The purpose of this study was to evaluate a cohort of elderly patients referred by neurologists for surgical decompression of the facial nerve following botulinum toxin treatment.

In a prospective cohort study, we compared clinical outcomes and complications after surgical decompression in elderly patients that had received ≤8 and >8 botulinum toxin treatments for HFS prior to surgery.  The primary outcome was spasm-freedom. We performed logistic regression analyses to examine the relationship between age, sex, side, pre-operative symptom duration, number of pre-operative botulinum toxin treatments, and spasm-freedom at last follow-up.

Of 76 elderly patients with HFS treated with botulinum toxin, 84.2% were spasm-free at last follow-up (median 44.5 months) and 15.8% continued to have some spasms. Age (p=0.38, CI [0.38, 1.07], OR = 0.94), sex (p=0.59, CI [0.17, 2.89], OR = 0.68), side (p=0.15, CI [0.06, 1.54], OR = 0.31), pre-operative symptom duration (p=0.7, CI [0.5, 1.6], OR = 0.89), and number of pre-operative botulinum toxin treatments (p=0.3, CI [0.149, 1.81], OR = 0.52) were not predictors of spasm-freedom after surgical decompression.

Botulinum toxin is a highly safe and effective treatment for HFS. Despite this, a proportion of patients do not tolerate chronic treatment and the side effects of botulinum toxin treatment. This study provides evidence that elderly patients can undergo botulinum toxin treatment for HFS as long as desired without compromising their likelihood of achieving spasm-freedom if surgical decompression is performed in the future. Therefore, surgical decompression of the facial nerve serves as an effective rescue therapy for elderly patients with HFS refractory to botulinum toxin.