Peripheral neuropathy refers to the condition that results from damaged nerve tissue. Peripheral nerve damage interrupts the signals passing from the brain to the rest of the body. This can lead to an array of symptoms that range from tingling or numbness in a body part, to muscle weakness and pain.
Causes of peripheral neuropathy
Peripheral neuropathy happens when nerves get damaged or become distressed.
This can happen as a result of other diseases and conditions, including physical injury, diabetes, and autoimmune diseases.
Complications of peripheral neuropathy
Left untreated, peripheral neuropathy can lead to additional complications. Having numbness in a part of the body might mean you don’t notice an injury to that region. Loss of coordination and balance might lead to more falls.
Peripheral neuropathy and the peripheral nervous system
The peripheral nervous system
Your peripheral nervous system is a vast network of nerves that relay information from your brain and spinal cord to the rest of your body.
Different types of peripheral nerves control a different function:
- Motor nerves control movement.
- Sensory nerves transmit sensory information to the brain
- Autonomic nerves regulate automatic bodily functions.
Together, these nerves transmit the information our body needs to function day to day.
What is peripheral neuropathy?
Peripheral neuropathy refers to the condition resulting from damaged nerve tissue. Peripheral nerve damage interrupts the signals passing from the brain to the rest of the body, leading to a variety of unpleasant symptoms. The exact symptoms depend on the type and location of the damaged nerve.
There are more than 100 types of peripheral neuropathy, each with its own set of symptoms and prognosis. To help doctors classify them, they are often broken down into the following categories:
- Motor neuropathy. This is damage to the nerves that control muscles and movement in the body, such as moving your hands or lips.
- Sensory neuropathy. Sensory nerves control what you feel, such as pain, temperature or a light touch. Sensory neuropathy affects these groups of nerves.
- Autonomic neuropathy. Autonomic nerves control functions that you are not conscious of, such as breathing and heartbeat. Damage to these nerves can be serious.
Neuropathies are also classified based on how many nerves are affected:
- Mononeuropathy means only one nerve is damaged. Carpal tunnel syndrome is a common form of mononeuropathy.
- Multiple mononeuropathy means that multiple nerves in different locations are damaged.
- Polyneuropathy refers to damage to several nerves in the same location. If you have polyneuropathy, you may have a mix of 2 or 3 of these other types of neuropathies, such as sensory-motor neuropathy.
What are the symptoms of peripheral neuropathy?
Symptoms aren’t always the same
Symptoms of peripheral neuropathy vary based on the type and location of the affected nerve(s). Symptoms can range from tingling or numbness in a certain body part to more serious effects. Symptoms can include:
- Loss of coordination or dexterity.
- Loss of feeling in a specific body part.
- Muscle weakness.
- Muscle twitching.
- Numbness. This usually starts gradually in the hands or feet and moves towards the trunk.
- Pain in the limbs during activities that shouldn’t cause pain (like pain in your hands while holding something light).
- Paralysis (if motor nerves are severely affected).
- Sharp, stabbing, or throbbing pain. Peripheral neuropathy pain can be severe for some people.
- Tingling (“pins and needles”) in the hands or feet.
When your autonomic nerves are affected
If autonomic nerves are affected, you may experience:
- Diarrhea, constipation, or loss of bowel control (incontinence), or other digestive symptoms due to nerve damage to the intestinal tract.
- Dizziness, lightheadedness, or fainting, due to unstable blood pressure.
- Emotional disturbances.
- Heat or cold intolerance, which is usually related to an inability to sweat.
- Inability to feel pain in the affected area, which can put you at risk for other injuries.
- Life-threatening symptoms, such as difficulty breathing or irregular heartbeat.
- Loss of bladder control (incontinence).
- Sleep disruptions.
- Trouble eating or swallowing.
Diagnosing peripheral neuropathy
The symptoms and body parts affected by peripheral neuropathy are so varied that it can make a diagnosis difficult.
Your doctor will start by getting your medical history and performing a physical examination. This initial assessment will provide your doctor with clues about whether your symptoms are caused by nerve damage.
If your cotor suspects nerve damage, he or she will do some neurological tests to determine the location and extent of your nerve damage. These may include:
Blood tests. No blood test can definitively diagnose peripheral neuropathy. However, they can indicate if you have an underlying condition, like diabetes, liver or kidney disease, or an autoimmune disorder.
Electromyography (EMG) and nerve conduction studies. Nerve cells communicate information by firing off electrical impulses. In an EMG, your doctor inserts a small needle into a muscle and monitors the electrical activity. At the same time, your doctor may conduct a nerve conduction study. Electrodes are placed on your skin, and a small electrical current is passed through them, stimulating your nerve cells. Your doctor can measure how well the nerves are responding to the electrical activity, which in turn allows them to see the extent of nerve damage.
