A13 Chronic neuropathic pain (central sensitization)

Title

Chronic neuropathic pain arises from a peripheral nerve injury that generates ectopic activity in the damaged fibers, due to overexpression of voltage-gated Na+ channels (direct extension of E02). Repeated stimulation of nociceptive C fibers produces the wind-up phenomenon, a progressive potentiation of the neuronal response in the dorsal horn that, sustained over time, is consolidated into central sensitization through NMDA receptor-dependent plasticity (same w formalism used in E07 and in the excitotoxicity of A05/A09). This sensitization, together with a reduction in descending inhibition from supraspinal centers, increases the net gain of the dorsal horn, expands the peripheral receptive field (allodynia), and reduces the pain threshold (hyperalgesia), so that previously innocuous or mildly painful stimuli generate a disproportionate pain response.

ID:4295