Baseline brain perfusion in schizophrenia revisited: An arterial spin labelling study

Several studies have demonstrated the existence of changes in brain metabolism or perfusion in schizophrenic patients using PET or SPECT in the past. Recent advances in magnetic resonance techniques such as CASL (continous arterial spin labelling) offer superior spatial resolution and allow repeated monitoring of perfusion levels by avoiding ionizing radiation. The purpose of this study was to investigate the capacity of CASL techniques in detecting baseline brain perfusion changes in schizophrenia. A sample of 31 right-handed schizophrenic patients was matched to 62 controls in sex, age, and date of study. Resting state perfusion was measured while participants lay in the scanner with closed eyes for 8min. In patients, relatively increased baseline perfusion was detected in the posterior cingulate and prefrontal cortex (postcentral gyrus), and in the basal ganglia (effect sizes between 3.5 and 4.5ml/100gr/min). Changes were more marked in the striatum, i.e. caudate nucleus and putamen, while spared the pallidum and the capsula interna. No significant increases were found in the control group compared to the patients. Arterial spin labelling techniques offer sufficient resolution to identify anatomical structures involved in perfusion changes associated with medicated patients, and may be applied to monitor the evolution of perfusion patterns during different phases of the illness and over the course of treatment.