Neuropathic Pain

Neuropathic pain is a type of chronic pain caused by injuries or diseases affecting the central nervous system (brain and spinal cord) or the peripheral nervous system (1).

Neuropathy can affect nerves that detect sensations such as coldness or pain (sensory nerves) and those that control muscle movement (motor nerves). In some cases, it could affect internal organs, such as the blood vessels, heart, bladder, or intestines.

People with this painful condition may experience burning, shooting pain. The pain may occur randomly, or it may be constant. A loss of sensation or a general feeling of numbness is typical, too.

Understanding the types and causes of neuropathic pain can help you find better treatments and ways to prevent the pain from getting worse over time.

Peripheral neuropathy

Peripheral neuropathy is the most common type of neuropathy. It occurs when the nerve damage affects the nerves outside of the brain, and spinal cord – these nerves are part of the peripheral nervous system, which sends sensory information from the central nervous system. The peripheral nerves inform the body when, for instance, the hands are cold. Accordingly, peripheral neuropathy is a condition that affects the nerves of the extremities – usually affects the legs and feet, as well as the arms or hands. It might send pain signals when there’s nothing causing pain, or they might not send a pain signal even if something is harming you.

Polyneuropathy

Polyneuropathy accounts for the highest number of peripheral neuropathy cases (2). It occurs when multiple peripheral nerves in the body malfunction simultaneously.

One of the most common types of polyneuropathy is diabetic neuropathy, a condition that usually affects people with diabetes. Other causes of polyneuropathy include malnutrition (particularly vitamin B deficiency), exposure to certain toxins such as with alcohol abuse, and complications from diseases such as kidney failure or cancer.

Because people with chronic polyneuropathy may lose their ability to sense pain and temperature, they may burn themselves and develop open sores as a result of prolonged pressure or injury.

Mononeuropathy

Damage to a single peripheral nerve or group of peripheral nerve is termed mononeuropathy. Physical injury or trauma, such as from an accident, is the most common cause. This condition causes a loss of movement, sensation, or function in that part of the body.

Prolonged pressure on a nerve, caused by extended periods of being sedentary (such as sitting in a wheelchair or lying in bed), or continuous, repetitive motions, can also trigger mononeuropathy.

There are several types of mononeuropathy, which vary in symptoms, seriousness, and rarity. One of the most common types is carpal tunnel syndrome. Carpal tunnel syndrome results from pressure on the median nerve in the arm, resulting in symptoms such as numbness, muscle damage, and weakness in the hand and fingers. Other mononeuropathies include ulnar nerve palsy, radial nerve palsy, and peroneal nerve palsy.

Autonomic neuropathy

Autonomic neuropathy refers to neuropathy that affects the internal organs. It results from damage to the nerves of the involuntary nervous system, which controls the heart and circulation (including blood pressure), digestion, bowel and bladder function, sexual response, and perspiration. This nerve damage disrupts signal processing between the autonomic nervous and the brain.

Injured autonomic nerves can affect your:

  • Blood pressure
  • Heart rate
  • Perspiration patterns
  • Bowel movements
  • Bladder emptying
  • Digestion

Autonomic neuropathy is often associated with other medical conditions and diseases and certain medications.

Your symptoms may vary based on the cause of your neuropathy and the location of your nerve damage. Early symptoms of autonomic neuropathy include dizziness or faintness when rising or standing, and vomiting, or feeling nauseated when eating. You may also have disturbances in bowel movements, bladder control, or sexual functioning.

Proximal neuropathy

Proximal neuropathy, otherwise known as diabetic amyotrophy, is a rare form of neuropathy. It refers to damage that causes pain explicitly in the shoulders, thighs, hips, or buttocks.

Proximal neuropathy is usually seen in adults over 50 years old with reasonably well-controlled type 2 diabetes. It more commonly affects men.

Symptoms usually affect only one side of the body. You may experience sudden and severe pain and muscle weakness in your legs that may make it difficult to stand up without assistance. After the onset of symptoms, it usually gets worse before eventually begin to improve gradually. Fortunately, most people recover within a few years, even without treatment.

