Official websites use. Share sensitive information only on official, secure websites. Address for correspondence: Joel S. Perlmutter, M. Louis, MO Task-specific dystonias are primary focal dystonias characterized by excessive muscle contractions producing abnormal postures during selective motor activities that often involve highly skilled, repetitive movements.
Historically these peculiar postures were considered psychogenic but have now been classified as forms of dystonia. Symptoms may begin with lack of dexterity during performance of a specific motor task with increasingly abnormal posturing of the involved body part as motor activity continues. Initially, the dystonia may manifest only during the performance of the inciting task, but as the condition progresses it may also occur during other activities or even at rest.
Neurological exam is usually unremarkable except for the dystonia-related abnormalities. Although the precise pathophysiology remains unclear, increasing evidence suggests reduced inhibition at different levels of the sensorimotor system.
Symptomatic treatment options include oral medications, botulinum toxin injections, neurosurgical procedures, and adaptive strategies. Prognosis may vary depending upon body part involved and specific type of task affected. Further research may reveal new insights into the etiology, pathophysiology, natural history, and improved treatment of these conditions.
Task-specific dystonias present as focal excessive muscle contractions that develop in parts of the body involved in highly skilled, overlearned tasks such as writing, typing, or playing a musical instrument and occur almost exclusively during the performance of those activities.
