Torsion dystonia is a rare genetic disease featuring painful, involuntary muscle contractions that trigger bodily distortions. There are different types of torsion dystonia, each affecting different parts of the body: cervical dystonia, which affects the spine, head, and neck; spasmodic dystonia, affecting the vocal cords; blepharospasm, affecting the eyelids; oromandibular dystonia, which affects the lips, tongue, and jaw; orofacial-buccal dystonia, otherwise known as Meige’s or Brueghal’s dystonia, which is a combination of oromandibular dystonia and blepharospasm; writer’s cramp, which affects the hand and the forearm; and early-onset torsion dystonia, a severe form of dystonia that begins in the arms or legs and progresses to the rest of the body.
Torsion dystonia, early-onset primary torsion dystonia in particular, primarily affects Jewish individuals of Ashkenazi (Eastern European) descent, although it affects non-Jewish individuals as well.