A PET-Scan To Picture Pain

Today's post from sciencedaily.com (see link below) looks at the use of a PET-scan (a sort of image scanner) to track pain in the sodium channels and therefore be better able to pinpoint its exact source. This is especially useful for neuropathy patients where the pain may seem to be in one area but originates from damage in another. At the moment, doctors base their analysis on patients own accounts of where the pain is and how severe it is but these are almost always completely subjective and can lead to mistakes in treatment. This form of scanning may help confirm the patient's opinion and help better direct any treatment.

Picturing Pain Could Help Unlock Its Mysteries, Improve Treatments
This article is based on materials provided by American Chemical Society. Dec. 11, 2013

— Understanding the science behind pain, from a simple "ouch" to the chronic and excruciating, has been an elusive goal for centuries. But now, researchers are reporting a promising step toward studying pain in action. In a study published in the Journal of the American Chemical Society, scientists describe the development of a new technique, which they tested in rats, that could result in better ways to relieve pain and monitor healing.

Sandip Biswal, Frederick T. Chin, Justin Du Bois and colleagues note that current ways to diagnose pain basically involve asking the patient if something hurts. These subjective approaches are fraught with bias and can lead doctors in the wrong direction if a patient doesn't want to talk about the pain or can't communicate well. It can also be difficult to tell how well a treatment is really working. No existing method can measure pain intensity objectively or help physicians pinpoint the exact location of the pain. Past research has shown an association between pain and a certain kind of protein, called a sodium channel, that helps nerve cells transmit pain and other sensations to the brain. Certain forms of this channel are overproduced at the site of an injury, so the team set out to develop an imaging method to visualize high concentrations of this protein.

They turned to a small molecule called saxitoxin, produced naturally by certain types of microscopic marine creatures, and attached a signal to it so they could trace it by PET imaging. PET scanners are used in hospitals to diagnose diseases and injuries. When the researchers injected the molecule into rats, often a stand-in for humans in lab tests, they saw that the molecule accumulated where the rats had nerve damage. The rats didn't show signs of toxic side effects. The work is one of the first attempts to mark these sodium channels in a living animal, they say.
 
 http://www.sciencedaily.com/releases/2013/12/131211131721.htm