Neuropathic Pain

What makes pain "neuropathic"?

Most pain is nociceptive: healthy nerves report real tissue damage, such as a sprained ankle or arthritis. In neuropathic pain, the nerves are the problem. Damaged nerve fibers fire spontaneously, become over-excitable, and the spinal cord and brain amplify their signals (central sensitization). Pain can therefore occur with no injury at all, or from things that should not hurt.

Many conditions, such as back pain with sciatica or cancer pain, involve both types (mixed pain).

Symptoms

• burning, shooting, stabbing or electric-shock-like pain
• pins and needles, crawling or "ants under the skin" sensations
• allodynia: pain from things that normally do not hurt, like bedsheets, clothing or a light breeze
• hyperalgesia: stronger pain than expected from a mildly painful stimulus
• numbness or reduced feeling in the same area
• pain that is worse at night
• poor sleep, low mood and anxiety, which in turn worsen pain

For a symptom-first guide to what nerve pain feels like and its causes by body area, see nerve pain.

Causes

Peripheral (nerves outside the brain and spinal cord)

• Diabetic peripheral neuropathy: the most common cause. Burning feet, worse at night, in a "stocking" pattern.
• Postherpetic neuralgia: persistent pain after shingles, more common over age 60.
• Nerve root compression: sciatica from a herniated disc, or a trapped nerve in the neck.
• Trapped nerves: carpal tunnel syndrome, meralgia paresthetica.
• Trigeminal neuralgia: brief, severe electric shocks in the face.
• Chemotherapy and other drugs: platinum drugs, taxanes, vincristine, some HIV and TB medicines.
• Alcohol, vitamin B12 deficiency, HIV, kidney failure, hypothyroidism, and inherited neuropathies.
• Surgery and injury: pain after mastectomy, thoracotomy, hernia repair, or nerve injury.
• Phantom limb pain after amputation.

Central (brain and spinal cord)

• spinal cord injury
• multiple sclerosis
• stroke, especially in the thalamus (central post-stroke pain)
• Parkinson's disease

Complex regional pain syndrome

CRPS causes severe burning pain, swelling, color and temperature changes in a limb, usually after an injury or surgery. It has both neuropathic and inflammatory features.

How neuropathic pain is diagnosed

1. History: the words you use (burning, electric, pins and needles) and the pattern of pain are strong clues. Screening questionnaires such as DN4, LANSS and painDETECT help.
2. Examination: a doctor tests light touch, pinprick, temperature, vibration, reflexes and strength to map the affected area.
3. Blood tests: blood sugar and HbA1c, vitamin B12, kidney and liver function, thyroid, and sometimes protein electrophoresis or HIV tests.
4. Nerve conduction studies and electromyography (EMG): measure how well large nerve fibers work.
5. Skin biopsy: counts small nerve fibers in small fiber neuropathy, which nerve conduction tests can miss.
6. MRI: of the spine or brain when a root compression, MS or stroke is suspected.

Treatment

The aim is a meaningful reduction in pain (often 30% to 50%) and better sleep and function. Complete relief is uncommon, so expectations matter.

Treat the cause

Good blood sugar control, stopping alcohol, B12 replacement, adjusting chemotherapy, or relieving nerve compression can stop progression and sometimes improve pain.

First-line medicines

Guidelines from NICE and the international NeuPSIG group recommend starting with one of:

• Amitriptyline or nortriptyline (tricyclic antidepressants), taken at low doses in the evening
• Duloxetine (an SNRI antidepressant)
• Gabapentin or pregabalin (gabapentinoids)

These work on nerve signaling, not mood, and take 2 to 4 weeks to judge. Doses are increased gradually. Common side effects are drowsiness, dizziness, dry mouth and weight gain. Gabapentinoids can cause dependence and are dangerous with opioids because of breathing suppression.

For trigeminal neuralgia, carbamazepine is the first choice.

Topical treatments

• Lidocaine 5% plasters for localized pain, such as postherpetic neuralgia.
• High-strength capsaicin 8% patches, applied in clinic every few months, for localized peripheral pain.
• Over-the-counter low-strength capsaicin cream helps some people, used several times a day.

Other options

• Tramadol or other opioids: only short term or as rescue in selected cases, because of limited benefit and significant risks.
• Combination therapy: low doses of two first-line drugs when one is not enough.
• Interventional treatments: nerve blocks, epidural steroid injections for radicular pain, spinal cord stimulation for persistent radicular pain or painful diabetic neuropathy, and surgery for trigeminal neuralgia.
• Botulinum toxin injections in some localized neuropathic pain.

Standard painkillers such as acetaminophen (paracetamol) and NSAIDs have little effect on pure neuropathic pain.

Non-drug approaches

• Physical therapy and graded activity to keep moving without flare-ups
• Cognitive behavioral therapy and acceptance-based therapy to reduce pain's impact on life
• TENS (transcutaneous electrical nerve stimulation) for some people
• Sleep and mood care, since poor sleep and depression amplify pain
• Foot care if feeling is reduced

Outlook

Neuropathic pain often lasts months to years. Some causes improve, such as nerve compression treated early or pain after shingles, which fades in many people within a year. Others, like long-standing diabetic neuropathy, are lasting but can be made much more manageable.

Frequently asked questions

What does neuropathic pain feel like?

It is usually burning, shooting, stabbing or like electric shocks, often with tingling, pins and needles or numbness. Light touch from clothes or bedsheets may hurt. It is often worse at night and follows the path of a nerve or affects both feet or hands.

What is the difference between nociceptive and neuropathic pain?

Nociceptive pain comes from damaged tissue, such as a cut or arthritis, and is reported by healthy nerves. Neuropathic pain comes from the nerves or brain being damaged. It feels different, often burning or electric, and responds to different medicines.

What is the best medicine for neuropathic pain?

There is no single best medicine. First choices are amitriptyline, duloxetine, gabapentin or pregabalin, chosen based on other health conditions and side effects. Lidocaine plasters or capsaicin patches help localized pain. Carbamazepine is used for trigeminal neuralgia.

Why don't regular painkillers work for nerve pain?

Acetaminophen and anti-inflammatory drugs act mainly on inflammation and tissue pain signals. Neuropathic pain comes from abnormal firing within nerves and amplification in the spinal cord and brain. Drugs that calm nerve signaling, such as gabapentinoids and certain antidepressants, are more effective.

Can neuropathic pain go away?

Sometimes. Pain from a compressed nerve may resolve once pressure is relieved, and pain after shingles often fades within months. Pain from long-term nerve damage, such as diabetic neuropathy, usually persists but can be reduced substantially with treatment.