gms | German Medical Science

Objective: In microvascular decompression procedures of the facial nerve for hemifacial spasms electrophysiologic monitoring is used routinely. Resolution of lateral spread in EMG monitoring of the facial nerve is a characteristic intraoperative finding after decompression of the nerve. A positive correlation with outcome has been described by others. We sought to retrospectively review our cases in order to assess for this correlation.

Methods: A total of 38 consecutive cases were reviewed. Clinical and intraoperative findings were assessed. Fisher two-tailed test was performed to evaluate for positive correlation of resolution of lateral spread and clinical outcome.

Results: A standard retrosigmoid approach in the lateral decubitus position was used for the decompression procedure. As expected, the anterior inferior cerebellar artery was the predominant compressive vessel (n = 10), although no intraoperative significant compression was found in seven patients. Twenty-two patients had immediate, sustained relief from the symptoms of hemifacial spasm. Of 36 patients with detected lateral spread prior to nerve decompression, a complete resolution of this EMG finding was found. However, a positive correlation could not be detected (p = .72).

Conclusions: In our series, there was no positive correlation of resolution of intraoperative lateral spread to resolution of symptoms of hemifacial spasms in microvasular decompression procedures.