Nerve Damage

What is Nerve Damage?

Your central nervous system plays a part in all physical actions, everything from sensing hot and cold, to feeling when an injury occurs, to breathing.
 
We have three types of nerves:

• Autonomic nerves — These nerves control our background functions that are mostly involuntary: heart rate, digestion, blood pressure, temperature regulation, etc.
• Motor nerves — These nerves control movements and actions by passing information from the brain and spinal cord to our muscles.
• Sensory nerves — These nerves relay information from the skin and muscles back to the spinal cord and to the brain. These are the pain nerves.

Nerve damage, clinically termed peripheral neuropathy when referring to your peripheral nerves, causes numbness, tingling sensations, pain, and eventual weakness, usually in the hands or the feet. Peripheral neuropathy can result due a variety of causes — from traumatic injuries to infections to repetitive motion.

What causes nerve damage?

There are over 100 different types of nerve damage. It’s estimated that 20 million Americans suffer from some type of peripheral nerve damage. These numbers increase as we enter middle age and beyond.

Here are some of the possible causes of nerve damage:

• Trauma/compression– Motor vehicle accidents, sports injuries, falls, and other cases of physical trauma can sever or damage peripheral nerves. Repetitive motion can also cause inflammation of surrounding tissues, leading to nerve compression and future damage.
• Diabetes— Up to 70 percent of people with diabetes suffer from nerve damage. Diabetic neuropathy can affect all three types of nerves.
• Autoimmune diseases– A variety of autoimmune diseases — lupus, multiple sclerosis, Sjogren’s syndrome, rheumatoid arthritis, and others — can cause nerve damage.
• Cancer – Tumors may push against or crush nerves. Or they may create nutritional deficiencies that affect nerve function. Radiation and chemotherapy treatments can damage nerves.
• Drug side effects/toxic substances– Certain medications, such as some chemotherapies for cancer, and toxic substances, such as mercury, can damage the nerves.
• Nutritional deficiencies — Deficiencies in certain nutrients, such as vitamin B12 can cause nerve damage. These can occur due to alcoholism or after gastric surgery.
• Infectious disease— Diseases such as Lyme disease, herpes viruses, HIV, hepatitis C, and others can damage nerves.

Can damaged nerves heal?

Nerves are composed of many fibers, called axons. Axons are separated into bundles within the nerve. A ring of tissue provides kind of insulation and protection around the nerve.
 
While spinal cord nerves cannot heal themselves, peripheral nerves have the ability to regenerate. If both the nerve and the outer insulation are cut, the nerve will need to be fixed to regain function. Otherwise it will for a painful nerve scar, called a neuroma. Sometimes fibers inside the nerve break, but the outer insulation remains intact and healthy. These nerves can heal. The end furthest from the brain will die, but the end closer to the brain will not. New nerve fibers may then grow to replace those that die.

Can severed nerves be repaired?

When a nerve is cut, surgery is required to fix it and allow it to regenerate. This involves sewing the insulation back together at the cut. The goal in fixing a nerve is to save the insulating cover so that new nerve fibers can grow and the nerve can regain function.

If there is a gap where the nerve was severed, it may be necessary to place a nerve graft to fill the gap. This graft needs to come from a donor part of the body, and that area may then have some permanent loss of feeling.

Once the insulating cover is repaired, the nerve generally begins to heal three or four weeks later. Nerves grow about one inch per month, so it can take some time for feeling to return. A sign that the nerve is regenerating after an injury to the wrist, for instance, would be a feeling of pins and needles in the fingertips.

What is a nerve graft?

A nerve graft is a piece of nerve taken from another part of the patient’s body to fill a gap in a severed nerve. A nerve graft can allow the nerve to regenerate and return feeling to the area served by the nerve. However, it may lead to a loss of feeling in the area where the graft was taken from. Donor sites include the back of the calf, front of the forearm, or back of the wrist.

What is a pinched nerve?

A pinched nerve occurs when too much pressure is applied to a nerve by surrounding bones, cartilage, muscles, or tendons. The pressure disrupts the nerve’s function. This is signaled by pain, tingling, numbness, or weakness in the area served by the nerve, such as the hand or shoulder. Most pinched nerves are temporary, as when performing a sport or sleeping in a wrong position, and they can resolve themselves within a few days or weeks. Other pinched nerves, such as compression due to a herniated spinal disk, can be more chronic. Surgery may be required to relieve the point of compression.

When would a person need to see a nerve specialist?

If you’re experiencing any of the symptoms listed above with nerve damage, it’s important to see your primary care physician and then probably a nerve specialist such as Dr. Seruya. This is because if a nerve continues to be compressed over time it can eventually die. If this happens, the person can lose muscle control and function, as there is no longer a nerve to relay signals to the muscle.

If a nerve is severed by trauma, it needs immediate attention to surgically repair it. Again, this demands the expertise of a nerve specialist, such as Dr. Seruya.