Dystonia

Dystonia (literally, "abnormal muscle tone") is a term used to describe a movement disorder involving involuntary, sustained muscle contractions. Dystonia and Parkinson's disease together are the most common movement disorders in the developed world, affecting an estimated 800,000 people in North America, and at least 90,000 people in Australia.  At present, there are no known therapies that arrest the progression of these neurodegenerative diseases.