Delayed recurrence of hemifacial spasm after successful microvascular decompression: follow-up results at least 5 years after surgery

Microvascular decompression (MVD) for hemifacial spasm (HFS) is regarded as the gold-standard treatment due to its efficacy and durability. However, some patients still suffer from delayed recurrence after initially successful MVD.In this study, we describe our clinical experience in a single institute following up initially successful MVD for HFS 5 or more years after surgery. We analyzed the probability of, risk/predisposing factors for, and timing of delayed recurrence. We retrospectively reviewed data from 587 patients meeting our inclusion criteria who underwent MVD for HFS from March, 1999, to June, 2006. We evaluated the time-dependent probability of recurrence and factors affecting delayed recurrence and time of recurrence. The probability of delayed recurrence was 1.0, 1.7, and 2.9 % at 1 year, 2 years, and 5 years after surgery, respectively. Mean time to recurrence was 153.1 months (95 % confidence interval [151.4-154.9]). The probability of late recurrence was increased in patients with co-morbid arterial hypertension (p = 0.036). However, there was a trend towards an association of delayed recurrence with co-existence of young age, male gender, vein or VA offender, and experience of transient facial weakness. Delayed recurrence of HFS after initially successful MVD is rare; however, there are patients who experience delayed recurrence more than 2 years after MVD, even until 5 years after MVD. Our results suggest that arterial hypertension contributes to late recurrence. We did not find a statistically significant relationship between recurrence and other putative risk/predisposing factors.