Cranial neuropathy

Cranial neuropathy occurs when the cranial nerves (nerves that exit from the brain directly) are damaged. Two common types of cranial neuropathy are auditory neuropathy and optic neuropathy.

Auditory neuropathy involves the nerve that carries messages from the inner ear to the brain, which is responsible for hearing.

Optic neuropathy refers to damage or disease of the optic nerve that transmits visual cues from the retina of the eye to the brain.

Focal neuropathy

Focal neuropathy is restricted to one specific nerve or nerve group or one area of the body. It causes weakness in the affected area. Symptoms appear suddenly and are usually very painful.

Symptoms of focal neuropathy include:

  • Pain, numbness, tingling in fingers
  • An inability to focus
  • Double vision
  • Aching behind the eyes
  • Bell’s palsy
  • Pain in isolated areas, such as the front of the thigh, lower back, pelvic region, chest, stomach, inside the foot, outside the lower leg, or weakness in the big toe

Most focal neuropathies dissipate in a few weeks or months and leave no permanent damage.

What causes neuropathy?

Neuropathy may be caused by diseases, injuries, infections, or surgeries.

Disease

Neuropathic pain can be a symptom or a complication of several diseases or conditions.

Diabetes

Uncontrolled diabetes is characterized by chronic high levels of glucose in the blood (blood sugar), which can eventually damage nerves. This condition is termed diabetic peripheral neuropathy. It usually develops slowly, sometimes over several decades.

Diabetic peripheral neuropathy initially appears in the feet and legs and may occur in the hands and arms later. Occasionally you may be unable to feel your feet as you walk. Other times, your hands or feet will burn or tingle. Or it may feel like you’re wearing a glove or sock when you’re not.

The danger is usually when you can’t feel the pain, and an ulcer develops on your foot. If the ulcer heals poorly or becomes infected, amputation may be necessary.

Alcoholic neuropathy

Chronic alcoholism can be toxic to the nerves. People who drink too much may start to feel pain and tingling in their limbs, a condition known as alcoholic neuropathy.

Symptoms of alcoholic neuropathy include:

  • Numbness
  • Tingling and burning
  • Prickly sensations
  • Muscle spasms and cramps
  • Muscle weakness and atrophy
  • Loss of muscle functioning
  • Movement disorders

Although alcoholic neuropathy is not life-threatening, it can decrease your quality of life. The nerve damage is usually permanent, and your symptoms are likely to worsen if you don’t stop drinking. This could lead to disability, chronic pain, and damage to your arms and legs. However, if caught early enough, you can minimize the damage from alcoholic neuropathy by avoiding alcohol altogether.

Genetic or inherited disorders

Hereditary neuropathies, also known as inherited neuropathies, are passed on genetically from parent to child. It is uncommon.

Examples of genetic disorders that can cause neuropathy include Charcot-Marie-Tooth disease and Friedreich’s ataxia.

Charcot-Marie-Tooth. Charcot-Marie-Tooth disease is characterized by weakness in the legs and, to a lesser degree, the arms. The symptoms usually appear in adolescence or early adulthood. It is caused by degeneration of the insulation that generally surrounds the nerves and helps them conduct the electrical impulses needed for them to trigger muscle movement. This damage is mostly in your arms and legs.

Symptoms of Charcot-Marie-Tooth include:

  • Smaller, weaker muscles in the legs, ankles, and feet
  • Loss of sensation and muscle contractions
  • Difficulty walking or running
  • Foot deformities (e.g., hammertoes and high arches)
  • Difficulty lifting your foot at the ankle (footdrop)
  • Awkward or higher than standard step (gait)
  • Frequent tripping or falling

Friedreich’s ataxia. Friedreich’s ataxia, also known as spinocerebellar degeneration, is a rare genetic disorder. It causes difficulty walking, a loss of sensation in the arms and legs, and impaired speech.

