The value of muscle biopsy in Myalgia

BACKGROUND- Patients with myalgia are referred to neuromuscular centers for diagnosis and treatment where muscle biopsy is often performed to identify a possible organic or metabolic defect in the muscle. A review of large series that addresses the value of muscle biopsy in myalgia shows a wide range of morphological changes in the muscle (0 to 50%). In this review, I present my experience and that of others to provide a logical framework for the evaluation of such patients. REVIEW SUMMARY- The wide range of abnormalities seen in the muscles in different series of cases is related to selection of patients, interpretation of morphological changes in the muscle, and the extent of studies performed with the muscle tissue, such as ultrastructural studies and enzymes measurement. CONCLUSION- In my series of cases, five patients were found to have primary muscle disease. The present review indicates that for patients with myalgia who have a normal physical examination and laboratory studies, a routine study of muscle tissue does not provide enough information. However, muscle biopsy remains a valuable tool in thoroughly evaluated patients to help identify suspected morphological, biochemical, or ultrastructural abnormalities.