Brain Anatomy Yields Schizophrenia Clues
Bower, B., Science News
Brain anatomy yields schizophrenia clues
Subtle but significant changes in brain anatomy are common features of people with schizophrenia, researchers report in the March 22 NEW ENGLAND JOURNAL OF MEDICINE. They base their conclusion on brain scans of 15 sets of identical twins, each pair consisting of one twin with schizophrenia and one without.
The findings provide the best evidence yet that nongenetic abnormalities exert an important influence on the development of schizophrenia, says Daniel R. Weinberger of the National Institute of Mental Health (NIMH) in Bethesda, Md., who conducted the study with Richard L. Suddath and three other NIMH colleagues. One possibility is that brain cells for some reason do not migrate to their appropriate destinations during the fetal development of people who later develop schizophrenia, Weinberger says.
In 12 of the 15 twin pairs, the researchers could identify the one with schizophrenia just by looking at magnetic resonance imaging (MRI) scans of the brain. Magnetic resonance imaging is a technique for taking pictures of various structures in a living brain. Visual clues to schizophrenia consisted of cearly enlarged ventricles -- three fluid-filled spaces deep within the brain.
Mathematical analysis of the data showed that, compared with their healthy twins, 14 of the 15 schizophrenics had at least one enlarged ventricle and also displayed size reductions in the temporal lobes, the hippocampus and the volume of the left temporal lobe's gray matter. The widely dispersed brain abnormalities occur in areas considered crucial to regulating emotion and motivation.
A control group of seven healthy identical-twin pairs showed no size differences in the same brain structures.
Brain abnormalities were not more severe among the schizophrenics with a long history either of the disorder or of antipsychotic drug treatment, the scientists note. Thus, the changes appear linked directly to schizophrenia, they say. …