About Peripheral Nerve Pain

What is Peripheral Nerve Pain?

Peripheral nerve pain, also known as peripheral neuropathy, is a condition resulting from damage to the peripheral nervous system — the vast communications network that transmits information between the central nervous system (the brain and spinal cord) and every other part of the body.

How Does Peripheral Nerve Pain Impact Your Health and Function?

The impact of peripheral nerve pain on health and function can be significant. Chronic pain can interfere with daily activities and overall quality of life. The numbness or lack of sensation can increase the risk of injury as affected individuals may not sense temperature changes or pain on the skin. Also, people with peripheral neuropathy can struggle with tasks requiring fine motor skills. If motor nerves are affected, it could lead to muscle weakness and falls. Furthermore, some people experience sleep disturbances and mood changes, such as depression or anxiety, due to chronic pain.

Who is Most at Risk for Peripheral Nerve Pain?

Peripheral neuropathy can affect people of all ages, but the risk increases significantly with age. Other risk factors include certain medical conditions like diabetes (most cases of peripheral neuropathy are due to this), autoimmune diseases, infections, inherited disorders, and exposure to toxins. Lifestyle factors like alcoholism, poor nutrition, and vitamin deficiencies can also increase the risk.

Peripheral neuropathy can sometimes be a side effect of certain medications, especially those used to treat cancer (chemotherapy-induced peripheral neuropathy). Also, people with physical trauma or repetitive injury can develop this condition, as these can damage peripheral nerves.

What are the Causes of Peripheral Nerve Pain?

Several factors can cause peripheral nerve pain:

• Diabetes: This is the most common cause. High blood sugar levels can damage nerves over time, particularly in the legs and feet.
• Autoimmune diseases: Conditions like lupus, rheumatoid arthritis, and Guillain-Barré syndrome can lead to peripheral neuropathy.
• Infections: Certain viral and bacterial infections such as Lyme disease, shingles, hepatitis C, HIV, and others can also cause this condition.
• Inherited disorders: Some genetic disorders, like Charcot-Marie-Tooth disease, can cause peripheral neuropathy.
• Vitamin deficiencies: Lack of certain vitamins, particularly B vitamins and vitamin E, can lead to nerve damage.
• Alcoholism: Chronic alcohol abuse is toxic to nerves and can cause nutritional deficiencies leading to neuropathy.
• Exposure to toxins: Heavy metals, chemicals, or certain medications, especially those used in chemotherapy, can cause peripheral nerve damage.
• Other medical conditions: Kidney disease, liver disease, connective tissue disorders, and an underactive thyroid (hypothyroidism) can also cause peripheral neuropathy.

What are the Symptoms of Peripheral Nerve Pain?

The symptoms of peripheral nerve pain can vary widely, depending on the specific nerves affected, but can include:

• Sensory symptoms: These can include numbness, tingling, or prickling sensations, sensitivity to touch, or more severe pain, such as burning, jabbing, freezing, or sharp pain.
• Motor symptoms: Damage to motor nerves can cause muscle weakness, loss of muscle mass, cramps, and muscle twitching. Severe cases can lead to lack of coordination and balance or even paralysis.
• Autonomic symptoms: If the autonomic nerves, which control body functions like heart rate, digestion, and blood pressure, are affected, symptoms can include heat intolerance, excessive sweating or lack of sweating, problems with bowel, bladder or digestive functions, or changes in blood pressure causing dizziness or lightheadedness.

Consult a neurosurgeon if you suspect you may be experiencing symptoms of peripheral neuropathy. The condition can sometimes be reversed if the underlying cause is identified and treated early.

What are the Types of Peripheral Nerve Pain?

Peripheral nerve pain is classified based on the type and number of nerves affected, the part of the nerve affected, and the process by which the damage occurred.

Here are some common types:

• Mononeuropathy: In this type, only one nerve is damaged. Examples include carpal tunnel syndrome, which affects the nerve that provides sensation to the hand, and Bell's palsy, which affects the facial nerve.
• Polyneuropathy: This is the most common type and affects multiple peripheral nerves. The nerves are usually affected symmetrically (i.e., both sides of the body). An example is diabetic neuropathy.
• Motor neuropathy: This type specifically affects nerves controlling muscle movement.
• Sensory neuropathy: This affects nerves responsible for sensation, such as temperature, pain, vibration or touch.
• Autonomic neuropathy: This involves damage to the nerves that control involuntary body functions, such as heart rate, blood pressure, digestion, and sweating.

How is Peripheral Nerve Pain Diagnosed? 

Diagnosing peripheral nerve pain or peripheral neuropathy often involves a series of steps:

• Medical history and physical exam: Your doctor will review your medical history, symptoms, exposure to toxins, use of alcohol or drugs, and family history of neurological disease and may perform a neurological exam to check muscle strength, tendon reflexes, and sensitivity to touch, vibration, temperature, and body position.
• Blood tests: These can detect vitamin deficiencies, diabetes, immune system abnormalities, kidney function issues, and other indications of conditions that can cause peripheral neuropathy.
• Imaging tests: CT or MRI scans might be used to check for herniated disks, tumours, or other abnormalities that could be causing the nerve pain.
• Nerve function tests: Electrodiagnostic procedures, including electromyography (EMG) and nerve conduction studies, can detect abnormalities in the electrical activity of your muscles and how quickly your nerves transmit signals, which can help diagnose certain types of peripheral neuropathy.
• Nerve biopsy involves removing a small portion of a peripheral nerve to look for abnormalities. However, this is less commonly performed because it's invasive.
• Skin biopsy: In some cases, a small piece of skin might be removed to look for a reduction in nerve endings.

How Can Peripheral Nerve Pain Be Treated?

The treatment for peripheral neuropathy depends on the underlying cause. If the neuropathy is due to a treatable condition, like diabetes or vitamin deficiencies, then managing that condition can often reduce or eliminate the symptoms. Treatments can include:

• Medications: Over-the-counter pain relievers, anti-seizure medications, antidepressants, topical treatments, and opioids for severe pain can all be used to manage the symptoms of peripheral neuropathy.
• Therapies: Physical therapy can help to improve mobility, strength, and function. Occupational therapy can help with activities of daily living and improve safety. A TENS (transcutaneous electrical nerve stimulation) unit might relieve pain.
• Lifestyle changes: Healthy habits include regular exercise, maintaining a healthy weight, and avoiding factors that may cause nerve damage, including repetitive motion, cramped positions, smoking, and excessive alcohol use.
• Alternative medicine: Acupuncture, biofeedback, and relaxation techniques can also help manage pain.
• Surgery: In some cases, surgery might be an appropriate treatment option. Surgical interventions are often used for mononeuropathy cases, where a single nerve or group of nerves is impacted by compression or entrapment.

What if Peripheral Nerve Pain is Untreated?

If left untreated, peripheral neuropathy can lead to more serious health problems, including chronic pain, permanent nerve damage, foot ulcers, infections (which in severe cases could lead to amputation), falls and injuries due to loss of sensation and coordination, and in some cases, organ failure or even death if autonomic nerves are severely affected. Therefore, it's crucial to seek medical attention if you experience the symptoms of peripheral neuropathy.