Increased anterior cingulate and temporal lobe activity during visuospatial working memory in children and adolescents with schizophrenia

Abstract

Objective: Similar to adults, children and adolescents with schizophrenia present with significant working memory (WkM) deficits. However, unlike adults, findings of abnormal activity in the prefrontal cortex in early-onset schizophrenia (EOS) are not consistently reported. Since WkM continues to develop through adolescence and into early adulthood, patterns of activation in adolescents may be different than those found in adults. The goal of this study was to evaluate the functional neurobiology of WkM in patients with EOS. Method: Participants included 22 patients with EOS (mean age 15 ± 2.8. years) and 24 controls (mean age 15.0 ± 3.0. years). Diagnoses were confirmed using the KIDDIE-SADS-PL. All subjects underwent a functional MRI paradigm involving a visuospatial working memory task with three separate loads. Results: The behavioral results demonstrated deficits in EOS patients at all three WkM loads. On functional imaging, EOS patients demonstrated increased activation in the anterior cingulate cortex (ACC), medial temporal lobe structures, the insula, and bilateral lateral temporal lobes. Conclusions: Patients with EOS demonstrate increased activity in limbic structures and regions involved in processing primary and secondary sensory information. In addition, EOS patients had load dependent decreased activity in the parietal lobe. Unlike studies in adults, we did not find that EOS patients had activation differences in the frontal cortical regions. One possibility is that abnormalities in PFC function are related to secondary downstream or developmental processes which are 'unmasked' during development. Finally, our findings support growing evidence that EOS patients have aberrations in the limbic and temporal lobe regions.