Basal Ganglia Shape Abnormalities in the Unaffected Siblings of Schizophrenia Patients

Abstract

Objective-Abnormalities of basal ganglia structure in schizophrenia have been attributed to the effects of antipsychotic drugs. Our aim was to test the hypothesis that abnormalities of basal ganglia structure are intrinsic features of schizophrenia, by assessing basal ganglia volume and shape in the unaffected siblings of schizophrenia subjects.Method-The study involved 25 pairs of schizophrenia subjects and their unaffected siblings and 40 pairs of healthy controls and their siblings. Large deformation, high-dimensional brain mapping was used to obtain surface representations of the caudate, putamen, and globus pallidus. Surfaces were derived from transformations of anatomical templates and shapes were analyzed using reduceddimensional measures of surface variability (i.e. principal components and canonical analysis). Canonical functions were derived using schizophrenia and control groups, and were then used to compare shapes in the sibling groups. To visualize shape differences, maps of the estimated surface displacement between groups were created.Results-In the caudate, putamen and globus pallidus, the degree of shape abnormality observed in the siblings of the schizophrenia subjects was intermediate between the schizophrenia subjects and the controls. In the schizophrenia subjects, significant correlations were observed between measures of caudate, putamen and globus pallidus structure and the selected measures of lifetime psychopathology.Conclusions-Attenuated abnormalities of basal ganglia structure are present in the unaffected siblings of schizophrenia subjects. This finding implies that basal ganglia structural abnormalities observed in subjects with schizophrenia are at least in part an intrinsic feature of the illness. KeywordsSchizophrenia; Siblings; Basal Ganglia; Caudate; Putamen; Globus Pallidus Corresponding Author: Daniel Mamah, M.D., M.P.E. Department of Psychiatry (Box 8134), Washington University School of Medicine, 660 S. Euclid, St. Louis, MO 63110, (314) 747-2160, Fax: (314) 747-2182, E-mail: mamahd@psychiatry.wustl.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Evidence from family, twin and adoption studies suggest that genetic factors play an important role in the pathogenesis of schizophrenia (1,2). Consistent with the involvement of genetic factors in schizophrenia, cognitive (3,4), neurologic (5,6) and neurobiological (7,8) abnormalities have been found in the unaffected relatives of schizophrenia subjects, generally in attenuated form. NIH Public AccessA number of lines of research suggest that basal ganglia abnormalities mi...

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