Detailed Analysis of Neurological Status and Functional Outcome after Spinal Accessory Nerve-Facial Nerve Anastomosis: Comparison versus Other Reinnervation Procedures in Reported Series

Introduction: Few long-term studies of spinal accessory nerve–facial nerve anastomosis (AFA) for facial nerve (FN) palsy exist.

Objective: The purpose of this study was to evaluate facial reanimation efficacy after spinal accessory nerve–facial nerve anastomosis (AFA) using scales for neurological and functional outcome analysis. The authors reported their long-term results of AFA and compared them with other substitute procedures according to literature review.

Methods: Between 1998 and 2010, 20 patients underwent AFA with the major trunk of the spinal accessory nerve. The mean duration of follow-up was 4.65 years (range, 1–10 yrs). All patients in the series had total facial nerve (FN) function loss after acoustic neuroma surgery. Six patients had conjoined trigeminal nerve dysfunction. The interval between FN loss and the operation was from 1 to 6 months (mean, 4.7). Twelve patients received facial muscles retraining and shoulder exercises as well as a facial electrical stimulation for a year after the surgery. Video-recording of participants were made, so FN and shoulder function were measured in each patient by physicians who did not participate in the surgery. Each patient was carefully evaluated utilizing the House-Brackmann (HB) facial grading systems and the Yanagihara system (YS) for the severity of paresis; the Sunnybrook Facial Grading Scale (SFG) for facial symmetry and synkinesis. Facial Disability Index (FDI) was used for patients' self-assessment. The original questionnaire, Shoulder Disability Index (SDI), which includes four questions about shoulder function, was generated and used for denervated segment self-assessment (full marks: 100 points).

Results: Overall, 4 patients (20%) recovered from facial palsy with final HB grade II, 11 (55%) patients with HB III and 5 patients (25%) had HB IV-V. Mean YS score was 27.5 (± 4.06), mean postoperative SFG score was 71.1 (± 9.38). Self-assessment tools revealed mean total postoperative FDI of 143.75 (± 22.82) points and mean SDI of 69.06 (± 22.16). Statistical comparison was made for all received data. There was a significant correlation (P < 0.001) between the HB, YS, and SFG postoperative scores as well as between total FDI versus SDI (P < 0.001). Patients who underwent postoperative exercises and electrotherapy showed better outcomes (P < 0.05).

Conclusion: AFA results are comparable with other reinnervation procedures. This procedure is feasible and beneficial for patients with total loss of FN function after skull base surgery and improves quality of life. The best functional result provides AFA combined with subsequent physiotherapy. Subjectivity is the main issue in the facial expression evaluation, so assessment and self-assessment scales are needed for the global evaluation of FN functions. Denervated segment function after the substitute procedures must be measured using specific scales.