New Brain Scan May Diagnose Bipolar Disorder
Technique Tracks Chemical Changes in the Brain
Nov. 30, 2004 (Chicago) -- Researchers using a special type of imaging that tracks brain chemicals are able to produce a "chemical fingerprint of bipolar disorder," a development that may lead to earlier diagnosis and aid in treatment.
If the results of this initial study are confirmed in larger trials, the technique, called MR spectroscopy, could "be a valuable diagnostic tool [for bipolar disorder] in two to three years," Mayo Clinic radiologist John D. Port, MD, PhD, tells WebMD. Port presented results of his preliminary study at the annual meeting of the Radiological Society of North America.
Doctors have long known that patients with bipolar disorder have abnormal amounts of certain chemicals in the brain that cause changes in mood - fluctuations between depression, normal mood, and mania.
MR spectroscopy uses ordinary MRI technology that is modified to view the chemical properties of brain tissue and thus theoretically can detect the chemical changes associated with bipolar disorder as well as other mental illnesses.
In Port's study, MR spectroscopy was used to analyze various parts of the brain in 19 patients with bipolar disorder and 19 people without the condition. They looked at the parts of the brain believed to be involved in causing bipolar disorder as well as one "control" region that was not believed to be affected by the disease.
The scan analyzed the byproducts of five brain chemicals believed to be in abnormal quantities in bipolar disorder. A graphic representation of these region-by-region variations was produced. Those regional differences "are the patterns that serve as a chemical fingerprint [for bipolar disorder]," Port says.
The 19 patients with bipolar disorder were not receiving drugs used to treat the condition. "We wanted a picture of the bipolar brain in its natural state, before drugs could alter brain chemistry," he says.
When he compared the MR spectroscopy images from the patients with bipolar disorder to scans of the people without the condition, "there were definite patterns -- different patterns -- that emerged in the bipolar patients," he says.
"Differences were clearly visible [within the brain] based on [the] mood state [of the patient]," he says.
Patients with the most severe bipolar disorder had different patterns than patients with mild to moderate cases, suggesting that the severe bipolar disorder may require a different or more aggressive treatment.
The researchers also discovered that an area in the back of the brain called the parietal white matter, which previous research suggested was not affected by bipolar disorder, does experience chemical shifts similar to those seen in other brain regions.
Port says the next step in the research will be a study of patients undergoing medical treatment for bipolar disorder to determine if MR spectroscopy can detect changes in brain chemistry in response to medication.
Philip O. Alderson, MD, professor of radiology at the College of Physicians and Surgeons of Columbia University in New York, tells WebMD that Port's study results are likely to be welcomed by psychiatrists "since they are very eager for a measurement tool that can be used to aid diagnosis." Alderson was not involved in the study, but he led a news conference at the meeting where the results were discussed.
Oden Gonen, PhD, a professor of radiology at New York University School of Medicine in New York, tells WebMD the results are "quite timely. The next step, of course, will be to use this technology to determine if medication can undo the apparent imbalance in brain chemistry. I think this is very, very promising."