Neuropathic Pain

Neuropathic pain is a symptom mechanism, not a single diagnosis: a lesion or disease in the somatosensory system produces abnormal pain signalling. The bedside pattern is often a mismatch between symptom intensity and visible tissue injury. Patients may describe burning, electric shocks, shooting pain, pins-and-needles, or pain from light touch; numbness or reduced sensation can occupy the same territory. A pain adjective alone does not prove neuropathic pain. Nociceptive pain from inflamed or injured tissue may coexist, as in a painful diabetic foot with distal neuropathy, so inspect the skin, perfusion, joints, and function rather than attributing every symptom to nerves. Distribution gives the first useful map. Distal symmetric symptoms suggest polyneuropathy; a dermatomal band after zoster suggests postherpetic neuralgia; pain following one named nerve suggests peripheral injury or entrapment; a spinal cord or brain lesion can produce central pain. New motor deficit, rapidly progressive weakness, saddle sensory change, or bowel or bladder dysfunction shifts priority toward urgent neurological assessment for compression or another structural cause. That map also guides medication safety. First-line pharmacotherapy is usually chosen from a TCA,...