Comparison of acute- and delayed-onset posttraumatic cervical dystonia.

Head, neck, or shoulder trauma is an occasional antecedent event before the appearance of cervical dystonia. A clinically distinctive syndrome of acute-onset posttraumatic cervical dystonia characterized by markedly restricted range of neck motion, absence of phasic involuntary movements, and poor response to treatment has previously been described. Patients with cervical dystonia attending a movement disorder clinic were reviewed for history of trauma before onset of symptoms. Patients with symptom onset within 4 weeks of trauma were compared with patients who developed symptoms between 3 months and 1 year after trauma. Acute-onset cervical dystonia was characterized by markedly reduced cervical mobility; prominent shoulder elevation with trapezius hypertrophy in most patients, absence of involuntary movements, sensory tricks, or activation maneuvers; and poor response to botulinum toxin injection. By contrast, delayed-onset cervical dystonia was clinically indistinguishable from nontraumatic idiopathic cervical dystonia. Acute-onset posttraumatic cervical dystonia is similar to limb dystonia after peripheral trauma and may represent a form of nondystonic muscle spasm similar to torticollis associated with musculoskeletal injuries of the cervical spine and craniocervical junction.