Peripheral neuropathy is a serious medical condition that can drastically alter an individual's life. There are over 100 types of peripheral neuropathy, and they can cause mild to severe symptoms. A subcategory of neurological disorders, peripheral neuropathy affects the brain, spinal cord, peripheral nerves, and extremities.
Definition & Facts
The peripheral nerves are those which originate in the brain and spinal cord and branch out into the organs, muscles, and skin. Peripheral neuropathy can be simply defined as a disease in which the peripheral nerves become damaged or diseased. It's estimated that over 20 million people in the United States suffer from some form of peripheral neuropathy.
Peripheral neuropathy can affect motor nerves, sensory nerves, and autonomic nerves. Motor nerves are those which control muscle movement. Sensory nerves receive sensory input from the environment and then relay information through the nervous system into the brain. Autonomic nerves control all of the internal organs of the body.
Symptoms & Complaints
Patients with sensory neuropathy commonly have nerve pain, burning and tingling sensations, and numbness of the hands and feet (parethesia). They also have decreased sensation in the extremities, which can lead to injury due to the inability to detect temperature and pain.
Sensory neuropathy is common among patients with diabetes and it can cause severe complications. For these patients, the inability of their bodies to properly heal after even the smallest amount of trauma can lead to infections and neuropathic arthropathy (Charcot joint) which causes the fracturing of the bones in the foot.
Autonomic nerve neuropathy symptoms are numerous and varied. Some common symptoms include increased blood pressure, loss of bladder control, excessive sweating, difficulty swallowing, difficulty breathing, and digestive problems.
The main cause of acquired damage to the peripheral nervous system is physical trauma. Car wrecks, falls, and other accidents can cause skeletal and nerve damage that ultimately leads to the development of peripheral neuropathy. However, the most common cause of peripheral neuropathy in the United States is diabetes due to diabetics’ chronically elevated blood glucose levels.
Vascular disease or disease of the blood vessels can cause peripheral neuropathy in a similar manner. The shrinking of the blood vessels that travel to the nerves can cause a decrease in the amount of oxygen and nutrients that are needed for proper nerve function. Alcohol abuse is also a common cause. Alcoholics and heavy users of alcohol for greater than 10 years are at an increased risk of developing the disease. Additional, less common causes are:
- Autoimmune diseases in which the body’s immune system attacks its own tissues and nerves
- Kidney diseases that cause an elevated amount of toxins in the blood which damage the nerves
- Viral infections and bacterial infections that attack the nerves (for example, herpes virus infection)
- Toxins from chemotherapy drugs.
- Environmental toxins such as lead, mercury, and arsenic
Finally, some cases are idiopathic (no cause).
Diagnosis & Tests
The first step in diagnosing peripheral neuropathy is recognition of the symptoms described above. Once symptom recognition occurs, patients are advised to see a medical doctor. The doctor will physically examine the patient and run tests before formally diagnosing the individual with peripheral neuropathy.
Examination of the patient involves obtaining a detailed medical history and performing a full neurological examination. Physical tests, blood tests, and electrodiagnostic tests all help the physician assess neurological function. Physical tests involve testing muscle reflexes and muscle strength. A common test is the knee jerk reaction test (patellar reflex test).
Blood tests are most often used to determine vitamin and toxin levels, but can be used to check for pre-existing medical conditions that put patients at an increased risk of developing peripheral neuropathy. Such conditions that may be tested for include endocrine diseases, HIV/AIDS, hepatitis B, and hepatitis C.
Electrodiagnostic tests measure the electrical activity of the muscles and nerves. Decreased electrical activity to a certain muscle group or area of the body can indicate that peripheral neuropathy is present. Electromyography (EMG) and nerve conduction velocity (NCV) tests are the two most common electrodiagnostic tests.
Treatment & Therapy
Treating the underlying cause of peripheral neuropathy is often times the most effective treatment. Effective treatment of trauma-related nerve injuries, diabetes, hypertension (high blood pressure), obesity, or alcoholism can lead to a decrease in the frequency and severity of peripheral neuropathy symptoms.
Adoption of a healthier lifestyle has also been shown to be an effective treatment method. Eating a healthy diet, engaging in regular exercise, and reducing stress can provide patients with reduction of symptoms.
One of the key factors in determining the success of treatment is how early in the disease's progress that it was detected. There are currently no treatment methods that reverse nerve damage. Thus, an early diagnosis can be tremendously beneficial because it allows treatment methods to slow down or stop the nerve damage.
Because patients experience a certain degree of nerve pain ranging from mild to severe, treatment focuses on reducing pain. Mild pain can be easily treated with over-the-counter nonsteroidal anti-inflammatory drugs; however, moderate to severe pain requires prescription medications. Narcotic painkillers are administered to patients whose pain cannot be controlled with other drugs.
Physical therapy can also be used to increase muscle strength and decrease muscle spasms and pain. A physical therapist can play a key role in a patient's treatment by analyzing a patient's movement and determining if a mobility aid such as a cane (assistive cane), walker, or wheelchair should be used.
Prevention & Prophylaxis