Autoimmune neuropathy

Autoimmune diseases that cause autoimmune neuropathy include rheumatoid arthritis, Sjogren’s syndrome, systemic lupus, chronic inflammatory demyelinating polyneuropathy, vasculitis, and Guillian-Barre syndrome.

Tumors

Tumors can develop on the nerves or press against adjacent nerves. Also, polyneuropathy can arise from some immune-related cancers. Sometimes, chemotherapy treatment can also damage the nerves, leading to pain.

Idiopathic

Idiopathic neuropathy is neuropathy from an unknown cause. For one-third of people with neuropathy, the cause cannot be identified.

Trauma or injury

Trauma or injuries that affect the back, leg, and hip can cause neuropathic pain. While the injury may heal, the damage to the nervous system may not. As a result, you may experience persistent pain for many years after the accident.

Infection

Infections are a common cause of neuropathic pain. Types of infections that can damage nerves include HIV/AIDS, Lyme disease, leprosy, shingles, Epstein-Barr virus, hepatitis, diphtheria, and syphilis.

Surgery or amputation

A phantom limb syndrome is a rare form of neuropathic pain that can occur when an arm or leg has been amputated. Despite the loss of that limb, your brain still thinks it’s receiving pain signals from the removed body part. What’s happening, however, is that the nerves near the amputation site are misfiring and sending faulty messages to your brain. In addition to arms or legs, phantom pain may also be felt in other body parts.

Symptoms

Neuropathy is associated with characteristic symptoms. The extent to which an individual is affected by a particular neuropathy varies.

Symptoms of peripheral neuropathy

Every nerve in the peripheral system has a specific function, so symptoms depend on the type of peripheral nerves affected. There are three types of peripheral nerves – motor nerves, sensory nerves, and autonomic nerves.

Symptoms of motor neuropathy

Damage to the motor nerves can impair your ability to control movements. Symptoms include:

  • Muscle weakness or atrophy
  • Loss of reflex
  • Loss of muscle mass
  • Cramping
  • Muscle spasms or uncontrolled twitching
  • Loss of dexterity

Symptoms of sensory neuropathy

Sensory nerves send messages from other body parts to the brain and trigger your senses. When you experience a cold sensation or touch something sharp, you are using your sensory nerves.

Symptoms of sensory neuropathy often begin in the feet with a gradual onset of numbness, tingling, or pain. The symptoms progress toward the center of the body over time. The arms or legs may be affected. You may also be unable to determine your joint position, which can result in clumsiness or falls. The desensitization on your foot also means that blisters and sores on the feet may develop rapidly without being noticed. Because there is a limited sensation of pain, these sores may become infected, and the infection may spread to the bone – in severe cases, amputation may be necessary.

Symptoms of autonomic neuropathy

Autonomic nerves control involuntary and semi-voluntary functions, including blood pressure, heart rate, bladder functions, and sweating. If your autonomic nerves are affected by peripheral neuropathy, you may experience symptoms including:

  • Nausea and vomiting
  • Abdominal bloating after meals
  • Inability to control bowel and bladder functions
  • Irregular heart rate
  • Difficulty swallowing
  • Heat intolerance or not being able to sweat
  • Changes in blood pressure, causing lightheadedness or dizziness
  • Impotence (erectile dysfunction) in men
  • Constipation or diarrhea
  • Blurred vision

Symptoms of proximal neuropathy

Proximal neuropathy is a rare type of nerve damage in your buttock, hip, or thigh. It typically affects one side of your body.

Symptoms include:

  • Weakness in your legs that makes it challenging to stand from a sitting position
  • Sudden and sometimes severe pain in your hip, buttock, or thigh
  • Muscle wasting
  • Loss of reflexes such as the knee-jerk reflex
  • Weight loss

After the onset of symptoms, they typically worsen before gradually improving over months or years. In many cases, the symptoms do not dissipate completely.

