Definition:

Cervical dystonia (CD), formerly referred to as spasmodic torticollis, is a condition characterized by simultaneous and sustained contractions of both agonist and antagonist muscles of the neck, which frequently result in abnormal movements or postures. CD is considered a form of primary adult-onset focal dystonia. The majority of patients complain of pain, which is not a common feature of other focal dystonias. Head rotation is common, but head tilt, neck extension, and flexion may also occur, often in combination. The pathogenesis of primary CD is unclear. Patients with secondary CD may have an abnormal birth or developmental history, exposure to drugs known to cause dystonia (tardive dystonia), or neurological illness. Intramuscular injections of botulinum toxin (BoNT), have been shown to be efficacious and well tolerated when used to treat CD, and are therefore recommended as first-line therapy by current treatment guidelines.