Biopsy – nerve
A nerve biopsy is the removal of a small piece of a nerve for examination.
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 applies medicine to numb the area before the procedure. The doctor makes a small surgical cut and removes a piece of the nerve. The cut is then closed and a bandage put on it. 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 may 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)
Conditions for which the test may be done include any of the following:
- Alcoholic neuropathy
- Axillary nerve dysfunction
- Brachial plexopathy
- Charcot-Marie-Tooth disease (hereditary)
- Common peroneal nerve dysfunction
- Distal median nerve dysfunction
- Mononeuritis multiplex
- Mononeuropathy
- Necrotizing vasculitis
- Neurosarcoidosis
- Radial nerve dysfunction
- Tibial nerve dysfunction
Normal Results
A normal result means the nerve appears normal.
What Abnormal Results Mean
Abnormal results may be due to:
- Amyloidosis (sural nerve biopsy is most often used)
- Demyelination
- Inflammation of the nerve
- Leprosy
- Loss of axon tissue
- Metabolic neuropathies
- Necrotizing vasculitis
- Sarcoidosis
Risks
- 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 provider about your options.
