ABSTRACT
The etiology of torticollis remains undefined. Light microscopic evaluation of the involved SCM demonstrates replacement of muscle bundles by dense fibrous tissue. Approximately 25-30 percent of patients presenting with SCM torticollis have a history of breech presentation at birth, with 62 percent involved in a complicated birth. Recent evidence suggests that SCM torticollis may be the manifestation of an in-utero positional disorder with development of an SCM compartment syndrome. Bilateral SCM fibrosis is present in 2-3 percent of cases.
