Surgical Treatments for Facial Aberrant Reinnervation Syndrome: A Systematic Review

Background: Facial aberrant reinnervation syndrome is characterized by aberrant facial muscle reinnervation after facial nerve injury producing facial synkinesis, hypertonicity, and muscle spasm. Objective: To systematically review the surgical treatments for facial aberrant reinnervation syndrome and assess their effectiveness as measured by patient-reported outcomes, physician-graded outcomes, or computer-automated grading systems. Methods: We conducted a systematic review using PubMed, Embase, and Cochrane CENTRAL in accordance with PRISMA guidelines. Texts reporting outcomes of any surgical treatment for facial aberrant reinnervation syndrome from 2003 to 2023 were included. Results: After screening, 25 studies with 731 patients were included. Surgical procedures included selective neurectomy (SN), selective myectomy (SM), cross-facial nerve graft, masseter nerve transfer, and gracilis muscle transfer. All surgical techniques and combinations showed significant improvement in at least one clinical outcome measure from baseline (p < 0.05), although one study found no significant improvement. Thirty different outcome measures were used, the most common being the FaCE and eFACE scales (seven studies each). Conclusions: All surgical procedures in this review yield improved clinical outcome measures for facial aberrant reinnervation syndrome, with SN and SM being the dominant surgical treatments. Standardized outcome assessment and more nuanced patient evaluation are necessary to determine the most effective surgical treatments.