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.
Methods:
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.
Conclusion:
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.
