When a person has damage to the peripheral nervous system, this is called peripheral neuropathy. The peripheral nervous system relates to all the nerves that exist outside of the brain and spinal cord. Nerves in the brain and spinal cord are referred to as the central nervous system.
Peripheral neuropathy is complex, and many diseases, injuries, body chemical imbalances, tumors, repetitive motion disorders, exposure to toxins, or genetic inheritance can cause it. It can also vary in symptoms, severity, and rate of cure, depending upon the cause. This damage can have a number of symptoms and can include numbness, tingling, weakness of the muscles the damaged nerves serve, and in some cases severe pain.
If a nerve is permanently damaged, the muscles it serves can gradually die, resulting in movement impairment. In some cases, neuropathy can result in complete paralysis of the affected areas. On the other hand, some conditions cause damage to the nerves temporarily. While people with affected nerves may experience the above conditions on a temporary basis, the nerves are able to recover, so the condition is not permanent.
This is the case with diseases like Guillain-Barre. The condition can cause sudden peripheral neuropathy and temporary paralysis. Many are able to recover from this disease, caused by a virus, and have full movement restored after recovery.
Another disease associated with nerve damage is Lyme disease. Untreated Lyme disease, caused by bites from infected ticks, may result in progressive damage to the peripheral nervous system. Treatment with antibiotics usually is able to stop nerves from becoming permanently damaged.
Autoimmune diseases may result in more permanent peripheral neuropathy, and they may be much more difficult to treat or cure. The chronic inflammation associated with rheumatoid arthritis may also cause some loss of nerve function. Those who suffer from lupus may also suffer a degree of nerve damage as the course of their disease progresses.
In conditions like multiple sclerosis and muscular dystrophy, peripheral neuropathy can cause muscle function to gradually reduce as nerves die off. In severe cases, this damage can significantly impair walking and movement. These conditions are incurable. Congenital abnormalities during development that result in diseases like Charcot-Marie-Tooth cause muscles to die in the lower half of the body, and they also cannot be cured.
Other forms of this condition may be cured when their causes are treatable. Severe lead poisoning or exposure to too much mercury may result in curable cases of peripheral neuropathy, if the cause is found. Correcting hormonal imbalances or vitamin or mineral deficiencies may also arrest further nerve damage. Tumors cutting off nerves may be surgically removed. Many injuries, given appropriate rest, possible surgery, and physical therapy can help end this form of neuropathy, or at least minimize its effects.
Even when cure is possible, some people may have lingering lifetime symptoms like numbness or a slight loss of function in an area where nerves were damaged. In some cases, not all function can be restored, even when treatment of the underlying condition is successful. More understanding of how nerves might recover from paralysis or disease is needed to facilitate full cures in most cases.