The Strain in Pain Lies Mainly in the Brain

>Sean Mackey, M.D., Ph.D.
>
>The Strain in Pain Lies Mainly in the Brain:
>Applications of Engineering and Technology to Anesthesia and Pain Management
>
>
>Sean Mackey is Associate Director of the Pain Management Division at Stanford
>University, and Co-Director of the Stanford Pain and Research and Clinical Center
>at the Neuroscience Institute, also at Stanford University, as well as Assistant
>Professor at Stanford University in the Departments of Anesthesia and Neurosciences.
>
>Dr. Mackey has authored over thirty scientific papers, book chapters and review
>articles. His primary research interest involves the use of advanced imaging techniques,
>primarily functional magnetic resonance imaging (fMRI), to investigate the neural
>processing of pain and the factors that contribute to our perception of pain. He will
>describe ongoing research in helping patients experiencing chronic pain “see”
>their own brain activity in real time, and to use this information to control their brain
>activation in the region associated with the processing and perception of pain.
>
After a few jokes to wake us up, Dr. Mackey said that pain is the number one reason people see doctors. He quoted this definition "Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage." Forty to fifty million Americans are affected by pain every year. His center has studied it since the mid 1990s, working with volunteer patients and students mostly.

There are two kinds of nerve path that transmit pain signals from transducers throughout the body to the brain. A-fibers give you a quick jolt immediately after an experience, and C-fibers transmit that burning sensation that doesn't go away quickly. Dr. Mackey then went into some detail about which centers in the brain sense pain and how it is processed. One thing he mentioned was "If you decide not to pay attention to it, there are nerve fibers that tell your spine to "turn down that input.""

One of their big discoveries is that they are able to see the image of pain response in the brain on an MRI machine in real time. Apparently what happens is the brain saturates with blood in the area where pain is being experienced, so the image of it develops a "bright spot". They have used this feedback to learn a lot about how pain works. Several volunteers have been able to look at the feedback from their brains and turn down their response to pain, leading to more comfortable outcomes.

Dr. Mackey also said that many individual factors influence a persons feelings of pain. For example, they have learned that depression and pain are often connected, and that a patient experiencing both will probably need pain medication and counseling for either treatment to be effective. Cultural factors are also part of someone's experience of pain.

During Q&A the following came up:

Dr. Mackey believes that the placebo effect is real, and that it can be part of an effective pain management solution. He gave an example from his own experience, where patients consistently thought a cherry colored liquid did more pain management than pills with exactly the same medicine content.

Dr. Mackey has noticed that different generations have different vocabulary for discussing pain. For example, some of today's old Americans talk of "discomfort" when they mean pain.

Dr. Mackey has not been contacted by, and is not interested in dealing with the torture people from the U.S. Military.

Stanford's Pain Management Center does research with paid volunteers and patients who know what they are getting into. Dr. Mackey doesn't do experiments on animals.

At the Pain Management Center website are many links to articles, broadcasts, and other information from the center. For that, please visit:
http://paincenter.stanford.edu/