Neuropathic Pain
Nerve pain — causes, assessment and evidence-based management
Neuropathic pain arises from a lesion or disease affecting the somatosensory nervous system. It affects up to 8% of the UK population and is characterised by distinctive symptoms including burning, shooting, or stabbing pain, allodynia (pain from normally non-painful stimuli), and hyperalgesia. It often responds poorly to standard analgesics and requires specific pharmacological management guided by NICE CG173.
What is Neuropathic Pain?
Neuropathic pain is pain caused by abnormal processing of sensory signals as a result of injury or dysfunction of the nervous system. It differs fundamentally from nociceptive pain (caused by tissue damage) in its underlying mechanisms and pharmacological management. Peripheral sensitisation occurs when injured nociceptors develop reduced activation thresholds and spontaneous discharges. Central sensitisation involves amplification of pain signals in the spinal cord and brain. Characteristic features include: allodynia (pain from light touch or temperature), hyperalgesia (exaggerated response to painful stimuli), dysaesthesia (unpleasant abnormal sensations), spontaneous burning or shooting pain, and paroxysmal electric-shock-like pain. These symptoms often follow the distribution of the affected nerve.
Causes
Common causes of neuropathic pain include: diabetic peripheral neuropathy (DPN) — the most prevalent form in the UK, affecting up to 50% of people with diabetes; post-herpetic neuralgia (PHN) — persistent pain following shingles, particularly in elderly patients; trigeminal neuralgia — severe, paroxysmal facial pain in the distribution of cranial nerve V; post-surgical neuropathic pain — following procedures such as thoracotomy, mastectomy or groin surgery; chemotherapy-induced peripheral neuropathy; cervical or lumbar radiculopathy (sciatica); complex regional pain syndrome (CRPS); and painful HIV-associated neuropathy. Central neuropathic pain occurs after spinal cord injury, MS, or stroke. Identifying the cause guides both treatment and prognosis.
Assessment (NRS, DN4, LANSS)
Assessment begins with a detailed pain history — character, distribution, onset, severity, aggravating and relieving factors, and impact on function and sleep. Validated screening tools aid diagnosis: the DN4 (Douleur Neuropathique 4 questions) questionnaire scores sensory qualities of pain — a score of ≥4/10 suggests neuropathic pain; the LANSS (Leeds Assessment of Neuropathic Symptoms and Signs) combines sensory and clinical examination; the Pain DETECT questionnaire is useful in primary care. The Numeric Rating Scale (NRS 0-10) quantifies pain severity. Neurological examination assesses sensory loss, allodynia and hyperalgesia in the painful area. Investigations include nerve conduction studies (NCS), quantitative sensory testing (QST), and skin punch biopsy to assess intraepidermal nerve fibre density in peripheral neuropathy.
Non-pharmacological Approaches
Non-pharmacological management is an essential component of neuropathic pain treatment. A comprehensive evaluation of the patient's pain history, functional impact, and psychological wellbeing guides an individualised management plan. Physiotherapy — TENS (transcutaneous electrical nerve stimulation) may provide short-term pain relief; graded motor imagery and desensitisation techniques are useful for CRPS. Psychological approaches — cognitive behavioural therapy (CBT) and acceptance and commitment therapy (ACT) are evidence-based for chronic pain; address catastrophising, pain-related fear, and disability. Pain management programmes (PMPs) — multidisciplinary programmes combining physiotherapy, psychology, education and group support — are highly effective for improving function and quality of life. Acupuncture has limited evidence for neuropathic pain. Lifestyle factors including regular gentle exercise, sleep hygiene, and social engagement all contribute to pain modulation. Addressing comorbid depression and anxiety is particularly important, as these amplify pain perception.