Facial pain and headache associated with brachial plexus compression in the thoracic inlet.

Among the sources for confusion related to brachial plexus compression in the thoracic inlet are the name for this clinical entity (thoracic outlet syndrome) and the fact that some of its associated symptoms occur outside the upper extremity, such as face and neck pain (FP) and occipital headaches (OH). With the realization that scalenus anticus (SA) contraction is the primary source of brachial plexus compression, it is possible to understand the occurrence of both FP and OH in this syndrome. It was hypothesized that SA contraction compresses the cervical plexus as it exits deep to this muscle. Furthermore, it was hypothesized that tension on the origin of this muscle from the transverse cervical processes causes compression of the occipital nerves. To evaluate this, a consecutive series of 32 patients who had resection of the SA between January 2004 and December 2007 were evaluated to determine prevalence of FP and OH, and the extent to which these symptoms were relieved postoperatively after SA resection. It was found that 25% of the patients had FP and that 50% had OH. Postoperatively, for those patients with neck pain, with or without facial pain, 75% were completely relieved, 18% were partially relieved. OH was completely relieved in 81% and partially relieved in 13% of the patients. In conclusion, symptoms of FP and OH associated with brachial plexus compression is due to cervical plexus compression by SA muscle, and symptoms can be relieved by resection of the SA.