Symptoms of cranial neuropathy

The cranial nerves arise directly from your brain or brainstem. They tend to affect areas like the eyes and face.

Symptoms include:

  • Pain
  • A tingling sensation
  • Numbness
  • Skin that feels sensitive to the touch
  • Weak or paralyzed muscles, causing drooling or slurred speech
  • Vision changes

Symptoms of focal neuropathy

Focal neuropathies can cause symptoms such as:

  • Eye pain
  • Double vision
  • Severe pain in a particular area, such as the lower back or legs
  • Bell’s palsy – paralysis on one side of the face
  • Belly or chest pain that may be mistaken for another condition, such as appendicitis or heart attack

Diagnosis

Diagnosis depends on the clinical presentation of the symptoms of the patient with suspected neuropathy.

Medical history

Your doctor will require a thorough medical history to determine the cause and severity of neuropathy. They will check your symptoms, lifestyle, drinking habits, and family history of neurological diseases.

Neurological examination

A neurological examination is essential for diagnosis. Your doctor might check for your tendon reflexes, your muscle strength and tone, your ability to feel certain situations, and your posture and coordination.

Tests

Electromyography (EMG)

EMG measures the function of the nerves. For this test, a thin needle containing an electrode is inserted through the skin to measure the electrical activity of the muscle.

Nerve conduction velocity (NCV) test

A nerve conduction velocity (NCV) test measures the speed at which signals travel through the nerves. NCV is often done concurrently with the EMG. In the NCV test, electrode patches are placed on the skin over nerves at various locations. Each patch gives off electrical impulses, which stimulates the nerve. The electrical activity of the nerves is measured, and the speed of the electrical impulses between electrodes is calculated.

Nerve biopsy

A nerve biopsy may sometimes be recommended. It is the surgical removal of nerve tissue, usually a sensory nerve, to look for abnormalities.

Imaging tests

Imaging studies such as X-rays, CT scans, and MRI scans may be performed to look for sources of pressure on or damage to nerves.

Treatments

Unfortunately, neuropathic pain can be challenging to resolve, with only 40-60% of people achieving partial relief. A multipronged approach, however, can be very effective in easing your symptoms.

The first goal of treatment for neuropathic pain is to address the underlying cause, if appropriate. Then, your doctor will aim to provide symptomatic relief, help you maintain typical capabilities despite the pain, and improve your quality of life. If your neuropathic pain does not have an identifiable cause, your doctor might recommend watchful waiting to see if your symptoms improve.

Anticonvulsants

Anticonvulsants may sometimes be used to treat neuropathic pain. Examples include gabapentin (Neurontin, Gralise, Horizant) and pregabalin (Lyrica).

Antidepressants

Antidepressant medications such as tricyclic antidepressants and serotonin-norepinephrine reuptake inhibitors can be used to treat neuropathic pain as well as symptoms of depression or anxiety caused by chronic pain.

Botulinum toxin type A

Local intradermal injection of botulinum toxin (Botox) is helpful in chronic focal neuropathies.

Neuromodulators

In cases that are difficult to treat, doctors may use neuromodulation to manage the pain effectively. Once the neuromodulator device is in place, it can send electrical impulses into the brain, spinal cord, or nerves. The impulses may stop irregular signals and control symptoms.

Types of neuromodulators include:

  • Deep brain stimulation
  • Motor cortex stimulation
  • Spinal cord stimulators and implanted spinal pumps

NMDA antagonism

The N-methyl-D-aspartate (NMDA) receptor may play a significant role in neuropathic pain and the development of opioid tolerance. NMDA antagonists such as ketamine, memantine, and dextromethorphan can alleviate neuropathic pain and reverse opioid tolerance.

Opioids

Opioids are used only in cases of chronic neuropathic pain. It is not used as a first-line treatment for short term neuropathy.

Topical agents

In some forms of neuropathy, the topical application of local anesthetics such as lidocaine patches is reported to provide relief. Likewise, capsaicin cream may also provide modest improvements.

