Brain morphological and functional features in cognitive subgroups of schizophrenia

Abstract

Aim Previous studies have reported different brain morphologies in different cognitive subgroups of patients with schizophrenia. We aimed to examine the brain structures and functional connectivity in these cognitive subgroups of schizophrenia. Methods We compared brain structures among healthy controls and cognitively deteriorated and preserved subgroups of patients with schizophrenia according to the decline in IQ. Connectivity analyses between subcortical regions and other brain areas were performed using resting‐state functional magnetic resonance imaging among the groups. Results Whole brain and total cortical gray matter, right fusiform gyrus, left pars orbitalis gyrus, right pars triangularis, left superior temporal gyrus and left insula volumes, and bilateral cortical thickness were decreased in the deteriorated group compared to the control and preserved groups. Both schizophrenia subgroups had increased left lateral ventricle, right putamen and left pallidum, and decreased bilateral hippocampus, left precentral gyrus, right rostral middle frontal gyrus, and bilateral superior frontal gyrus volumes compared with controls. Hyperconnectivity between the thalamus and a broad range of brain regions was observed in the deteriorated group compared to connectivity in the control group, and this hyperconnectivity was less evident in the preserved group. We also found hyperconnectivity between the accumbens and the superior and middle frontal gyri in the preserved group compared with connectivity in the deteriorated group. Conclusion These findings provide evidence of prominent structural and functional brain abnormalities in deteriorated patients with schizophrenia, suggesting that cognitive subgroups in schizophrenia might be useful biotypes to elucidate brain pathophysiology for new diagnostic and treatment strategies.

Cognitive impairment in schizophrenia: relationships with cortical thickness in fronto-temporal regions, and dissociability from symptom severity

“…Abnormalities also link to the degree of cognitive impairment. A cognitively relatively intact subgroup of SZH seems to exist 24 with less pronounced cortical thinning 25 , 26 ; conversely, clustering patients according to cortical thickness patterns differentiate those with greater impairment 27 . The degree to which such neural correlates are attributable to cognitive impairment or to psychotic processes remains unclear, however.…”

Recent updates of eye movement abnormalities in patients with schizophrenia: A scoping review

“…Given that eye movement assessments are non‐invasive for patients, a promising future clinical research area is developing to evaluate potential relationships between disease characteristics and social functioning in patients with SZ 1, 2, 20, 61 . The growing number of reports aiming to understand the relationship between eye movement characteristics, intellectual functioning and differences in brain structures across patients with SZ provides valuable conclusions regarding cognitive impairments and social skills deficits, 221, 222, 224–230, 286 which in turn may be useful for therapeutics 17, 20, 182, 225, 228, 287, 288 …”

“…Overall, brain volume alterations, such as gray and white matter volume loss, enlarged ventricles, and change in the volume of the anterior cingulate cortex, insula and thalamus, have been identified in SZ patients 221, 224–226 . Notably, cognitive impairments that determine the quality of life and social functioning among patients with SZ have been reported to be related to brain structures 222, 226–230 .…”

“…Based on these findings, several independent research groups underlined the necessity to incorporate vision research into brain imaging studies; to investigate the relationship between eye movements, and structural and functional brain abnormalities in cognitive subgroups of SZ 225–227, 232, 233 . Furthermore, to show eye movement abnormalities among SZ patients and their relationship with patients’ social/intellectual functioning, 182, 234 researchers actively studied the association between eye movement abnormalities and (i) work hours (obtained through the Social Activity Assessment), 235 and (ii) the Wechsler Adult Intelligence Scale 44, 182, 230 .…”

Facilitative Effects of Transcranial Direct Current Stimulation on Semantic Memory Examined by Text-Mining Analysis in Patients With Schizophrenia

“…Healthy volunteers ( N = 335) were recruited from the community through local advertisements at Osaka University as participants in a general cognitive assessment ( 29 , 30 ). They were evaluated using the non-patient version of the Structured Clinical Interview for DSM-IV (SCID) to exclude individuals who had current or past contact with psychiatric services or had received psychiatric medication ( 31 , 32 ). Data was extracted from our previous study of the effect of tDCS on cognitive function in patients with schizophrenia ( 25 ), and from text-mining study using healthy adults ( 21 ).…”