Understanding and Preventing Pain
My research program has 2 major objectives. The first is to assess the contribution of peripheral injury to the development of pathological pain states in which the central nervous system plays a prominent role.
The second is to design and systematically evaluate means of preventing the state of central neural sensitization that develops after injury and that often marks the transition from time-limited pain to chronic pathological pain.
Together, this research forms the basis of a model I have developed to evaluate the contribution of central nervous system plasticity to acute post-operative pain and hyperalgesia by altering the timing and route of administration of various analgesic agents relative to incision.
Surgery provides a context in which the central neural and primary/visceral afferent contributions of noxious intra-operative stimuli to subsequent pain can be studied in a controlled manner. We are conducting randomized, double-blind, placebo-controlled trials to evaluate a preventive approach to postoperative pain (called pre-emptive analgesia) that involves administering a variety of analgesic agents by different routes before incision. We are evaluating the effects of pre-emptive analgesia on intra-operative stress and immune status, post-operative pain, analgesic requirements and psychosocial functioning.
One series of studies assesses the mechanisms underlying the efficacy of pre-emptive analgesia by evaluating the role of specific agents that act at sites on the N-methyl-D-aspartic acid (NMDA) receptor (e.g., noncompetitive NMDA channel blockers such as ketamine and amantadine).
A second, related area of research is directed at understanding the mechanisms responsible the transition of acute pain to chronic, pathological pain.
I have approached this issue from 2 perspectives. One involves evaluating the role of pre-amputation pain in contributing to the central neuroplastic changes that underlie phantom limb pain 'memories'.
The second involves following up patients after other major surgical procedures in an attempt to identify early predictors of long-term pain.
Other research interests include gender differences in pain and analgesic use, phantom limb pain, and pain measurement.
- Professor and Canada Research Chair in Health Psychology, York University
- Professor, Department of Anesthesia, University of Toronto
- Scientist, Department of Anesthesia and Pain Management, Toronto General Hospital
- Scientist, Department of Anesthesia and Pain Management, Mount Sinai Hospital
- Associate Member, Department of Psychology, Hospital for Sick Children
- Adjunct Scientist, Toronto Rehabilitation Institute