PainOnline.com

We have spoken before about the unclear differences between central pain and central sensitization, which may be induced experimentally.

Iannetti and the brain trust at Oxford, reported in Dec 5 Proc National Acad Sci. US edition have cleverly done functional MRI imaging on the effects of gabapentin in normals and in those with central sensitization. The results should make Pfizer frustrated, since they lost a half billion to the U.S. Attorney for claiming Neurontin is effective against neuropathic pain. The reason is that The particular part of the insular cortex which determines the “painfulness of pain” is called the operculum (see article elsewhere at this site where Dr. Francis Crick explains the operculum and the role of the insular cortex). Ianetti showed that one 1800 mg dose of gabapentin does have a measurable effect on the insular cortex as follows:

1)gabapentin reduced activations in the insular cortex in the opercular area of both sides of the brain, WHETHER OR NOT central sensitization was present.

2) gabapentin reduced activation in the brainstem ONLY if central sensitization was present

3) attempts to induce deactivation by stimulation were suppressed by gabapentin when central sensitization was present.

The authors concluded that gabapentin’s effects are GREATER when central sensitization is present.

Whatever is shown, Pfizer is not likely to get their money back. The courts have never been noted for their adeptness at grasping science. They have even been accused of having an anti-science bias, said to be due the resentment by judges of anyone who claims to know more than they do. We are not necessarily in agreement, as we have noted certain judges, like the famed Justice Traynor of the Calif Supreme Court, who was able to handle science with the best of them. Unfortunately, Traynor’s skills do not seem to be shared by many on the bench.