Recurrent facial palsy: The prognostic value of electrophysiological tests according to recurrence interval.

OBJECTIVE

The prognostic value of nerve excitability tests (NET) and electroneurography (ENoG) for recurrent peripheral facial palsy is poorly understood. This study aimed to evaluate the association between NET/ENoG results for the current palsy and recovery.

METHODS

We extracted data on patients who were referred to our hospital (2005-2017). Adult patients with recurrent peripheral facial palsy who underwent NET and ENoG within 3 weeks of onset were retrospectively analyzed (n = 26). Favorable recovery was defined as the achievement of either House-Brackmann grade I/II or the same level of facial movement as before the current palsy. We evaluated the predictive NET/ENoG results by making comparison between the favorable recovery group and the unfavorable recovery group, which were subdivided based on the length of time after the previous palsy.

RESULTS

In terms of patients with a >4-year recurrent interval, 8 out of 12 patients achieved favorable recovery. Compared to the favorable recovery group, the unfavorable recovery group had significantly higher NET results (9.03 mA vs. -1.08 mA, p = 0.017). Also, the unfavorable recovery group had significantly higher NET results in patients with a >2-year recurrent interval (9.03 mA vs. 1.06 mA, p = 0.036). However, other test results (NET in ≤4-year recurrent interval/all 26 patients, and ENoG in >4-year recurrent interval/≤4-year recurrent interval/all 26 patients) did not differ significantly between patients with favorable and unfavorable recovery.

CONCLUSION

NET might be a useful prediction method in patients with at least a few years interval between the previous and the current palsy.