AUTHOR=Takayanagi Yoichiro , Kulason Sue , Sasabayashi Daiki , Takahashi Tsutomu , Katagiri Naoyuki , Sakuma Atsushi , Ohmuro Noriyuki , Katsura Masahiro , Nishiyama Shimako , Nakamura Mihoko , Kido Mikio , Furuichi Atsushi , Noguchi Kyo , Matsumoto Kazunori , Mizuno Masafumi , Ratnanather J. Tilak , Suzuki Michio 

TITLE=Structural MRI Study of the Planum Temporale in Individuals With an At-Risk Mental State Using Labeled Cortical Distance Mapping

JOURNAL=Frontiers in Psychiatry

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2020.593952

DOI=10.3389/fpsyt.2020.593952

ISSN=1664-0640

ABSTRACT=<p><bold>Background:</bold> Recent studies have demonstrated brain structural changes that predate or accompany the onset of frank psychosis, such as schizophrenia, among individuals with an at-risk mental state (ARMS). The planum temporale (PT) is a brain region involved in language processing. In schizophrenia patients, gray matter volume reduction and lack of normal asymmetry (left &gt; right) of PT have repeatedly been reported. Some studies showed progressive gray matter reduction of PT in first-episode schizophrenia patients, and in ARMS subjects during their development of psychosis.</p><p><bold>Methods:</bold> MRI scans (1.5 T field strength) were obtained from 73 ARMS subjects and 74 gender- and age-matched healthy controls at three sites (University of Toyama, Toho University and Tohoku University). Participants with ARMS were clinically monitored for at least 2 years to confirm whether they subsequently developed frank psychosis. Cortical thickness, gray matter volume, and surface area of PT were estimated using FreeSurfer-initiated labeled cortical distance mapping (FSLCDM). PT measures were compared among healthy controls, ARMS subjects who later developed overt psychosis (ARMS-P), and those who did not (ARMS-NP). In each statistical model, age, sex, intracranial volume, and scanning sites were treated as nuisance covariates.</p><p><bold>Results:</bold> Of 73 ARMS subjects, 18 developed overt psychosis (12 schizophrenia and 6 other psychoses) within the follow-up period. There were no significant group differences of PT measures. In addition, significant asymmetries of PT volume and surface area (left &gt; right) were found in all diagnostic groups. PT measures did not correlate with the neurocognitive performance of ARMS subjects.</p><p><bold>Discussion:</bold> Our results suggest that the previously-reported gray matter reduction and lack of normal anatomical asymmetry of PT in schizophrenia patients may not emerge during the prodromal stage of psychosis; taken together with previous longitudinal findings, such PT structural changes may occur just before or during the onset of psychosis.</p>