Changes over time in frontotemporal activation during a working memory task in patients with schizophrenia

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Psychology

Background:

• Working memory (WM) dysfunction is a core deficit in schizophrenia, often linked to prefrontal cortex abnormalities.
• Previous longitudinal studies suggest treatment can alter prefrontal activation patterns in schizophrenia patients.

Purpose of the Study:

• To investigate cerebral function during verbal working memory (WM) performance in medicated schizophrenia patients with acute symptom exacerbation compared to healthy controls.
• To examine changes in brain activation after a multimodal treatment over 7-8 weeks.

Main Methods:

• Event-related functional magnetic resonance imaging (fMRI) was used with a parametric verbal WM task.
• Schizophrenia patients were scanned twice: upon hospital admission and after 7-8 weeks of treatment with atypical antipsychotics.
• Healthy subjects served as controls.

Main Results:

• No significant differences in lateral prefrontal cortex activation were found between patients and controls at baseline or after treatment.
• Healthy controls exhibited greater activation in parietal, striatal, and cerebellar regions.
• Schizophrenia patients demonstrated bilateral enhancement of frontotemporal activation after 7-8 weeks of treatment, correlating with improved WM accuracy, WM span, and reduced BPRS scores (global and thought disturbance factor).

Conclusions:

• While functional hypofrontality was not replicated, frontotemporal activation in schizophrenia patients changed significantly with multimodal treatment.
• Treatment-associated changes in frontotemporal activation were positively associated with improvements in verbal WM performance and reductions in psychopathology.