A nerve biopsy is the removal of a small piece of a nerve for examination.
Biopsy - nerve
How the Test is Performed
A nerve biopsy is most often done on a nerve in the ankle, forearm, or along a rib.
The health care provider will apply medicine to numb the area before the procedure. The doctor makes a small surgical cut and removes a piece of the nerve. The nerve sample is sent to a lab, where it is examined under a microscope.
How to Prepare for the Test
There is no special preparation.
How the Test Will Feel
When the numbing medicine (local anesthetic) is injected, you will feel a prick and a mild sting. The biopsy site will be sore for a few days after the test.
Why the Test is Performed
Nerve biopsy may be done to help diagnose:
- Axon degeneration (destruction of the axon portion of the nerve cell)
- Damage to the small nerves
- Demyelination (destruction of parts of the myelin sheath covering the nerve)
- Inflammatory nerve conditions (neuropathies)
Additional conditions under which the test may be performed:
- Alcoholic neuropathy
- Axillary nerve dysfunction
- Brachial plexopathy
- Charcot-Marie-Tooth disease (hereditary)
- Common peroneal nerve dysfunction
- Distal median nerve dysfunction
- Mononeuritis multiplex
- Necrotizing vasculitis
- Radial nerve dysfunction
- Tibial nerve dysfunction
A normal result means the nerve appears normal.
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
Abnormal results may be due to:
- Amyloidosis (sural nerve biopsy is most often used)
- Inflammation of the nerve
- Loss of axon tissue
- Metabolic neuropathies
- Necrotizing vasculitis
What the Risks Are
- Allergic reaction to the local anesthetic
- Discomfort after the procedure
- Infection (a slight risk any time the skin is broken)
- Permanent nerve damage (uncommon; minimized by careful site selection)
Nerve biopsy is invasive and is useful only in certain situations. Talk to your doctor about your options.
Shy ME. Peripheral neuropathies. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier. 2007: chap 446.
Vallat, JM, Funalot, B, and Magy, L. Nerve biopsy: requirements for diagnosis and clinical value. Acta Neuropathol 2011, 121: 313-326.
Last reviewed 5/28/2013 by Luc Jasmin, MD, PhD, FRCS (C), FACS, Department of Neurosurgery at Cedars-Sinai Medical Center, Los Angeles CA; Department of Surgery at Los Robles Hospital, Thousand Oaks CA; Department of Surgery at Ashland Community Hospital, Ashland OR; Department of Surgery at Cheyenne Regional Medical Center, Cheyenne WY; Department of Anatomy at UCSF, San Francisco CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.
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