A nerve biopsy is the removal of a small piece of a nerve for examination.

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)

The sural nerve (in the ankle), or the superficial radial nerve (wrist) are the sites most often used for biopsy. A local anesthetic is used to numb the area. A small incision is made, and a portion of the nerve is removed. The sample is then examined using either a regular (light) microscopic or an electron microscope. Individual nerve fibers may also be examined.

There is no special preparation.

The amount of pain during and after the procedure depends on the patient. Because a local anesthetic is used, discomfort during the procedure is usually minimal. The anesthetic may burn or sting when first injected. After the procedure, the area may feel tender or sore for a few days.