Patterns and timing of recovery from facial nerve palsy after nerve-sparing parotid surgery: the role of neuromuscular retraining

Objectives: Among the complications of parotid surgery, facial palsy is frequent and burdened by high functional and social impact for the patient. There are few data on the efficacy of facial neuromuscular retraining (FNR) in patients with facial palsy after parotid surgery, and no data exist on its impact in timing and extent of recovery. Material and methods: A retrospective study was conducted on patients undergoing FN sparing parotid surgery and suffering from postoperative facial palsy. Among 400 patients undergoing surgery between July 2016 and May 2023, those with the preservation of the FN and onset of facial palsy were selected. Nerve function was evaluated during 2 years follow up using the House-Brackman (H&Bs) and Sunnybrook scales (SBs). Results: A total of 46 patients undergoing partial or total parotidectomy were included. At discharge 18 patients (39,1%) had IV to VI grade paralysis according to the H&Bs and the mean SBs value was 54. At 2 and 6 months after surgery, the average value of Sunnybrook increased to 76.5 and 95.4 respectively. After 12 months no patients with IV to VI grade paralysis were represent in our cohort. Two years after surgery, only five patients (10.9%) had persistent grade II paralysis according to HBs. Conclusions: Our study supports the efficacy of FNR in the rehabilitation of facial paralysis after nerve-sparing parotidectomy. The greater functional improvement is achieved within the first 6 months of rehabilitation. A significant improvement is detected still after 18 months, supporting the importance of long rehabilitation for patients without complete recovery after the first year.