Differential treatment of sternocleidomastoid and longus colli muscles in anterocollis patients with and without anterior shift

Anterocollis may be caused by dystonic contractions of superficial and deep cervical muscles. Scalene, digastric, omohyoid muscles and platysma are supposed to be main players in anterocollis. Longus colli, longus capitis and sternocleidomastoid muscles have also been implicated in that difficult to treat form of cervical dystonia. Bilateral BoNT-A injection of sternocleidomastoids, however, is often ineffective and may be complicated by dysphagia. Therefore individual anatomical and biomechanical contributions of the anterior cervical muscles to the complex dystonic action in anterocollis need to be evaluated i…