A Study on Clinical Profile of Hemifacial Spasm in India and the Therapeutic Response to Botulinum Toxin Type A Injection as well as Pre and Postinjection Quality of Life.

[BACKGROUND] Hemifacial spasm (HFS) is a distressing, involuntary, irregular tonic-clonic contraction of the facial muscles innervated by the seventh cranial nerve. It affects the quality of life. Botulinum toxin is a preferred symptomatic treatment option for the condition. However, there is a lack of study in the Indian scenario. Therefore, we observed the demographic profile, clinical spectrum, therapeutic response, and adverse effects of botulinum toxin and assessed the quality of life in the pre and postinjection phases in our subjects with HFS.

[MATERIALS AND METHODS] The study design is a prospective open-label observational study. Consecutive cases of HFS were selected from the general neurology outpatient department (OPD) and movement disorder clinic of a medical college hospital in Eastern India. Clinical and relevant neuroimaging studies excluded mimickers and secondary causes of HFS. Institutional Ethics Committee's permission was obtained. Informed consent was taken from patients before botulinum toxin injection. The pre and postinjection assessment tools were spasm rate for a specific period of time, quantification of facial asymmetry, widening palpebral fissure by visual analog scale, Jankovic disability rating scale, HFS-7 scale, and videography.

[RESULTS] A total of 250 cases of HFS (F:M = 138:112) were studied. The mean age of presentation was 47 years. The mean dose of botulinum toxin injection was 24.2 units per patient. The mean duration of improvement was 4 months. The spasm frequency was decreased by 90%, and the facial asymmetry was improved by 86%. The improvement in quality of life was 86%. Local adverse effects are seen in 10.4% of cases, and all were reversible.

[CONCLUSION] This is one of the largest studies on the effects of botulinum toxin in subjects with HFS in the Indian population. Periodic injection of botulinum toxin is a safe and effective therapy for subjects with HFS. There is a significant improvement in the quality of life following botulinum toxin therapy in subjects with HFS. Adverse effects were local, mild, well-tolerated, and reversible.