Polyneuropathies encompass a wide range of disorders in which the nerves outside of the brain and spinal cord—peripheral to the central nervous system—have been damaged. Polyneuropathy is also referred to as peripheral neuritis or polyneuritis.
Polyneuropathy is a common disorder with many underlying causes. Some of these causes occur frequently, such as diabetes, and others are extremely rare, such as acrylamide poisoning and certain inherited disorders. The most common worldwide cause of polyneuropathy is leprosy. Leprosy is caused by the bacterium Mycobacterium leprae, which attacks the peripheral nerves. According to statistical data from the World Health Organization, an estimated 1.15 million people suffer from leprosy worldwide.
Leprosy is extremely rare in the United States, where diabetes is the most commonly known cause of polyneuropathy. It has been estimated that more than 17 million people in the United States and Europe suffer from diabetes-related polyneuropathy. Many neuropathies are idiopathic, meaning that no known cause can be found. The most common inherited polyneuropathy in the United States is Charcot-Marie-Tooth disease, which affects approximately 125,000 persons.
Another of the better known polyneuropathies is Guillain-Barré syndrome (GBS, acute idiopathic demyelinating polyneuropathy); it is a complication of such viral illnesses, as cytomegalovirus, Epstein-Barr virus, and human immunodeficiency virus (HIV) or bacterial infection, including Campylobacter jejuni and Lyme disease. The worldwide incidence rate is approximately 1.7 cases per 100,000 people annually. Other well-known causes of polyneuropathies include chronic alcoholism, infection, varicella-zoster virus, botulism, and poliomyelitis. Polyneuropathy may develop as a primary symptom, or it may be due to another disease. For example, polyneuropathy is only one symptom of such diseases as amyloid neuropathy, certain cancers, or inherited neurologic disorders. Such diseases may affect the peripheral nervous system (PNS) and the central nervous system (CNS), as well as other body tissues.
To understand polyneuropathy and its underlying causes, it may be helpful to review the structures and arrangement of the PNS.
Barbara Wexler, The Gale Group Inc., Gale, Detroit,