Hemi-Facial Spasm
What is Hemifacial Spasm?
Hemifacial Spasm is a highly localised form of segmental dystonia in which unpredictable and involuntary spasms, or twitching, contort the various muscles on one side of the face. Although the spasms are intermittent, in the worst cases patients can suffer from facial disfigurement and functional impairment. Everyday activities such as driving and reading may be difficult and ordinary social inter-action may be restricted. Hemifacial Spasm affects both sexes equally and onset is usually in middle age. The true incidence is difficult to estimate because of the problems of accurate diagnosis, but at least 5,000 patients in the UK alone are thought to be affected.
How is Hemifacial Spasm treated?
The use of drugs such as carbamazepine and clonazepam has been shown to have only a limited effect. Therefore, surgical treatment of Hemifacial Spasm has often been the preferred option. More recently, injections of botulinum toxin (type A) has proved to be an effective treatment, relieving spasm by relaxing the affected muscles. Treatment with botulinum toxin (type A) takes effect three to seven days after injection. The effect of each treatment lasts up to four months.