Shared mechanisms between chronic pain and neurodegenerative disease

Accumulating evidence indicates that chronic pain provokes morphological changes in the central nervous system. Animal models of neuropathic pain have revealed that degeneration of inhibitory interneurons in the dorsal horn of the spinal cord contributes to persistent pain after peripheral nerve injury. Brain imaging in patients with chronic pain demonstrates a decrease in neocortical gray matter and in brain metabolites, a sign of reduced neuronal density. Shared disease mechanisms suggest that chronic pain should be considered a neurodegenerative disorder.