Cervicogenic headache caused by myofascial trigger points in the sternocleidomastoid: a case report.

Disturbances in the integrity of the upper cervical spine are now well known to be associated with head pain and can give rise to chronic daily headaches (1–3). Head pain that derives from cervical dysfunctions or disease is now contained under the category of cervicogenic headaches (4), which describes a heterogeneous group of disorders that commonly refer pain from structures in the cervical spine region (e.g. joints, muscle, nerve) to various regions in the head. The mechanisms that underlie head pain referred from the neck are not entirely understood. There is general consensus that the trigeminocervical complex, which is located in the lower brainstem and upper three cervical spinal segments and receives multiple afferent inputs from both the trigeminal nerve and cervical peripheral afferents, serves as the centre of convergence for the projection of perceived pain in the head that originates from cervical pain generators (1). However, this model may not explain all forms of cervicogenic pain, in particular myogenic referred head pain that derives from myofascial trigger points (MTrPs) of the cervical and upper back musculature (5, 6). An accurate diagnosis of the aetiology of cervicogenic headache can be challenging for the clinician due, in part, to the overlap of pain and associated symptoms between cervicogenic headache and primary headache (3, 7, 8) and the multiple abnormalities of the cervical spine and musculature that can be a primary source of head pain (9–12). Several authors have emphasized the role of anaesthetic nerve blockade, particularly directed to the occipital nerve and C2 spinal level, as the primary criterion for the diagnosis of cervicogenic headache (1, 3, 13). The increasing attention to anaesthetic blockade as a diagnostic tool has paralleled the expansion of the use of interventional procedures for the treatment of chronic cervicogenic headache (14–16). Interventional diagnostic measures tend to follow from abnormal radiographic findings, such as spondylosis, disk disease or facet arthropathy (1,9), and rely on patient report of diminished pain to anaesthetic challenge as a guide to diagnosis. Increasing reliance on nerve blockade as a diagnostic tool may encourage de-emphasis on the clinical examination of the musculature. Reliance on an interventional approach to the diagnosis of cervicogenic headache that targets joint arthropathies or possible nerve involvement tend to ignore the potential contribution of MTrPs or intersegmental motion restrictions as primary causes of cervicogenic headache (10, 17–19). Identification of the musculoskeletal dysfunctions requires a careful and informed clinical examination. Lack of familiarity with the characteristic myofascial referred pain patterns frequently leads to misdiagnosis and ineffectual headache interventions (10). We report a case of a male with a 25-year history of chronic headaches despite an extensive course of medical evaluations and treatment. After a recent hospitalization and further interventional procedures to identify a cause of his pain, a careful physical examination of the cervical musculature identified MTrPs in the sternocleidomastoid (SCM) muscle as a primary source of his head pain. Physical therapy that focused on reducing the myofascial dysfunction and addressing perpetuating factors felt to be maintaining his MTrP activity brought about dramatic reduction in his pain within 6 weeks, which was maintained at 6 months.