Athetosis and Dystonia

Abstract

Athetosis is characterized by irregular, slow, writhing, bizarre movements seen in hands and feet. Athetosis is classified as minor athetosis and major athetosis based on its magnitude. Minor athetosis is seen in patients with mild cerebral palsy. Major athetosis is caused by organic lesions of the striatum, including cerebral palsy, as a residual state of encephalitis, and after anoxic encephalopathy. In these conditions, athetosis is commonly seen in combination with dystonia. Dystonia is characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive movements or postures or both. In many cases of dystonia, the affected part of the body shows an abnormal writhing posture in the resting condition, and slow, writhing involuntary movements are superimposed on the abnormal posture with voluntary movement. For childhood-onset patients, dystonia is most commonly generalized; in adults, typically there is focal dystonia. Focal dystonia includes blepharospasm, cervical dystonia, writer’s cramp, and musician’s cramp. It is often task-specific and can be treated with local botulinum toxin injection. Generalized dystonia is caused by long use of neuroleptic drugs (tardive dystonia) and a variety of neurodegenerative diseases.