Using new MR technique, researchers can see changes in brain chemistry

By Claire Dietz
HS News & Community Relations

What can newer functional imaging techniques teach physicians about treating panic disorder and related conditions?

The series of scans reproduced at left illustrates the generalized increase in brain lactate associated with a lactate-induced panic response. The inset image shows the part of the brain that appears in all the scans.

Dr. Stephen Dager, UW professor of psychiatry and behavioral sciences and of radiology, has received $2 million grant from the National Institute of Mental Health for “Neuroimaging of Panic.” Over the next five years, Dager and his colleagues will use the grant funding to learn more about how different therapies affect panic disorder-related brain chemical abnormalities that can be seen with recently developed imaging techniques. Dager is also an adjunct professor of bioengineering.

Using a modified form of magnetic resonsance imaging known as “PEPSI,” for proton echo-planar spectroscopic imaging, the researchers are able to take rapid “snapshots” of human brain chemistry in action. The technique is able to simultaneously measure changes in brain metabolism or chemical status in multiple regions of the brain. PEPSI was developed at the UW in collaboration with Dr. Stefan Posse with the Institute for Medicine in Julich, Germany.

In studies published in 1999, Dager used PEPSI imaging to look at the way brain chemistry responds to caffeine or caffeine withdrawal, and at the regional brain chemical manifestations of panic attacks.

Now he is focusing the technique on people with panic disorder, a fairly common mental disorder that can be difficult to treat effectively. In addition, many people who are effectively treated for panic attacks will relapse after treatment and experience symptoms again.

Dager and his colleagues will compare the effects of medication and of cognitive-behavioral therapy on normalizing brain chemistry that can be measured from the PEPSI images. A secondary aim of the project is to find brain chemical markers that may predict which people will have relapses after treatment.

“It seems that in some people with panic disorder the brain is able to re-regulate itself better than in others,” Dager said. “We’d like to know why.”

Along with brain chemistry, Dager said, the studies will look at actual brain anatomic structures, especially in the hippocampus. Some studies have indicated that stress may shrink the hippocampus.

Dager noted that the new grant relates to several other ongoing imaging projects at the UW, including National Institutes of Health-funded studies of brain chemical abnormalities in bipolar disorder and work characterizing brain development in young children with autism.

The work will be carried out at the UW’s Diagnostic Imaging Sciences Center and the Center for Anxiety and Depression, based in the Department of Psychiatry and Behavioral Sciences. Dager’s colleagues on the project include Drs. David Dunner, Julia Heiman, Debra Cowley and John Carr of the Department of Psychiatry; Drs. Seth Friedman and Todd Richards of the Department of Radiology; Dr. Alan Artu of the Department of Anesthesiology; and Dr. Kirk Beach of the Department of Surgery.

For more information on the project, contact Marie Domsalla, program coordinator, at 616-6801.