Nerve biopsy is the removal
of a small piece of nerve for examination. Through a small incision, a sample of
nerve is removed and examined under a microscope. Nerve biopsy may be performed
to identify nerve degeneration, identify inflammatory nerve conditions
(neuropathies), or to confirm specific diagnoses.
Biopsy - nerve
A nerve biopsy is the
removal of a small piece of a nerve for examination.
How the test is performed
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.
How to prepare for the
There is no special
How the test will feel
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.
Why the test is performed
Nerve biopsy may be
performed to help distinguish between demyelination
(destruction of parts of the myelin sheath covering the
nerve) and axon degeneration (destruction of the axon
portion of the nerve cell), to identify inflammatory nerve
conditions (neuropathies), or to confirm specific diagnoses.
There is normal nerve
anatomy, with no abnormal growths or inclusions.
What abnormal results mean
Conditions or disorders
that may be revealed include:
Additional conditions under which the test may be
Axillary nerve dysfunction
Charcot-Marie-Tooth disease (hereditary)
Common peroneal nerve dysfunction
Distal median nerve dysfunction
Radial nerve dysfunction
Tibial nerve dysfunction
What the risks are
Permanent nerve damage (uncommon; minimized by careful
Discomfort after the procedure
Infection (a slight risk any time the skin is broken)
Allergic reaction to the local anesthetic
Nerve biopsy is invasive
and is useful only in certain circumstances. These include
diagnosis of asymmetric and multifocal nerve disorders,
conditions in which a nerve is palpably enlarged (the
enlargement can be felt with the fingers), and suspected
inherited pediatric nerve disorders.