The Clinical Use of Botulinum Toxin in the Treatment of Movement Disorders

Spasmodic torticollis (cervical dystonia), blepharospasm, and writer’s cramp are specific types of a group of movement disorders known as dystonias. Dystonia is a neurological condition of unknown cause. Some types of dystonia have a genetic component. Involuntary contraction and spasms of one or more of a group of muscles anywhere in the body characterize these disorders. This frequently involves muscles of the face, neck, arms or legs. This can cause abnormal posturing of the head, neck, and extremities. Many different types of treatment have been used in an attempt to control the disabling symptoms of these diseases. These have included various types of medications as well as surgical procedures. None have proved to provide any degree of lasting benefit. In the early 1990’s, the Food and Drug Administration approved the use of botulinum toxin Type A (Botox) injections for the treatment of certain types of dystonia. The FDA approved botulinum toxin Type B (Myobloc) for clinical use in early 2001. Although not a dystonia, hemifacial spasm is characterized by episodic twitching or spasms of the facial muscles on one side of the face. Botulinum toxin has proved to be highly effective in the treatment of hemifacial spasm as well as spasmodic torticollis, blepharospasm, and writer’s cramp. Newer uses of Botox include treatment of spasticity, focal soft tissue pain disorders (myofascial pain), migraine and related headache disorders and temporal-mandibular joint related disorders such as bruxism. Botox injections have been used successfully to cosmetically smooth out facial wrinkles.