About Peripheral Neuropathy
Peripheral neuropathy is a term used to describe damage to nerves of the peripheral nervous system, which leads to symptoms such as pain, numbness, tingling, burning, and weakness. Peripheral neuropathy most commonly affects the peripheral limbs, namely hands, arms, feet and legs. Peripheral neuropathy can be caused by a variety of precipitating factors including trauma, infection, metabolic disorders (e.g., diabetes), alcohol abuse, and cancer chemotherapy. It can also be idiopathic, meaning that it arises from an unknown cause.
Peripheral neuropathy develops as a result of injury or damage to any of the three types of nerves in the peripheral nervous system. Symptoms of peripheral neuropathy depend upon which type of nerves are injured, for example:
Sensory nerves - Damage to sensory nerves can produce symptoms such as pain, numbness, tingling, burning, or a loss of sensation or feeling.
Motor nerves - Damage to motor nerves results in decreased movement or control of muscles.
Peripheral nerves that link to the autonomic nervous system affect involuntary body functions and damage can result in:
- cardiac symptoms such as heart rate irregularities and orthostatic hypotension (drop in blood pressure when standing up from a sitting position)
- impaired ability to regulate body temperature
- blurred vision
- reduced sweating
- dizziness
- bowel/bladder dysfunction
- sexual dysfunction
Peripheral neuropathy is often classified on the basis of the pattern and distribution of the symptoms. This classification system includes the following major groups:
Mononeuropathy - characterized by involvement of a single peripheral nerve. This is most likely to be the result of trauma or nerve entrapment such as carpal tunnel syndrome, which is the most common cause of mononeuropathy.
Mononeuropathy multiplex - two or more peripheral nerves in separate parts of the body are affected. The pattern of involvement is random, may appear in many places, and typically evolves quickly.
Polyneuropathy - affects multiple nerves, may affect more than one extremity, and often occurs on both sides of the body (symmetric). The most common type of polyneuropathy is distal symmetric polyneuropathy. It involves long sensory nerves and symptoms usually appear first in the toes and the soles of the feet. Early symptoms include numbness, tingling, paresthesia, and burning.
Diabetes mellitus (type 1 and type 2) is the most common cause of peripheral neuropathy in Western countries and accounts for more diabetes-related hospitalizations than any other complication. Although the cause of diabetic neuropathy is not completely understood, it is thought that the metabolic consequences of insulin deficiency and hyperglycemia (higher than normal levels of sugar in the blood) are responsible for initiating damage to the nerve fibers.
Peripheral neuropathy is associated with several types of cancers and is thought to affect as many as 5% of cancer patients. Cancer-related neuropathies may be caused by the spread of cancer to the nervous system or compression of a tumor on a nerve. Most cases of cancer-related neuropathy, however, are caused not by the cancer itself, but by the neurotoxic effects of chemotherapy used to treat the cancer. While chemotherapy is designed to destroy cancer cells, it also damages or destroys other healthy cells in the body, including peripheral nerve cells. Overall, the incidence of chemotherapy-induced neuropathy is estimated to affect 30% to 40% of cancer patients.
The primary goals of treatment for peripheral neuropathy include:
- Establishing and treating the underlying cause (if known)
- Controlling the symptoms
- Maintaining overall function of the affected limbs
- Preserving quality of life
The prognosis for patients with peripheral neuropathy ranges from excellent, in those cases where the neuropathy resolves completely, to less promising in more severe cases where the pain and other symptoms do not respond to treatment and may persist for many years. Various medications, such as over-the-counter pain relievers, antidepressants, anticonvulsants, lidocaine patches, and others are available to relieve pain and symptoms of peripheral neuropathy, however, they are not effective for all patients. Peripheral neuropathy symptoms, particularly pain, numbness, and muscle weakness can have a significant negative impact on quality of life.
The Medifocus Guidebook on Peripheral Neuropathy is a unique, comprehensive patient education resource that contains vital information about Peripheral Neuropathy that you won't find anywhere else in a single resource. The Guidebook will answer many of your questions about this condition that your healthcare provider may not have the time to answer. To learn more about the Guidebook, please click here