Nerve block

In some cases, your doctor can inject pain medications into the nerves that are causing the pain. These blocks are temporary, so they must be repeated to keep working.

Management of underlying conditions

If another condition, such as diabetes, is involved, better management of the underlying disorder may alleviate the pain. Effective management of the disease can also help prevent further nerve damage.

Alternative therapies

Various alternative therapies might help ease the signs and symptoms of neuropathy.

Transcutaneous electrical nerve stimulation (TENS)

TENS involves using a small battery-operated unite and electrodes to apply a gentle electric current at varying frequencies. Apply it for 30 minutes daily for about a month.

Plasma exchange and intravenous immune globulin

Plasma exchange and intravenous immune globulin help suppress immune activity, which might benefit people with some types of inflammatory conditions.

Physical therapy

If you have muscle weakness, physical therapy could help improve your range of motion. You may also benefit from hand or foot braces, a walker, or a cane.

Acupuncture

Acupuncture promotes the natural relief of neuropathy pain. This technique involves the insertion of needles into various points on your body to stimulate pressure points. It triggers the nervous system to release chemicals that can change the pain threshold. It also provides an energy balance to improve your emotional well-being.

You might need multiple sessions of acupuncture before you notice improvement. It is generally safe when performed by a certified practitioner using sterile needles.

Meditation

Meditation techniques can help you live through your pain. It can help to improve your coping skills, decrease your pain intensity, and lower stress. It gives you more control over your condition.

Lifestyle remedies

Lifestyle remedies may help relieve neuropathic pain.

Alpha-lipoic acid (ALA)

Alpha-lipoic acid (ALA) supplements have been shown to reduce the symptoms of peripheral neuropathy. However, more research is necessary (3).

Cayenne pepper

Cayenne pepper contains capsaicin, an ingredient that has been used in topical creams for its pain relief properties. It is thought to decrease the intensity of pain signals transmitted throughout the body. Although it may initially cause a burning sensation, continued use will gradually reduce neuropathy sensations.

Exercise

Regular exercise can help to combat pain and increase blood flow to your arms and legs. Being active can also reduce your blood sugar levels, which, in turn, can reduce or slow down nerve damage.

Essential oils

Some essential oils can help to increase blood circulation in the body. They also have pain-relieving and anti-inflammatory properties.

Peppermint

Peppermint essential oil can relax muscles, control muscle spasms, and act as a pain reliever (4). Research also showed that the topical application of peppermint oil could help to relieve neuralgia in people who are resistant to other standard therapies.

Roman chamomile

Roman chamomile may also help soothe painful muscles. It also has antioxidative properties that could reduce inflammation.

Lavender

Lavender is found to have a calming and relaxing effect. It also could help minimize convulsions and spasms.

A mixture of essential oils

You may find synergistic relief by mixing essential oils to create a more robust solution. In a 2010 study, researchers found that a topical blend of geranium, lavender, bergamot, tea tree, and eucalyptus oil decrease pain within 30 minutes.

How to use essential oils for neuropathy

You can apply essential oils topically for pain relief. Add one ounce of carrier oil, such as coconut to olive oil, to every 12 drops of essential oil. Massage it gently into the affected areas.

CBD oil

CBD oil is a well-documented pain reliever. It works by interacting with the endocannabinoid system in the body to bolster the anti-inflammatory response. As a result, it can relieve many types of pain, including neuropathic pain.

One of the main benefits of using CBD products in the treatment of neuropathic pain is that it reduces the dependence on pain medications, such as opioids.

When taking full-spectrum CBD oil for neuropathic pain, it’s best to take it sublingually, which means applying it under the tongue. This method works best due to bioavailability.

Start by taking low doses of CBD oil to see what impact it has on your symptoms. You can always scale up from there if you do not see the desired results, increasing your dosage until the pain subsides.

Well-Concluded

The outlook for neuropathic pain depends on its cause and severity. If an underlying medical condition can be effectively treated and no permanent damage has occurred, the prognosis can be excellent. 

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