Neuropathic pain

Neuropathic pain describes pain experienced as a consequence of a lesion or disease that affects the somatosensory nervous system. It is characterised by altered sensation (eg pins and needles, tingling), sensitisation (ie allodynia, hyperalgesia) and neuralgia.

Neuropathic pain is the dominant pain type in a number of painful conditions, including shingles and subsequent postherpetic neuralgia, diabetic neuropathy, chronic postsurgical or posttraumatic pain, complex regional pain syndrome and major burns. It is also experienced alongside nociceptive or nociplastic pain in several other painful conditions (eg chronic nonspecific low back pain, multiple sclerosis).

Assessment findings that suggest a neuropathic component to pain include:

• the description of pain as electric shocks, burning or ‘pins and needles’
• identification of allodynia or hyperalgesia on examination
• motor or sensory deficits in the painful area
• consistency between the area in which the pain is experienced and the innervation area of the affected neural structure.

Screening tools (eg PainDETECT) can help to identify pain likely to have a neuropathic component. Although imaging (eg magnetic resonance imaging [MRI]) can sometimes identify the cause of neuropathic pain, it should only be undertaken if it will change management—imaging should not be undertaken for the sole purpose of confirming the diagnosis.

When managing neuropathic pain, consider the general principles of acute or chronic pain management. The approach to managing acute neuropathic pain is described in more detail here.

Social, psychological and physical management techniques should be considered for all patients.

Analgesics are usually only partially effective for neuropathic pain; adjuvants are the mainstay of drug therapy. Drug therapy should not be used in children without specialist advice. For drug regimens for adults with neuropathic pain, see:

• Drug regimens for adults with acute neuropathic pain managed in the community
• Drug regimens for adults with acute neuropathic pain managed in hospital
• The role of analgesics in chronic noncancer pain.

With the exception of trigeminal neuralgia and radicular pain due to nerve root compression, surgery is generally ineffective for neuropathic pain and, in the medium to long term, may be associated with a worsening of pain symptoms.

Procedures such as nerve blocks, radiofrequency ablation, intrathecal drug administration, and implantation of peripheral nerve, spinal cord or motor cortex stimulators, may be considered in carefully selected patients after specialist review; see Invasive procedures to manage chronic pain.