Lack of normal pattern of cerebral asymmetry in familial schizophrenic patients and their relatives - The Maudsley Family Study

Lack of the normal cerebral asymmetry has been reported in schizophrenia. W e wished to test the hypothesis that this lack of the normal pattern of asy mmetry is familial and that it can be found in both schizophrenic and nonsc hizophrenic family members. In particular, we wanted to know whether those relatives who appear to be transmitting liability to the illness also demon strate the loss of normal asymmetry. We studied families with several membe rs affected with schizophrenia. We carried out volumetric measurements of p refrontal, premotor, sensorimotor and occipitoparietal regions in each hemi sphere using 3D reconstructed MRI images in 29 schizophrenic patients, 55 o f their first degree relatives, and 39 unrelated control subjects on contig uous thin slices of the brain. Nine of the unaffected relatives appeared to be transmitting the liability for schizophrenia (e.g. the mother of a schi zophrenic patient who, although not psychotic herself, had a schizophrenic parent or sibling). We termed them presumed obligate carriers and the remai ning 46 relatives presumed non-obligate carriers. The healthy control subje cts showed larger right than left prefrontal regions and larger left than r ight sensorimotor and occipitoparietal regions. The schizophrenic patients showed lack of this normal brain asymmetry in the prefrontal, sensorimotor and occipitoparietal cortical regions. The presumed obligate carriers were similar to the schizophrenic patients in exhibiting lack of asymmetries in these cortical regions, while the presumed non-obligate relatives showed la ck of asymmetry only in the occipitoparietal region, There was no overall r eduction in total or regional brain volumes among the groups. Our findings indicate that lack of the normal pattern of frontal and occipital asymmetry is a marker for genetic liability to schizophrenia in families multiply af fected with schizophrenia. (C) 1999 Elsevier Science B.V. All rights reserv ed.