| Subject | Contents |
| Definition | A nerve biopsy is the removal of a small piece of nerve(s) for examination. |
| Alternative Names | Biopsy - nerve |
| How the test is performed | The sural nerve (in the ankle), or the superficial radial nerve (wrist) are the sites most often used. 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 test | Adult: There is no special preparation. Infants and children: The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experience, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:Infant test or procedure preparation (birth to 1 year) Toddler test or procedure preparation (1 to 3 years) Preschooler test or procedure preparation (3 to 6 years) Schoolage test or procedure preparation (6 to 12 years) Adolescent test or procedure preparation (12 to 18 years) |
| How the test will feel | 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 myelination '>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. |
| Normal Values | There is normal nerve anatomy, with no abnormal growths or inclusions. |
| What abnormal results mean | Conditions or disorders that may be revealed include:Necrotizing vasculitisAmyloidosis (sural nerve biopsy is most often used) SarcoidosisLeprosyMetabolic neuropathiesInflammation of the nerve Loss of axon tissue Demyelination Additional conditions under which the test may be performed: Alcoholic neuropathyAxillary nerve dysfunctionBrachial plexopathyCharcot-Marie-Tooth disease (hereditary)Common peroneal nerve dysfunctionDistal median nerve dysfunctionMononeuritis multiplexMononeuropathy Necrotizing vasculitis NeurosarcoidosisRadial nerve dysfunctionTibial nerve dysfunction |
| What the risks are | Permanent nerve damage (uncommon; minimized by careful site selection) Discomfort after the procedure Infection (a slight risk any time the skin is broken) Allergic reaction to the local anesthetic |
| Special considerations | 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), confirmation of disorders involving the nerves when the needed information is not otherwise available, and suspected inherited pediatric nerve disorders. |
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