Long term outcome study on botulinum toxin A treatment for primary hemifacial spasm

Hemifacial spasm is usually treated with botulinum toxin A (BTX-A) injections, a proven symptomatic therapy. However, little has been reported on the long-term outcome of patients treated with BTX-A. We reviewed patients with hemifacial spasm treated with BTX-A at the University of Malaya Medical Centre between 1995 and 2003. Of the 82 patients in our BTX-A database, we were able to contact 68 patients to participate in the study, 79% women. They were assessed after a mean duration of disease of 9.5 years and mean duration of 4 years after the first BTX-A injection. Patients were asked the response to BTX-A therapy, to grade their functional severity at baseline prior to BTX-A treatment and at follow up in this study, and asked if they thought their hemifacial spasm had improved since the commencement of treatment. The majority (87%) still reported improvement after their most recent BTX-A injections. At baseline, 50% were mild, not interfering with daily living; 38% were moderate, some interference with daily living and 12% severe, significantly interfered with daily living. At follow up, 35% were mild, 54% moderate and 4% severe. Four (6%) had complete resolution of their spasm. Overall, 19% reported worsening, 57% reported no change, and 24% felt that their condition had improved. Six patients developed permanent facial weakness. In conclusion, hemifacial spasm is a chronic disorder, with 6% reporting complete remission after 9.5 years of onset of illness. BTX-A injection continues to be effective after 4 years of repeated injections.