Dystonia symptoms may follow trauma to the head, and/or trauma to a specific body area.
Dystonia symptoms following head trauma often affect the side of the body which is opposite to the side of the brain injured by the trauma. Examples of peripheral injury include oromandibular ystonia following dental procedures, blepharospasm following surgery or injury to the eyes, and cervical dystonia following whiplash or other neck injury. Symptoms of trauma-induced dystonia may be paroxysmal (meaning that they occur in episodes or attacks of symptoms), not respond to sensory tricks, and persist during sleep.
Brain trauma will often manifest in observable lesions in the brain that can be assessed by neuroimaging techniques. Onset of symptoms may be delayed by several months or years after trauma. Clues to whether dystonia to a specific body part can be attributed peripheral injury to that body area include:
- The injury is severe enough to cause local symptoms that persist for at least two weeks or require medical evaluation within two weeks;
- The onset of the movement disorder occurs within days or months (up to a year) after the injury;
- The symptoms relate anatomically to the injured part of the body.
In addition to dystonia, movement disorders that are believed to result from brain and peripheral trauma include parkinsonism, tremors, chorea, myolconus, tics, and hemifacial or hemimasticatory spasm.