Imaging exams. These tests create detailed images of the inside of your body. Doctors may use them to understand where the nerve damage is occurring and investigate the cause (such as a tumor or a herniated disk). Common imaging procedures include:
- CT scan
- MRI scan
Nerve and skin biopsy. A biopsy involves removing a small sample of tissue and examining it under a microscope for signs of disease. Your doctor may take a nerve biopsy (usually of a sensory nerve) to look for abnormalities that may be causing symptoms. Your doctor may also do a skin biopsy to see whether there has been a reduction in nerve endings.
Neurological examination. This may involve testing your reflexes, muscle strength, coordination, and ability to feel different sensations. Additional tests check for your ability to feel vibrations, sweat, and sense temperature changes.
Spinal fluid tests. A small amount of spinal fluid may be removed and tested for abnormal proteins or white blood cells, which may indicate an autoimmune response is causing symptoms.
How is peripheral neuropathy treated?
The first step to treating any type of peripheral neuropathy is treating the underlying condition that causes it.
- For a patient with diabetes, for example, this means working to control blood sugar levels and work towards a healthy lifestyle.
- For people with liver or kidney disease, cancer, or other illnesses, this means finding a treatment that manages or cures those conditions.
- In some cases, like peripheral neuropathy caused by vitamin deficiency, early treatment can help reverse the effects of peripheral neuropathy.
Unfortunately, nerve damage from diabetes or other conditions cannot be reversed, but treatment can help prevent further damage. Be sure to talk to your doctor about your treatment outlook so that you can create a treatment plan that meets your needs.
In addition to treating the underlying health problems that cause peripheral neuropathy, your doctor may recommend certain treatments to ease peripheral neuropathy symptoms. Read more below.
Anti-seizure medications. Anti-seizure drugs were developed to treat epilepsy. However, they may also help relieve nerve pain.
Antidepressants. Some antidepressants, known as tricyclic antidepressants, are effective treatments for neuropathy pain. These drugs increase the brain’s ability to ignore incoming pain signals, meaning you don’t feel as much pain.
Pain medications. In some cases, over-the-counter pain relievers can help with mild peripheral neuropathy symptoms. Look for non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and naproxen. For more severe nerve pain, you need a prescription pain reliever. Be sure to talk to your doctor about your options and potential side effects of pain relievers.
Topical creams. For some forms of mononeuropathy, like that which results from shingles, topical creams may be effective. These creams usually contain an active ingredient like lidocaine or capsaicin. Lidocaine is used for managing localized pain. Capsaicin (which is derived from hot peppers) can offer relief from pain and itching because it desensitizes the skin’s nerve endings. However, capsaicin can also increase small fiber nerve damage.
Other medications. If nerve damage affects your autonomic nerves, your doctor may prescribe medications to regulate your heart rate or control your blood pressure.
If your motor nerves are damaged, you may benefit from physical aids.
- Foot or wrist braces can help reduce pain that happens during day-to-day activities.
- Splints can help position your wrist or other affected areas so that the nerve is no longer pinched.
- Orthopedic shoes or insoles can help you walk more steadily and prevent foot injuries.
Be sure to talk to your doctor about these options, and he or she may refer you to a physical or occupational therapist for more help.
Surgery is sometimes recommended when mononeuropathy is caused by nerve compression. These are usually cases where pressure is being placed on the nerve by another body part, such as a protruding disk or a tumor. Carpal tunnel syndrome, for example, is a mononeuropathy that is effectively treated by surgery.
Surgery is less often recommended for polyneuropathy. This is because polyneuropathy tends to be more diffuse and complicated than mononeuropathy.
A variety of therapies can be used to manage peripheral neuropathy symptoms. These include:
Transcutaneous electric nerve stimulation (TENS). In this procedure, electrodes are attached to the skin near the affected area. During a 30 minute session, a mild electrical current is passed through the electrodes into the skin and muscles. The goal is for the electrical current to disrupt pain signals from reaching the brain.
Physical therapy. Physical therapy is designed to help you regain strength and mobility in the area affected by peripheral neuropathy. Your physical therapist can help you learn how to move to accommodate the affected injury, improve your coordination, and manage pain. They can also help you use physical aids like braces and splints effectively.
Plasma exchange (plasmapheresis). This treatment is common for people with autoimmune diseases. It involves filtering antibodies and immune proteins from the blood to suppress the immune system. The goal is to stop the immune system from attacking and damaging the nerves.
Can peripheral neuropathy be prevented?
Healthy lifestyle choices minimize risk.
Not all cases of peripheral neuropathy can be prevented. However, lifestyle choices can play a role in lessening your risks.
Things to avoid
- Avoid or quit smoking, maintain a healthy weight and active lifestyle, and avoid excessive alcohol consumption.
- Avoid toxins and always wear protective equipment at work.
Things to do
- Eat a varied diet and talk to your doctor about taking supplements if you have any vitamin deficiencies.
- Finally, if you have a chronic health condition, like kidney disease or diabetes, work with your healthcare provider to keep the condition under control. This can help prevent or delay peripheral neuropathy.