Cervical dystonia, also known as spasmodic torticollis, is a focal dystonia that causes involuntary muscle contractions of the neck and shoulders that result in twisting and/or abnormal postures. Movements are tonic (sustained) and/or clonic (jerky). The disease may be accompanied by pain (over 70% of patients), reduced range of motion, and/or irregular head tremor. The muscle contractions can lead to turning of the head / neck (torticollis), lateral tilting of the head / neck (laterocollis), flexion of the head / neck (anterocollis), and/or extension of the head / neck (retrocollis).

This type of dystonia typically starts after age 30. Symptoms can progress for about 5 years and then typically plateau. Occasionally, affected individuals develop other focal dystonia, but it rarely becomes generalized dystonia. Etiology is often unknown (idiopathic), but it can be secondary to genetic abnormalities or medications.