People with dystonia experience involuntary muscle spasms or contractions. These result in twisting or jerking movements, and unusual body positions/postures. Dystonia can affect almost any part of the body, however, only one area is often affected.
The common presentations are:
• Facial muscle contractions resulting in excessive blinking or eye lid spasms, called blepharospasm. When this occurs together with lower facial spasms, it is referred to as Meige syndrome. Involuntary muscle spasms or contractions of the jaw and/or tongue are known as oromandibular dystonia.
Please visit the following sites for more information:
Dystonia Fact Sheet (NINDS)