Nerve Biopsy

Peripheral nerve biopsy is a valuable tool for detecting pathomorphological changes in certain patients with neuropathy.

Given the invasiveness of the procedure, biopsy is considered the final step in the instrumental diagnostic workup. The sural nerve or the superficial branch of the radial nerve is typically taken as the biopsy specimen.

Biopsy may be useful in CIDP, transthyretin amyloid neuropathy, sarcoidosis, leprosy, and rare neuropathy caused by silver poisoning. In patients with diabetes mellitus (DM), biopsy should be avoided because of possible complications related to the underlying disease.

Skin biopsy with determination of C-fiber density is indicated for patients with clinical signs of small fiber neuropathy and is performed to detect the condition itself rather than its etiology. This method shows high sensitivity — up to 90%. Biopsy of other tissues, such as the salivary gland, is performed when Sjögren's syndrome is suspected; biopsy of anterior abdominal wall fat tissue, oral mucosa, or rectum is informative in amyloidosis, and of lymph nodes in sarcoidosis.

Text author: Dmitry S. Druzhinin, MD, DSc