One would suppose that these patients with chronic pain could be subdivided into a group with continued radicular pain and another with referred pain from disease of the spine. However, once the pain becomes chronic, the separation is not easy. Pressure over the spine, buttock, or thigh may cause pain to be projected into the leg. Lidocaine blocks of nerve roots have yielded inconsistent results. Transcutaneous stimulators, posterior column stimulators, intrathecal injections of analgesics, and epidural steroid injections have seldom helped for long in our experience, but we have seen striking exceptions, especially with epidural pumps that administer analgesics. At present, the best that can be offered the patient is weight reduction (in appropriate individuals), stretching and progressive exercise to strengthen abdominal and back muscles, as well as mild nonnarcotic analgesics and antidepressant drugs. A trial of epidural steroid injection, physiotherapy or a limited course of spinal chiropractic manipulation is reasonable.
PAIN IN THE NECK, SHOULDER, AND ARM
It is useful to distinguish three major categories of painful disease of the neck and arms—that originating in the cervical spine, in the brachial plexus, and in the shoulder. Although the distribution of pain from each of these sources may overlap, the patient can usually indicate its site of origin. Pain arising from the cervical part of the spine is felt in the neck or back of the head and is projected to the shoulder and upper arm; it is evoked or enhanced by certain movements or positions of the neck and is accompanied by limitation of motion of the neck and by tenderness to palpation over the cervical spine.
Pain of brachial plexus origin is experienced in the supraclavicular region, or in the axilla and around the shoulder; it may be worsened by certain maneuvers and positions of the arm and neck (extreme rotation). A palpable abnormality above the clavicle may disclose the cause of the plexopathy (aneurysm of the subclavian artery, tumor, cervical rib). The combination of circulatory abnormalities and signs referable to the medial cord of the brachial plexus is characteristic of the thoracic outlet syndrome, described further on.
Pain localized to the shoulder region, worsened by motion, and associated with tenderness and limitation of movement, especially internal and external rotation and abduction, points to a tendonitis, subacromial bursitis, or tear of the rotator cuff, which is made up of the tendons of the muscles surrounding the shoulder joint. The term bursitis is often used loosely to designate these disorders. Shoulder pain, like spine and plexus pain, may radiate vaguely into the arm and rarely into the hand, but sensorimotor and reflex changes—which always indicate disease of nerve roots, plexus, or nerves—are absent. Shoulder pain of this type is very common in middle and late adult life. It may arise spontaneously or after unusual or vigorous use of the arm. Local tenderness over the greater tuberosity of the humerus is characteristic. Plain radiographs of the shoulder may be normal or show a calcium deposit in the supraspinatus tendon or subacromial bursa. MRI is able to demonstrate more subtle abnormalities, such as muscle and tendon tears of the rotator cuff or a labral tear of the joint capsule. In most patients the pain subsides gradually with immobilization and analgesics followed by a program of increasing shoulder mobilization. If it does not, the injection of small amounts of corticosteroids into the bursa, or the site of major pain indicated by passive shoulder movement in the case of rotator cuff injuries, is often temporarily effective and allows the patient to mobilize the shoulder. The problem of the “frozen shoulder” is addressed further on.