Intraoperative Electrical Stimulation for Treatment of Bell's Palsy: A Promising Strategy

Introduction: Bell’s palsy is defined as an acute onset facial nerve paralysis without an identifiable cause. While many patients fully recover from this condition with medical and physical therapy alone, there remains a subset with persistent paralysis which may result in incomplete recovery, synkinesis, and subsequent psychosocial concerns. There are currently no guidelines on surgical intervention in this population, although this subset of patients may benefit from surgical intervention. Intraoperative electrical stimulation of the facial nerve as an alternative to traditional middle cranial fossa facial nerve decompression is, at this time, a novel surgical technique. This study intends to present a unique series and add to the existing literature on surgical intervention in this population.

Methods: This was a retrospective comparison of two patient groups at our center that underwent surgical treatment for Bell’s palsy from January 1992 to March 2022. Surgery was offered for patients with persistent and complete facial paralysis, defined as House-Brackmann (HB) VI lasting for more than 3 months. The first group underwent facial nerve decompression via a middle cranial fossa approach, the second group underwent intraoperative electrical stimulation. This technique involves identification of the facial nerve in the perigeniculate region with subsequent electrical stimulation at increasing 0.1-mA increments until a stapedial response is observed. The stimulation probe is then held for 30 seconds. Statistical analysis was performed to analyze postoperative facial nerve outcomes between the two groups.

Results: There were 66 patients who met inclusion criteria, 42 (62.7%) males, mean age of 48 years. Seventeen patients underwent facial nerve decompression alone, 49 patients underwent intraoperative stimulation. Baseline characteristics, including age, BMI, and risk factors, were not significantly different between groups. Mean time from onset to first formal evaluation was 170 days. At 1 month postoperative, the mean HB score was significantly lower in the intraoperative stimulation group (3.7 vs. 4.3, p < 0.05). At 3 and 6 months postoperative, mean HB scores were not significantly different (2.8 vs. 2.3; p > 0.05) and (2.4 vs. 2.5, p > 0.05), respectively. Patients in the intraoperative stimulation group were more likely to have utilized physical therapy services (p < 0.01), there were no differences in utilization of chemodenervation treatment postoperatively (p > 0.05).

Discussion: Intraoperative electrical stimulation of the facial nerve is associated with lower HB score at 1 month postoperative, suggesting improved early functional recovery, and equivalent HB scores at three and six months postoperatively. This technique is less technically challenging, does not require ICU stay, and garners lower risk of complication. This study was limited by small uneven sample sizes and availability of remote patient data.

Conclusion: Intraoperative electrical stimulation of the facial nerve is associated with lower HB score at 1 month postoperative, suggesting improved early functional recovery, is easier with less risk to the patient, and should be considered in patients with symptoms refractory to medical management unlikely to regain function. Opportunity for future work includes larger sample size with multi-surgeon collaboration.

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Artikel online veröffentlicht:
05. Februar 2024