gms | German Medical Science

Objective: The treatment of hemifacial spasm using microvascular decompression (MVD) is still challenging regarding postoperative outcome. A limitation of this treatment is insufficient improvement in a certain proportion of patients. Therefore, botulinum toxin has emerged as an alternative treatment option. In order to improve the outcome of the surgical procedure the effect of intraoperative EMG monitoring of lateral spread during MVD for the treatment of hemifacial spasm has been analyzed. The achieved results are summarized in a current study.

Method: In the period 1991-2012 a consecutive series of a total of 69 patients underwent surgery of hemifacial spasm using MVD. The outcome of routine EMG and BAEP monitoring (group_1: n = 19 patients, period 1991-2001) was retrospectively investigated in comparison to the additional EMG monitoring of the lateral spread (group_2: n = 49 patients, period 2002-2012) with one patient lost to follow-up. For both patient groups the immediate postoperative and the long-term outcome were analyzed.

Results: Concerning group_1 measured with routine EMG and BAEP monitoring only a total of 12 out of 19 patients (rate = 63%) had an immediate postoperative relief of spasm. On the long-term 14 out of 19 patients (rate = 74%) had entire relief of spasm. In contrast to that regarding group_2 which was additionally measured with intraoperative monitoring of lateral spread, a total of 43 out of 49 patients (rate = 88%) had an immediate postoperative relief of spasm. On the long-term 48 out of 49 patients (rate = 98%) had entire relief of spasm.

Conclusions: The presented results clearly demonstrate the striking positive effect of EMG monitoring of the lateral spread during MVD on the immediate and long-term outcome in the surgical therapy of hemifacial spasm. In consequence, microvascular decompression is a safe and the only curative treatment option in contrast to botulinum toxin.