Recent advances in elucidating pain mechanisms.
OBJECTIVE
The purpose of this review is to highlight the important recent advances in this fast developing field of pain mechanisms. It is now recognized that acute tissue and neural injuries can result in nociceptor sensitization (primary hyperalgesia) and spinal cord hyperexcitability or central sensitization that results in secondary hyperalgesia and allodynia.


RESULTS
New findings regarding peripheral and central sensitization are presented in this review. Newer ideas on pain modulation, pain states and pain syndromes, mechanisms of chronic pain, newer opioid and non opioid medications including newer N-methyl-D-asparate antagonists, cyclooxygenase-2 inhibitors and membrane stabilizing analgesics as well as pain control at the genetic level are discussed.


CONCLUSIONS
The research of the last decade has focused on the biochemical and structural plasticity of the nervous system following tissue and nerve injury. The mechanisms involved in the transition from acute to chronic pain are complex with the involvement of interacting receptor systems and intracellular ion flux, second messenger systems, new synaptic connections and apoptosis.
Vadivelu
Nalini
N
Department of Anesthesiology, Yale University School of Medicine, New Haven, Connecticut 06824, USA. nalini.vadivelu@yale.edu
Sinatra
Raymond
R