The exact cause of Dystonia is not fully understood. However, regardless of the category or type of dystonia it is believed that the basal ganglia, the portion of the brain which controls movement, is not functioning properly or has been damaged. Diagnosis is usually done by a movement disorder neurologist. An accurate diagnosis requires thorough patient and family history, as well as physical and neurological exams. Additional laboratory, imaging, and genetic tests may be necessary to make a diagnosis.