Diagnosis of dystonia

Dystonia is a movement disorder characterized by patterned, directional, and sustained muscle contractions that produce abnormal, often twisting, postures or repetitive movements. Dystonia can result from a wide variety of causes, and clinicians must endeavor to elucidate its etiology in every patient in order to tailor optimal counseling and therapy for each individual. Although our understanding of the basic pathophysiologic mechanisms that give rise to this condition remains incomplete, thanks to advances in fields as disparate as neuroimaging and molecular genetics, modern diagnostic testing permits a specific diagnosis to be applied in many patients with dystonia. This chapter will present one diagnostic approach to patients with dystonia.