The Importance of Muscle and Nerve Biopsies in the Diagnosis of Neuromuscular Diseases

Evaluation of muscle and nerve biopsy samples is an important diagnostic tool in patients with neuromuscular disease. It can be thought that the great developments in the field of medicine in recent years have reduced the importance of these investigations. However, histopathological examination narrows the genetic diseases panel to be applied in differential diagnosis by reducing possible diagnostic options, especially in the first approach. It also provides information about the severity of the disease that cannot be distinguished by genetic examination in the most frequently seen X-linked dystrophinopathies. It distinguishes inflammatory, metabolic, and mitochondrial diseases that can be confused with hereditary myopathies clinically. In some cases, the differential diagnosis approach is only made with repeated biopsy samples. As a result of the change in the concept of inflammatory neuropathy in nerve biopsies, evaluation of nerve biopsy is very important in the diagnosis of inflammatory neuropathy and in addition to grading myelin loss or axonal degeneration. In this review, it is aimed to emphasize with case examples the conditions where muscle and nerve biopsies are very important.