During a nerve or muscle biopsy, a sample of nerve or muscle tissue is surgically removed so it can be studied in a laboratory. The procedure is typically done on an outpatient basis using a local anesthetic, although general anesthesia may be necessary in some cases.
Your HonorHealth neurologist may recommend a nerve or muscle biopsy to diagnose or rule out a neuromuscular disorder.
Your doctor may schedule a nerve biopsy if you're experiencing numbness, pain or weakness in your fingers, toes, hands or feet. A nerve biopsy can help your doctor determine whether your symptoms are caused by one of several conditions causing nerve damage, called neuropathies. Before ordering a nerve biopsy your doctor will refer have your nerves tested by an EMG.
Before recommending a muscle biopsy, your physician may first run a series of blood tests and will possibly refer you for an EMG. After completing those tests, a muscle biopsy may still be recommended to evaluate:
How should you prepare for a nerve or muscle biopsy?
Biopsies don't require much preparation. You'll likely have a physical examination during which you'll give your medical history including a list of any prescription medications, over-the-counter medicines and/or supplements. Your doctor may have you stop taking certain pain relievers, supplements or blood thinners for a short period prior to your procedure.
You should refrain from eating and drinking eight hours before your biopsy and will want to arrange for someone to drive you home.
What can you expect during a nerve or muscle biopsy?
Biopsies are relatively simple procedures. You'll typically go home the same day and will quickly resume your routine activities.
- Nerve biopsy procedure: The biopsy site will be numbed with a local anesthetic, which may burn or sting at first. The physician will make a small incision, usually in your ankle or calf, and remove a small portion of your nerve. You'll likely have a few stitches at the biopsy site, but they'll be absorbed by your body and won't need to be removed.
- Muscle biopsy procedure: The biopsy site will be numbed with a local anesthetic, which may burn or sting at first. The physician will make a small incision. This is usually in your thigh or upper arm (bicep), but other muscles may be tested as your condition indicates. One to three small pieces of muscle will be removed. You won't notice any subsequent change in muscle function. You'll probably have a few stitches at the biopsy site, but they'll be absorbed by your body and won't need to be removed.
What should you expect after a biopsy?
You'll receive instructions on how to care for your incision site — keeping the area covered, clean and dry.
The lab typically performs a few basic tests and, based on the results, may run additional tests. Your report will typically be available within two weeks of your biopsy. You'll want to discuss the results with your physician, especially next steps and/or treatment options.
- Nerve biopsy: After the procedure, the area may feel tender or sore for a few days. The area around the biopsy site could remain numb for six to 12 months, perhaps even permanently. But because the location is very small, you may barely notice it.
- Muscle biopsy: You may be sore for about a week.