Subcortical overactivation in untreated schizophrenic patients: a functional magnetic resonance image finger-tapping study.

Functional magnetic resonance imaging (fMRI) is a well established, non-invasive technique for mapping the working brain. Yet imaging of subcortical regions has proven to be difficult. We studied 40 subjects performing an unilateral self-paced finger-tapping task. Patients with schizophrenia according to DSM-IV treated with olanzapine (n =10) or haloperidol (n=10) were compared to healthy controls (n =10) and untreated patients (n=10). Brainvoyager software was used for data-analyzing. All subjects showed highly significant activation in the contralateral sensorimotor area, the supplementary motor area and the ipsilateral cerebellum. In every investigated subject contralateral subcortical regions were also significantly activated (P < 0.001). Activation in ipsilateral pallidum was significantly higher in untreated patients compared with the other groups indicating an increase in subcortical coactivation. In addition, significant correlations were revealed within groups. This study emphasizes the possibility of investigating subcortical brain activation in patients with schizophrenia. The results of the present study outline the importance of further fMRI studies to investigate interindividual activation differences under different conditions especially focusing on basal ganglia.