Entrapment neuropathies of the upper extremity are common problems. A wide range of physicians, from primary care providers to specialists such as orthopedic surgeons, plastic surgeons, or neurosurgeons, are sought to care for these problems.
What has traditionally been attributed to features of normal aging (eg, weakness, loss of function or sensation) has been subsequently recognized in younger patients whose vocations require repetitive motion to complete work-related tasks. Repetitive motion, force, posture, and vibratory influences on the peripheral nerves of the upper extremity are poorly understood but are blamed as contributing factors to the development of neuropathic symptoms.
Currently, patterns of symptomatology, objective measures of nerve function (eg, electromyelogram [EMG] evaluation, nerve conduction studies), and the anatomy associated with nerve compression have been well outlined. Despite attempts at conservative medical and functional management, surgical decompression has become the choice for definitive treatment.
Many of the findings of peripheral nerve irritation or entrapment are identified during the physical examination and are discussed here in relation to each of the individual syndromes. Reproducing symptoms via provocative maneuvers or diagnosing deficits in strength or sensation can be accomplished in the office or with the aid of hand therapists.
Two-point discrimination testing, Semmes-Weinstein monofilament testing, and grip strength measurements are simple and inexpensive means of evaluation. Findings from imaging studies (eg, plain radiographs, MRIs) are occasionally helpful for excluding cervical ribs, lung tumors, or extremity masses, which may be contributing to neural compression.
Electrodiagnostic studies (eg, EMG, nerve conduction studies) remain the criterion standard for objective evaluations of neuropathic conditions. These studies are not without flaws; they are highly operator-dependent and the results do not always correlate with the severity of symptoms or patient outcomes. Despite these drawbacks, they may help confirm equivocal physical examination findings or help isolate the specific site of compression preoperatively. EMGs also may be used to verify progression or resolution in neurophysiology following surgical release.