METHODS: Patients' images and medical notes were retrospectively reviewed with subsequent analysis of both the therapeutic outcomes and complications of Botox injections.

RESULTS: The information of 76 patients(Female=58)with HFS who received a minimum of 4 Botox injections were included. The mean follow-up interval was 83±50(20-112)mo with an average of 16±10(4-34)injections. The peak incidence was between 55 and 64 years and the average age of onset was 66±11(32-85)years. Up to 23% of patients with HFS had aberrant vascular structures(Right=8, Left=7)in close relationship to the facial nerve(MRI=14, CT=1), where the vertebral artery(n=6)was the most involved vessel followed by the anterior inferior cerebellum artery(n=5). Patients with primary HFS had a shorter effective duration(2.5 vs 3.1mo, P<0.05), a longer onset time(4.1 vs 3.8d, P=0.739)and a lower Subjective Spasm Alleviation score(SSAs)(1.7 vs 1.9, P=0.179)than those with secondary HFS. Twelve of the 19 patients with pre-existing eyelid diseases underwent surgical correction including upper blepharoplasty(n=12), limited myectomy(n=7), browplasty(n=7)and advancement of levator aponeurosis(n=5). Five(41.7%)of those with surgical correction and suboptimal response to Botox showed improvement 6mo after surgery \〖onset time(P=0.0256), effective duration(P=0.374)and SSAs(P=0.0161)\〗. Those 12 patients with eyelid surgery had a lower complication rate than those without eyelid surgery(23% vs 42%, P≤0.05).

CONCLUSION: Botox is an effective and safe treatment for HFS. We found that patients with primary HFS had a less favorable therapeutic outcome with Botox than those with secondary HFS. Eyelid surgery for patients with concurrent eyelid diseases can augment the effect of subsequent Botox injections by improving patient satisfaction and reducing complication rate.