Surgical treatment of compressive cervical band.

Compression of the lower portion of the brachial plexus by a cervical band continuous with the scalenus medius is a rare but well-defined cause of arm pain. The syndrome should be suspected in a patient who presents with chronic arm pain and thenar atrophy. Cervical ribs or prominent C-7 transverse processes will be present on an anteroposterior roentgenogram of the cervical spine, and the diagnosis is confirmed by characteristic electromyographic findings. The syndrome should be differentiated from other causes of chronic arm pain, such as herniated cervical disc, syringomyelia, spinal cord tumor, or carpal tunnel syndrome. The condition is readily treated by surgical division of the compressive band, approached through a supraclavicular incision.