Your doctor will ask if you've been hurt or had surgery recently, look at your medical records, and talk to you about how you're feeling right now. In addition, your doctor will check your nervous system and do a physical checkup. If your neurological exam shows signs of a nerve injury, your doctor may suggest diagnostic tests, such as:
- Electromyography (EMG). An electromyogram (EMG) measures the electrical activity of a muscle while it is at rest and in motion using a small needle electrode placed into the muscle. Muscle weakness may be an indication of nerve damage.
- Nerve conduction study. Scientists can determine how sound electrical signals travel through the nerves by putting electrodes in two different body parts.
- Magnetic resonance imaging (MRI). MRI uses a magnetic field and radio waves to get clear pictures of nerve-damaged areas.
- Like MRI, these high-frequency sound waves give detailed images of the area affected by nerve injury.
Nerve Injuries
Upper (hand, arm, and shoulder) and lower (leg and foot) extremity nerve injuries are more common than those in the middle of the body. Sharp trauma, such as that which results from a straight cut from a knife, can be just as devastating as blunt trauma, such as that which results from a fall or the traction injuries occurred in car crashes. An expert evaluation and treatment plan are necessary for severe nerve damage. If the nerve is still partially intact, recovery may be possible with careful observation and time. These injuries, however, almost always necessitate surgical reconstruction.
Diagnosis
Sensory and motor function in the injured nerves will be evaluated first to determine the extent of the patient's injury. After a diagnosis of damage and severity has been made, further examination with nerve conduction tests and electromyography may be performed (EMG). These tests help the neurologist pinpoint the exact site and severity of the injury by measuring the electrical activity of the nerves and muscles. An MRI scanner can sometimes be used to take pictures of nerves. Electrical investigations could be repeated every two months to check for evidence of improvement. When this stage of healing has been reached, surgical reconstruction is usually required.
Surgical Repairs
To repair a damaged nerve, surgeons must first locate the nerve and remove any scar or damaged tissue from the nerve's ends. After that, if the nerve ends are long enough, a direct reconnection can be made with minimal tension. The bundles (groups of fibers) inside the damaged nerve are realigned with the help of an operating microscope. When more tissue needs to be taken away from nerve endings, the space left behind can sometimes stop the nerves from healing directly.
When this occurs, a non-essential nerve from another body part (often the leg or upper arm) is removed to serve as a makeshift nerve. Nerve grafting is the term used to describe this operation. In rare cases where grafting is not an option, other ways to fix the nerve damage may be used, such as a conduit or an artificial tube connecting the nerve ends. Some patients may also do better without nerve grafting if they use nerve graft substitutes from a donor's nerve tissue.
As soon as a damaged nerve is restored, new fibers begin to grow in that direction, eventually reaching the skin and severed muscle. This happens at a rate of about 1mm per day (1 inch per month) for weeks to months until the nerves reach their destination. When a nerve is repaired, there will be a sensitive spot that will tingle when tapped. This shows that the nerve is healing. The nerve's progressing fibers are those that are still healing.
After nerve repair, patients will be tested often to see how these nerve fibers are doing as they grow back. The person will do physical therapy to keep their muscles and joints mobile and flexible while the nerve heals. A therapist will begin exercises to strengthen the patient's muscles and restore voluntary mobility once the patient exhibits healing symptoms, such as regaining muscular tone and contraction. Once the feeling returns, the therapy will also focus on teaching the patient how to use their sense of touch again.
For some nerve injuries, nerve restoration alone won't be enough to get you back on your feet because the damage to the nerve is too far from the muscles that were hurt. Reconstructive surgeries to restore lost function are an option in certain circumstances.
Tendon transfer methods use healthy muscles next to a paralyzed one and attach the tendons from the healthy muscle to the injured one. This lets the healthy muscle move in place of the injured one. After the tendons have healed, therapy will begin so the patient can learn how to use the transferred muscle.
A nerve transfer is a surgical operation in which healthy nerve branches from a nearby nerve that has not been damaged are rejoined to a nerve that has been damaged near its muscle connection. When performed early enough, nerve transfers can restore muscle function by relocating regenerating nerve ends close to the affected muscles.
Similar to traditional nerve repairs, therapy is begun once the nerve has healed to enhance functional improvements. One more method that can help restore sensation involves moving nerve fibers from healthy sensory nerves to those damaged or dead.