve function after VS resection. The common experience of surgeons is also that a mechanical stimulation of the nerve can evoke the typical "burst" responses, suggestive of FN integrity. In our experience when EMG activity is elicited during surgical procedures and after tumor removal stimulating mechanically the FN with a dissector, it is generally evocative of a good functional outcome. In order to confirm this observation, we performed a retrospective study of 250 patients affected by VS, consecutively operated on between 1989 and 2001 at our interdisciplinary centre. Preoperative charts, intraoperative data, and postoperative results were reviewed and statistically analysed in relation to the presence of EMG activity evoked by mechanical stimulation of the FN.
|Number of pages||1|
|Issue number||SUPPL. 2|
|Publication status||Published - 2001|
ASJC Scopus subject areas
- Clinical Neurology