Overview
Diagnose pain caused by a somatosensory lesion, identify urgent compressive and treatment-related causes, combine cause-directed care with a cautious adjuvant trial, and judge success by function and tolerability rather than complete symptom abolition.
Neuropathic pain is caused by a lesion or disease of the somatosensory nervous system. Descriptors such as burning, shooting, electric shocks, pins and needles, painful cold, allodynia and numbness raise probability but are not diagnostic alone. Symptoms should follow a neuroanatomically plausible peripheral nerve, root, plexus, stocking, hemibody or below-lesion distribution and be supported by sensory change on examination where possible.
Cancer-related neuropathic pain may result from direct invasion, spinal or foraminal compression, plexopathy, surgery, radiotherapy or chemotherapy. A new painful neuropathy is not automatically a late effect: rapid progression, motor loss, cranial neuropathy, sphincter change or asymmetry may indicate active tumour, inflammation or infection. Cause-directed imaging and specialist assessment can prevent irreversible disability.