The central nervous system is composed of the brain and spinal cord. The peripheral nervous system extends beyond these structures, allowing nerves to reach the various organs and tissues in order to supply sensory, motor and autonomic nerve function between the brain and the rest of the body. Damage to the peripheral nervous system can cause pain, numbness, muscle weakness and organ dysfunction. Numerous factors can cause damage to the peripheral nerves.
Injury
Trauma to the nerves can be caused by something as extreme as a motor vehicle accident or something as seemingly benign as typing at a keyboard. The National Institute of Neurological Disorders and Stokes explains that sudden trauma can cause nerves to be crushed, stretched or torn, and that in extreme cases nerves can be completely severed from the spinal cord. Automobile accidents, falls, physical altercations and sports injuries can all cause trauma to the peripheral nerves.
Drug Effects
Certain drugs can induce peripheral neuropathy, even when used in accordance with a physician's instructions, according to Professor Richard Hughes of the Department of Neuroimmunology at St. Thomas School of Medicine in London. For example, Cisplatin, a drug approved by the FDA for the treatment of numerous forms of cancer, has been found to cause peripheral neuropathy in up to 29 percent of patients. These side effects can manifest as numbness, tingling and difficulty walking and can increase in severity with continued treatment.
Alcohol is a legal recreational drug that is known to cause neuropathy when used excessively. Chronic alcoholism poisons the nerves, and alcoholism is commonly linked to nutritional deficits that contribute to deterioration of the nerves.
Other Diseases
It is possible for systemic diseases to affect the nervous system in damaging ways. Numerous diseases have been linked to peripheral neuropathy. MedlinePlus lists diabetes, Guillain-Barre syndrome, AIDS and Parkinson's disease among the ailments that can cause damage to the autonomic nerves, which are those that regulate the function of the internal organs.
The sensory and motor nerves can also be affected by disease. Shingles, for example, is associated with pain that travels along the peripheral sensory nerves. Amyotrophic lateral sclerosis, otherwise known as Lou Gehrig's disease, affects motor neurons both in the central and peripheral nervous systems.
Toxin Exposure
Exposure to toxic substances can cause nerve damage. The National Institute of Neurological Disorders and Stokes that heavy metals such as arsenic, lead, mercury and thallium have been associated with neuropathy.
