Mechanisms of neuropathic and nociplastic pain: peripheral and central sensitisation

At a glance

• The IASP now groups pain by mechanism into three types. Nociceptive pain comes from damage to non-neural tissue. Neuropathic pain needs a lesion or disease of the somatosensory nervous system. Nociplastic pain (term adopted 2017) arises from altered nociceptive processing with no tissue damage or nerve lesion to explain it.
• Patients often have more than one. Cancer pain from a vertebral metastasis compressing a root is nociceptive and neuropathic together.
• Sensitisation is the shared engine. Peripheral sensitisation lowers nociceptor thresholds at the site of injury. Central sensitisation amplifies signals in the dorsal horn and brain, so pain spreads beyond the injury and non-painful touch hurts.