Vasomotor, sudomotor, and trophic changes in the skin, with atrophy of the soft tissues and decalcification of bone, may follow the prolonged immobilization and disuse of an arm (i.e., frozen shoulder syndrome) or leg for whatever reason.
Medial and lateral epicondylitis (tennis elbow) are readily diagnosed by demonstrating tenderness over the affected parts and an aggravation of pain on certain movements of the wrist. We have observed entrapment of the ulnar nerve in some cases of medial epicondylitis.
The pain of the carpal tunnel syndrome often extends into the forearm and sometimes into the anterior biceps region and may be mistaken for disease of the shoulder or neck. Similarly, involvement of the ulnar, radial, or median nerves may be mistaken for brachial plexus or root lesions. EMG and nerve conduction studies are helpful in these circumstances (this common disorder is discussed in Chap. 44).
Polymyalgia Rheumatica (See Also Chap. 9)
This syndrome is observed in middle-aged and elderly persons and is characterized by severe pain, aching, and stiffness in the proximal muscles of the limbs and a markedly elevated erythrocyte sedimentation rate. The shoulders are most affected, but half of these patients have hip or neck pain as well. Constitutional symptoms (loss of weight, fever, and anemia) and articular swelling are less consistent manifestations. A few patients have pitting edema of the hands or feet, as illustrated in the review by Salvarini and colleagues; others have knee or wrist arthritis or carpal tunnel syndrome. Arthroscopy and MRI suggest that the pain originates in a synovitis or, sometimes more accurately, a bursitis, and in an inflammation of periarticular structures. The fundamental cause is not known.
Activity of the disease correlates with elevation of the sedimentation rate, almost always above 40 mm/h and typically higher than 70 mm/h (and corresponding elevation of C-reactive protein); unlike the case in polymyositis, with which it is confused, creatine kinase levels are normal. In many patients, polymyalgia rheumatica is associated with giant cell (temporal, or cranial) arteritis. The precise concordance of these two allied conditions is not known but there is not a high frequency of overlap. The arteritis may affect one or both optic nerves; blindness is the main risk of the disease, as discussed in detail in Chap. 13.
Treatment This disorder is self-limiting, lasting 6 months to 2 years, and responds dramatically to corticosteroid therapy, although this may have to be continued in low dosage for several months or a year or longer. We begin treatment with 20 mg of prednisone if there is no evidence of temporal arteritis (which requires higher doses). The absence of improvement in a day or two should bring the diagnosis into question. The degree of hip and shoulder pain is the best guide to the duration of steroid therapy and the rate at which the drug is withdrawn, usually in very small increments every 2 weeks. The sedimentation rate or C-reactive protein can be used as a guide, but neither alone is adequate to alter the medication schedule.
Complex Regional Pain Syndrome (Reflex Sympathetic Dystrophy and Causalgia; (See Chap. 7)