Dystonia

Abstract

Dystonia is a movement disorder characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive, movements, postures, or both. Dystonic movements are typically patterned, twisting, and may be tremulous. Dystonia is often initiated or worsened by voluntary action and associated with overflow muscle activation. This chapter details the phenomenology of dystonic movements, and discusses the classification and treatment of dystonia. The phenomenology of dystonia combines abnormal movements and postures. The main features of dystonia include the following: voluntary action, dystonic tremor, overflow of movements, mirror dystonia, and alleviating maneuvers. Dystonia is usually worsened by fatigue and stress and is suppressed by sleep, hypnosis, or relaxation. Treatment is tailored by etiology. Management can be difficult and may require more than one modality of treatment and multiple strategies may be needed. Surgical therapies include: peripheral surgical procedures, central nervous system ablative procedures, and deep brain stimulation.