Neuralgic amyotrophy: clinical features and diagnostic evaluation.
BACKGROUND
Neuralgic amyotrophy is an uncommon neurologic syndrome of unknown etiology involving the brachial plexus, which is manifest by shoulder and arm pain, weakness, and sensory loss. Because of the diversity and variability of the initial features and similarity to other neurologic and non-neurologic disorders, patients may initially present to internists, orthopedic surgeons, or pulmonologists, and may be initially diagnosed with an alternative disorder.


RESULTS
Neuralgic amyotrophy occurs at an annual incidence rate of 1 to 2 cases per 100,000 population. The disorder is most common in adulthood, but patients of any age may be affected. Pain is the most common initial symptom and is followed by weakness and sensory loss in the distribution of a single nerve or diffuse regions of the brachial plexus. Although the exact etiology is unknown, many associated factors, such as immunizations, minor trauma, infectious diseases, pregnancy, and surgical procedures have been associated with the development of the disorder. Evaluation with electrodiagnostic and radiographic studies is useful in confirming the diagnosis and excluding alternative disorders. No treatment has been definitively proven to improve the course of the disorder; however, the overall prognosis is good, with approximately 90% of patients demonstrating significant improvement.


CONCLUSIONS
Neuralgic amyotrophy is an important, potentially debilitating disorder, which may present to physicians in multiple specialties. Awareness of this disorder may preclude unnecessary testing or surgical procedures and can guide toward appropriate treatment with physical therapy. Counseling patients about the overall good prognosis can help appease patients' anxiety about a more sinister diagnosis or course.
Rubin
D I
DI
Department of Neurology, Mayo Clinic, Rochester, Minnesota 55905, USA.