Delayed complete remission of hemifacial spasms following microvascular decompression and the implications for optimal time of revision surgery.

Abstract

Microvascular decompression (MVD) is an effective method for directly treating hemifacial spasms (HFS). The timing for the consideration of failed MVD and reoperation has been paradoxical. This study aimed to investigate the delayed complete remission of HFS in terms of prevalence rate, duration between surgery and delayed complete remission, and predictive factors. A hundred patients with HFS who underwent MVD from 2012-2021 were enrolled in the study. All HFS occurred as a result of compression of the facial nerve by adjacent blood vessels. Clinical information, intraoperative findings, and surgical outcomes were incorporated for data analysis. In the first week after MVD, 67 of 100 patients achieved complete remission of HFS, while the remaining 33 had incomplete remission. In long-term follow-up, 26 individuals gradually developed delayed complete remission with a median duration of 9.1months. Finally, 86 of 100 patients achieved complete long-term remission. Recurrent HFS and incomplete remission were found in 7 and 7 patients, respectively. Factors associated with postoperative complete remission in the first week were a severe degree of facial nerve compression (p = 0.047, OR 2.75, 95% CI 1.01-7.40), with long-term complete remission was left-sided HFS (p = 0.012, OR 5.73, 95% CI 1.47-22.36), and with the appearance of delayed complete remission was the prolonged duration of HFS at least 3years before MVD (p = 0.046, OR 3.75, 95% CI 1.03-13.76). Transient facial paresis was found in 11% of the patients. Of them, facial nerve function recovered completely in all cases. A delayed complete remission of HFS could be expected in long-term follow-up after MVD and is probably related to a longer duration of HFS before surgery. Unnecessary reoperation should be avoided in the early years following the first surgery.