neurologic disorders
Complex Regional Pain Syndrome (CRPS)
Pathophysiology of CRPS
Pathophysiology is unclear, but peripheral nociceptor and central sensitization and release of neuropeptides (substance P,calcitoningene-related peptide) help maintain pain and inflammation. The sympathetic nervous system is more involved in CRPS than in other neuropathic pain syndromes. Central sympathetic activity is increased, and peripheral nociceptors are sensitized tonorepinephrine(a sympathetic neurotransmitter); these changes may lead to sweating abnormalities and poor blood flow due to vasoconstriction. Nonetheless, only some patients respond to sympathetic manipulation (ie, central or peripheral sympathetic blockade). 