Nerve Transfer

Nerves are the “wires” that carry messages between the brain and the rest of body. “Sensory nerve” carry messages about “sensation” — pain, temperature, vibration, and pressure. “Motor nerves” carry messages to muscles to to instruct them to move. Nerves contain bundles of smaller “fascicles” and may contain both sensory and motor nerves.

When someone sustains a nerve injury, the nerve is no longer able to transmit a signal to or from the brain. Sometimes, this can be treated with a nerve repair or nerve graft. However, a nerve transfer may be necessary in certain scenarios, such as when part of the injured nerve is no longer available for reconstruction or when the length of the nerve injury is so long that nerve grafting would not provide a good outcome.

Nerve transfer is a technique where healthy, uninjured nerves are cut and transferred into the nerves for affected muscles that no longer have a connected functional nerve. This transferred nerve can then be used to control the new muscle into which it was transferred. When performing a nerve transfer, the function lost by cutting the nerve typically has redundant function performed by another muscle, or the lost function is considered less important that the function that the transfer is intended to restore.

Situations in which a nerve transfer might be considered include a peripheral nerve injury, brachial plexus injury, spinal cord injury, or certain types of nerve compression syndromes such as cubital tunnel syndrome.

The initial evaluation depends on the underlying nerve condition such as a peripheral nerve injury, brachial plexus injury, spinal cord injury, or certain types of nerve compression syndromes such as cubital tunnel syndrome. If a nerve transfer is a consideration for treatment, then your surgeon will discuss potential donor nerves. This will include an assessment of the function of the potential donor nerve and a discussion of the trade-offs associated with transferring the donor nerve.

When nerve transfer is performed, there is a healthy, normal “donor nerve” going into a muscle and an injured “recipient nerve”. The donor nerve is cut and repaired to the recipient nerve. Often, nerve transfer surgery can be performed as an outpatient with same day surgery. For larger injuries and more extensive transfers, an overnight stay may be needed.

If too much time has passed after the nerve injury, then the “neuromuscular junctions” (NMJ), where the nerve enters into the muscle, may degenerate. If this happens, then it is not possible for nerve function to return to the affected muscle, and instead, alternative reconstructive strategies such as tendon transfers are necessary. For this reason, it is important to seek treatment as soon as possible after a nerve injury.

As the donor nerve regenerates, it will grow into the recipient nerve and eventually into the affected muscle or skin. Nerve growth usually proceeds at one millimeter per day or one inch per month, although this is dependent on other factors such as the type of injury, age of the patient, and associated medical conditions.

While the nerve is healing, there may be an uncomfortable “pins and needles” sensation. Hand therapy may be necessary to help with “motor re-education” as the brain learns that the donor nerve no long controls the muscle that it naturally controlled but now instead controls the new muscle to which it was transferred.

Final recovery may take several months or longer depending on the distance required for nerve growth. The amount of recovered sensory or motor function depends on variety of factors, including the specific nerve injured and the distance of the injured nerve to its targets.

Be sure to see an experienced surgeon to treat this condition. Our fellowship-trained specialists at The Buncke Clinic in San Francisco treat patients needing nerve transfers from across the Bay Area and Northern California. Contact us to schedule a consultation.