PERIPHERAL NEUROPATHY

Peripheral Neuropathy

Peripheral Neuropathy

Background

Peripheral neuropathy is a general term referring to disorders of peripheral nerves. The peripheral nervous system is made up of the nerves that branch out of the spinal cord to all parts of the body. Neuro means nerves. Pathy means abnormal. Peripheral neuropathy is very common. Because there are numerous types and causes of neuropathy and scientists do not always agree on the same definition of neuropathy, the exact incidence cannot be precisely determined. Peripheral neuropathy can be associated with poor nutrition, a number of diseases, and pressure or trauma. Many people suffer from the disorder without ever identifying the cause. Peripheral neuropathy affects at least 20 million people in the United States. Nearly 60 percent of all people with diabetes suffer from peripheral neuropathy.

Peripheral neuropathy may involve damage to a single nerve or nerve group (mononeuropathy) or may affect multiple nerves (polyneuropathy). Mononeuropathies may be due to entrapment, compression, stretch injury, ischemia, infection, or inflammation of a nerve. Polyneuropathies are relatively symmetric, often affecting sensory, motor, and vasomotor fibers simultaneously.

More than 100 types of peripheral neuropathy have been identified, each with its own characteristic set of symptoms, pattern of development, and prognosis. Impaired function and symptoms depend on the type of nerves—motor, sensory, or autonom-ic—that are damaged. Motor nerves control movements of all muscles under conscious control, such as those used for walking, grasping things, or talking. Sensory nerves transmit information about sensory experiences, such as the feeling of a light touch or the pain resulting from a cut. Autonomic nerves regulate biological activities that people do not control consciously, such as breathing, digesting food, and heart and gland functions. Although some neuropathies may affect all three types of nerves, others primarily affect one or two types.

Risk factors signs and symptoms

Peripheral neuropathy may be either inherited or acquired. Causes of acquired peripheral neuropathy include physical injury (trauma) to a nerve, tumors, toxins, autoimmune responses, nutritional deficiencies, alcoholism, and vascular and metabolic disorders. Acquired peripheral neuropathies are grouped into three broad categories: those caused by systemic disease, those caused by trauma from external agents, and those caused by infections or autoimmune disorders affecting nerve tissue. In some cases, the cause is an earlier viral infection, pressure on the nerve from a tumor or swollen blood vessel, or infrequently, multiple sclerosis. In many cases, however, a specific cause cannot be identified. Doctors usually refer to neuropathies with no known cause as idiopathic neuropathies.

Physical injury (trauma) is the most common cause of injury to a nerve. Injury or sudden trauma, such as from automobile accidents, falls, and sports-related activities, can cause nerves to be partially or completely severed, crushed, compressed, or stretched, sometimes so forcefully that they are partially or completely detached from the spinal cord.

Systemic diseases, disorders that affect the entire body, often cause peripheral neuropathy. These disorders may include metabolic and endocrine disorders. Nerve tissues are highly vulnerable to damage from diseases that impair the body's ability to transform nutrients into energy, process waste products, or manufacture ...