What Is Nerve Injury?
Nerves are responsible for transmitting signals that control many vital functions, including touch, pain, and movement. They are cable-like structures that send and receive messages between the brain to the rest of the body. Sensory nerves transmit signals from the skin, muscles, and other organs and relay them to the brain, where they are received and interpreted. Motor nerves travel from the brain to the muscles to control purposeful movements. Consequently, when a nerve is damaged or cut, the affected area can experience a partial or total loss of function and/or feeling. Left untreated, this can result in a complete inability to perform simple tasks or work-related duties, particularly if the injured nerves control hand or wrist motion. Living with an injured nerve can be very debilitating and lead to a diminished quality of life, making it crucial to seek proper care from a reconstructive hand surgeon as soon as symptoms begin to arise.
Signs & Symptoms
The symptoms of an injured nerve vary depending on the type of nerve that was damaged and the severity of the injury. However, in general, common signs of a nerve injury include:
- Nerve Pain/Paresthesias—A damaged nerve is often accompanied by sharp or aching pain at the point of injury. Burning pains, a pins and needles feeling, or electric shock-like sensations can travel anywhere up and down the length of the nerve.
- Numbness—Because nerves provide sensory function, an injured nerve usually causes partial or complete numbness in the affected body part.
- Weakness—Nerves also significantly impact motor function. When excessive pressure is placed on a nerve and it becomes injured, this stress disrupts the motor signals sent by the brain and the affected muscles can become weak.
These symptoms can be felt constantly, intermittently, or solely when stretching the nerve or performing certain actions. Nerve-related symptoms can be vague and are often difficult to put into words. Ultimately, symptoms differ by patient and we offer many treatments to address each individual’s unique condition.
Causes
A nerve injury can result whenever there is too much pressure placed on the nerve, or the nerve is stretched or cut. This trauma disrupts the messages that are sent from the brain and can impede motion, function, and sensation. The amount of function that is lost, as well as the expected recovery, depends on the degree of injury to the individual nerve fibers. Penetrating injuries with a saw, knife, or glass anywhere in the arm can result in a nerve injury. Motor vehicle or motorcycle accidents can result in severe stretching of the nerves, or complete cutting of a nerve associated with a broken bone or broken glass. Crushing injuries can result in temporary or permanent nerve loss from pressure. Evidence is mixed about the association between nerve injury or dysfunction and some work-related activities, such as typing or light office work. Heavy vibrational activities or repetitive, stressful motions can result in chronic nerve compression like carpal tunnel syndrome.
Treatment
Some minor nerve damage will heal without intervention, but other more severe injuries—such as a cut nerve—typically require surgery. It is possible for damaged nerve fibers to regrow and allow for continued communication between the brain and body, but this process can take several months and will likely involve rehabilitative hand therapy or another form of supportive care.
When a nerve is completely severed, surgery from one of our reconstructive hand surgeons will be utilized to carefully sew the nerve endings back together using special magnification and fine hair-like sutures to allow for regrowth to the muscle or skin. Depending on the details of your injury, this can help the area regain function and sensation. Nerve injuries have a varied potential for recovery based on the location, severity, and age of the patient. Our expert hand surgeons will take the time to educate you on the details of your injury and formulate a plan that will maximize your potential for recovery.
Secondary Reconstruction
Sometimes, the function lost with complex nerve injuries must be repaired or replaced by other means in order to truly restore lost function and/or sensation in a given region. This may involve replacing the damaged nerve with nerves from a less critical part of the body. For example, “donor nerves” can come from the side of the foot or another area that is deemed non-essential. Secondary reconstruction of a nerve can be accomplished in a variety of ways, including:
- Nerve grafting: Nerve grafting is a surgical technique that uses a donor nerve from another part of the body to bridge or replace a gap in an injured nerve. The donor nerve is typically considered less important in its original location than the nerve that is being repaired. Processed cadaver nerves can also be used in many instances to eliminate any donor site problems.
- Nerve transfers: A nerve transfer restores function by completely replacing an injured nerve with another nerve in close proximity to the target muscle or sensory area. The transferred nerve is “plugged” into the location of the injured nerve, and eventually the area is able to receive messages about sensation and function from the brain again.
- Tendon transfers: When restoring the actual nerve input to an area is not possible, a tendon transfer is typically used to restore muscle function to a given area. It involves removing the end of a non-essential tendon, and transferring it to another location to perform another function. This technique is useful when the nerve can no longer be repaired, or the window for successfully repairing a nerve has passed.
In some cases, an injury to a sensory nerve can cause a painful knot of nerve tissue to form — this is called a neuroma. Surgery can also be utilized to remove the nerve tissue and provide relief for painful symptoms caused by a neuroma.
Nerve injuries are extremely complex and each case is different. The most beneficial approach to address your injury is typically chosen based on which technique offers the strongest chance of recovering function. Any surgery performed on the nerves is typically followed by a gradual recovery period while the damaged nerves regrow. Physical therapy after the operation can aid in the healing process and often helps individuals relearn new patterns of motion to minimize pressure on the treated nerve. While nerve injuries can be difficult to live with, our experienced hand surgeons can provide you with the necessary care to repair your injury and enhance your overall quality of life.
