Tic, tremors and other hyperkinesias

Abstract

Until recently, botulinum toxin was most commonly used for the treatment of motor disturbances characterized by excessive involuntary muscle activity such as distonia and spasticity. The efficacy of and safety of botulinum toxin in these conditions has led to the exploration of its use in a broadening range of movement disorders including hand and jaw tremor, vocal and motor tics, focal myoclonic jerks, continuous facial myokymia, bruxism, stiff person syndrome, camptocormia, freezing of gait in Parkinson's disease, and prevention of contractures related to prolonged rigidity and immobilization in akinetic rigid syndrome due to Parkinson's disease or corticobasal degeneration. This article will provide an update on the uses of botulinum toxin in the field of movement disorders other than dystonia and spasticity, drawing special attention to theoretical and practical treatment issues. Available experience with botulinum toxin suggests that it may be an effective and safe treatment not only for approved indications but also for an increasing number of off-label indications. However, controlled studies for many such conditions are lacking, and more controlled clinical trials are warranted.