Dystonia is a movement disorder in which excessive muscle contractions cause abnormal postures, movements, tremor, or a combination of these. Dystonia is often brought out or worsened by specific actions.
Some common forms of dystonia are: blepharospasm (eyes and eyebrows), spasmodic dysphonia (vocal cords, especially while speaking), spasmodic torticollis (head and neck muscles), writer’s cramp (hand, especially while writing), and musician’s dystonia (body parts involved in playing instrument).