by Dr. Robert Bennett

The 10th World Congress on Pain was held in San Diego CA August 17 to 22, 2002. This is a triennial meeting organized by the International Association for the Study of Pain (IASP), the leading world body for pain researchers and clinicians. It was a truly massive and overwhelming meeting with 1788 presentations of one type or another. I do not have a precise number for the attendees, but my estimate is about 3500.

The first day was devoted to refresher courses. I took part in one of these courses devoted to rheumatic pain disorders, giving a one-hour talk on fibromyalgia (FM). The other two speakers were from the UK; Professor Michael Doherty spoke on osteoarthritis and Professor Bruce Kidd spoke on rheumatoid arthritis. I was gratified to learn that at least some UK rheumatologists are focusing their attention on pain mechanisms—but as in many countries this continues to be an uphill battle. There were many sessions devoted to the basic mechanisms underlying chronic pain states such as FM. Indeed, FM was frequently referred to in many of these presentations as being the classical example of a "central pain state".  By this is meant that peripheral tissue causes of pain cannot be readily identified in most FM patients and that most of the action is at the level of the spinal cord and above. The neurophysiological and biochemical basis of central sensitization is now being unraveled in minute detail.  Much of this work relates to neurochemicals and their interaction with specific receptors. This is the basis of the transmission of sensory impulses from one nerve cell to another. In order to make advances in this field one must devote a large chunk of a research career to just one very specialized topic. Needless to say, the arcane nature of this work makes it very difficult to understand unless one is an "insider". However, understanding the detailed mechanisms of neurochemical receptor interactions will be pivotal in the creation of designer drugs for treating chronic pain, while minimizing the unwanted side effects that plague many of the currently available medications.