Which statement about CRPS pathophysiology is true?

• A. Sympathetic nervous system involvement is minimal
• B. Central sensitization with neuropeptide release maintains inflammation
• C. There is no central sensitization in CRPS
• D. Peripheral nerve regeneration is the primary driver

Answer: (B)

Central sensitization with neuropeptide release maintains inflammation is the best description because CRPS pain and swelling arise from sustained hyperexcitability of central pain pathways plus ongoing inflammatory signaling. When nociceptors are activated, they release peptides such as substance P and CGRP. These neuropeptides promote neurogenic inflammation, causing vasodilation, edema, and further nociceptor sensitization. This peripheral inflammatory signal feeds back into the central nervous system, amplifying dorsal horn neuron excitability and sustaining pain even after the initial injury has healed. While sympathetic involvement and peripheral changes can occur, they are not the primary driver; the combination of central sensitization and neuropeptide–mediated inflammation best explains the persistent, amplified pain and inflammatory symptoms in CRPS.