Diagnosis of peripheral neuropathies.
Interpretive report provided.
48 hours - 3 weeks
Nerve Biopsy kits are available from MLabs and will be required in advance of the procedure. Please notify the MLABS Client Services Center at 800-862-7284 prior to sending specimen. Please complete a Muscle/Nerve/Renal Biopsy Requisition (https://mlabs.umich.edu/media/168) to accompany the specimen.
Advise the surgeon to cut out the entire thickness of the nerve, not a single fascicle and to avoid traumatizing the nerve. The specimen should be 4 cm or longer. Place the specimen on a Tefla pad soaked in saline in a covered container. Wrap the container in paper towels and place on wet ice in a Styrofoam container. Mark "STAT" and send to MLabs immediately. If the specimen cannot be delivered to MLabs within 2 hours, it should be processed in the following manner: Carefully stretch the entire nerve across a piece of dry cardboard or an index card. The nerve will adhere to the dry surface immediately. If glutaraldehyde is available divide the nerve adhered to a cardboard into halves with a sharp blade (avoid teasing!). Cut off the excess of the cardboard and place one piece of the nerve with the cardboard into glutaraldehyde (for plastic embedding and teasing) and the other piece into 10% formalin (for paraffin embedding). If no glutaraldehyde (or other EM fixative) is available cut off the cardboard around the attached nerve and place the nerve with the cardboard in 10% formalin. Label the container with the patient's full name and a 2nd patient identifier. Once the biopsies have been placed in their liquid containers and the tops secured, place inside the ziploc specimen biohazard bag and seal. Wrap the ziploc bag in bubble wrap and place inside transport box. Please be careful to not contaminate the outside of the transport bags, paperwork or box when handling. For detailed collection and shipping instructions, please see https://mlabs.umich.edu/media/572.
Peripheral nerve biopsies at the University of Michigan are processed for light microscopy with special stains, plastic embedding, electron microscopy, and fiber teasing, when this is needed. In the majority of cases, a sural nerve biopsy is sufficient for the diagnosis. However, in the case of pure motor neuropathy, a radial nerve or a branch of peroneal nerve may yield better results.