Understanding the Basics of Peripheral Neuropathy

Tate Roberts, BSN, RN

Our brain is the part of our body that calls the shots. Your brain moves your body through electrical signals. These signals travel through neurons. It is estimated that there are about 86 billion neurons in the human brain. There are also neurons throughout our body. Those that are not found in our brain or spinal cord make up our peripheral nervous system.

Peripheral neuropathy is the result of damaged neurons in the peripheral nervous system. This can come from toxins, infections, injuries, or health problems such as diabetes.

Those with peripheral neuropathy use words like stabbing or burning to describe the pain caused by this problem. Most of the time symptoms can improve. Especially if they are related to a treatable condition. Certain medications have been shown to help reduce pain caused by peripheral neuropathy.

Symptoms

Having damaged peripheral nerves can lead to many signs and symptoms, including:

Numbness
Tingling in the affected area
Burning, jabbing, throbbing, or sharp pain
Extreme sensitivity
Pain while doing activities that normally don't cause pain
Poor coordination/falling
Muscle weakness, cramps, and or wasting
Paralysis
Constipation or diarrhea
Loss of bowel control
Rapid heart rate

Symptoms will vary depending on what groups of nerves are affected. There are three groups. These are:

Autonomic: These nerves are responsible for the processes of the body that are not normally seen (breathing, digestion, heartbeat, etc.)
Motor: These are responsible for the movement of muscles ( such as walking, typing, lifting patients, etc.)
Sensory: These are responsible for sensing the environment (hot, cold, sharp, etc.)

Causes

The list of causes of peripheral neuropathy is long. It includes systemic autoimmune diseases, hormonal imbalances, kidney and liver disorders, nutritional or vitamin imbalances, alcoholism, toxins, cancers, benign tumors, chemotherapy, infections, etc.

We will go into the three most common causes.

The most common cause of acquired single-nerve injury is physical injury. Car accidents, sports injuries, and falls can all damage peripheral nerves. Even less severe traumas can lead to peripheral neuropathy. Broken bones can put pressure on nearby neurons. Arthritis and other joint swellings can do the same. Prolonged application of casts and repetitive, forceful activities can cause ligaments and tendons to swell, narrowing nerve pathways.

The leading cause of polyneuropathy in the U.S. is diabetes. About 65% of people with diabetes have mild to severe forms of neural damage to all three nerve groups.

Vascular and blood issues can lead to peripheral nerves becoming hypoxic. This can lead to severe damage. Hypertension, atherosclerosis, smoking, and diabetes can impede blood flow. This results in patchy nerve damage also called multifocal mononeuropathy or mononeuropathy multiplex.

Diagnosis

A doctor will likely perform a physical exam and ask questions about medical history. Other tests can be performed, including:

Nerve Conduction Study: Electrodes are placed on the skin. Electricity is sent through the neurons to test how effective signals are transmitting.
Electromyography: This shows how well the body's signals move to the muscles. A small needle is placed into a muscle. The doctor then asks the patient to move the muscle. The probes within the needle measure the amount of electricity that is moving throughout the muscle.

Risk Factors

The risk factors for peripheral neuropathy include:

Autoimmune disease (lupus, rheumatoid arthritis, etc.)
Alcohol misuse
Diabetes
Exposure to toxins
Family history of neuropathy
Infections
Kidney disorders
Liver disorders
Repetitive motion
Thyroid disorders

Treatment

Treatments vary and depend on the type of nerve damage, symptoms, and location. Medicines are used, but some people can control their symptoms without them.

Many times, neuropathy will resolve itself if the underlying causes are corrected. Some common improvements in lifestyle habits that make a difference include:

Maintaining optimal weight
Eating a well-balanced diet
Reducing exposure to toxins
Correcting vitamin deficiencies
Smoking cessation
Exercise
Strict blood glucose monitoring
Use of immunosuppressive drugs such as prednisone, azathioprine, or cyclosporine.
Plasmapheresis
Use of other drugs such as some SSRIs, local anesthetics, anticonvulsants, and narcotics.
Surgery
Transcutaneous electrical nerve stimulation (TENS)

Prevention

The best treatment is prevention. Making healthy lifestyle choices can make all the difference later. Diets that include fruits and vegetables, whole grains, and lean protein are beneficial. Eating good foods protects against vitamin B-12 deficiency and other vitamin deficiencies. Regular exercise of at least 30 minutes a day promotes blood flow to different parts of the body.

Avoiding performing repetitive motions, putting pressure on nerves for long periods, exposure to toxins, drinking high amounts of alcohol, or smoking will greatly help to prevent peripheral neuropathy.

Any people have a disease that predisposes them to peripheral neuropathy. Getting it under control as best they can will help with prevention. The National Institute of Neurological Disorders and Stroke recommends that those over 50 get vaccinated against shingles and other diseases that are known to cause neuropathy.

Summary

Peripheral neuropathy occurs when the neurons outside the brain and spinal cord are damaged.

Symptoms vary greatly and depend on multiple factors. Pain, numbness/tingling, and irregular autonomic function are a few. The groups of neurons that can be affected are autonomic, motor, and sensory.

Peripheral neuropathy can be caused by many things. Three leading causes are physical injury, diabetes, and vascular/blood issues.

Diagnosis often involves nerve conduction study and electromyography.

Treatments differ from case to case and depend on the type of nerve damage, symptoms, and location. Much of the time, neuropathy will resolve itself if the underlying causes are fixed.

Prevention of peripheral neuropathy involves making healthy lifestyle choices, avoiding risk factors, and controlling existing diseases.

References

Peripheral neuropathy: Healthline

Peripheral Neuropathy: My Health Alberta

How Many Neurons Are in the Brain?: BrainFacts

Peripheral neuropathy: Mayo Clinic

Peripheral Neuropathy Fact Sheet: National Institutes of Health

Overview Peripheral neuropathy: United Kingdom National Health Service