Spatial working memory in individuals at high risk for psychosis: Longitudinal fMRI study

• Published in: Schizophrenia research Vol. 123; no. 1; pp. 45 - 52
• Main Authors: Fusar-Poli, P, Broome, M.R, Matthiasson, P, Woolley, J.B, Johns, L.C, Tabraham, P, Bramon, E, Valmaggia, L, Williams, S.C, McGuire, P
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-10-2010; Elsevier
• Subjects: Adult; Adult and adolescent clinical studies; Analysis of Variance; ARMS; Biological and medical sciences; Brain - blood supply; Brain - pathology; Brain Mapping; Cognition; Cognition Disorders - etiology; Cognition Disorders - pathology; Female; fMRI; Humans; Image Processing, Computer-Assisted - methods; Longitudinal Studies; Magnetic Resonance Imaging - methods; Male; Medical sciences; Memory, Short-Term - physiology; Mental Status Schedule; Neuropsychological Tests; Other psychotic disorders; Oxygen - blood; Prodromal psychosis; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Psychoses; Psychotic Disorders - complications; Psychotic Disorders - pathology; Risk Factors; Working memory; Young Adult; fMRI; ARMS; Cognition; Working memory; Prodromal psychosis; Human; High risk; Central nervous system; Metabolism; Nuclear magnetic resonance imaging; Encephalon; Psychosis; Follow up study; Risk factor; Medical imagery; Prepsychotic state; Functional imaging; Spatial memory
• ISSN: 0920-9964; 1573-2509
• DOI: 10.1016/j.schres.2010.06.008

Abstract Background Neurocognitive impairments in executive and mnemonic domains are already evident in the pre-psychotic phases. The longitudinal dynamic course of the neurofunctional abnormalities underlying liability to psychosis and their relation to clinical outcomes is unknown. Methods In this study we used functional magnetic resonance imaging (fMRI) in a cohort of subjects at ultra high clinical risk for psychosis (with an “At Risk Mental State”, ARMS) and in healthy controls. Images were acquired at baseline and again after one year on a 1.5 Tesla Signa, while patients were performing a visuospatial working memory task. Psychopathological assessment of the prodromal symptoms was conducted at the same time points by using the CAARMS and the PANSS instruments. Results There were no significant differences between the ARMS and control groups with respect to age or IQ. Although both groups performed the PAL task with a high degree of accuracy, the ARMS showed an increased latency in answers during the most demanding level of the task. At baseline, such cognitive impairment was associated with reduced activation in the left precuneus, left superior parietal lobule, right middle temporal gyrus in the ARMS as compared to controls. In addition, the ARMS failed to activate parietal areas with increasing difficulty of the task. Between presentation and follow-up the overall clinical status of the ARMS sample improved, despite 2 out of the 15 subjects having developed a full-blown psychosis: the CAARMS (perceptual disorder and thought disorder subscales) and the PANNS general scores decreased, while the GAF score increased. Such clinical amelioration was associated with a longitudinal compensatory increase in occipitoparietal regions. Conclusions The prodromal phase of psychosis is associated with functional alterations in parietal and temporal networks subserving visuospatial working memory which are more evident under high cognitive loads. The clinical improvement at one year is associated with a compensatory increase in occipitoparietal regions.