Background: Prefrontal cortical dysfunction is frequently reported in schizophrenia and is thought to underlie negative symptoms of schizophrenia. Repetitive Transcranial Magnetic Stimulation (rTMS) can modulate neuronal activity and has been shown to improve negative symptoms in patients with schizophrenia, but the underlying neural mechanism is unknown.
Objective: To examine whether 3weeks of 10Hz rTMS treatment of the bilateral dorsolateral prefrontal cortex (DLPFC) would improve frontal brain activation in patients with negative symptoms of schizophrenia, as measured by functional magnetic resonance imaging (fMRI) during the Tower of London (ToL) task.
Methods: 24 patients with the diagnosis of schizophrenia with moderate to severe negative symptoms (Positive and Negative Syndrome Scale (PANSS) negative subscale≥15) participated. Patients were randomized to a 3-week (15day) course of active or sham rTMS. All patients performed the ToL task during fMRI scanning both pre-treatment and post-treatment. Differences in brain activation between the two groups were compared non-parametrically.
Results: After rTMS treatment, brain activity in the active group increased in the right DLPFC and the right medial frontal gyrus as compared to the sham group. In addition, the groups significantly differed with regard to activation change in the left posterior cingulate, with decreased activation in the active and increased activation in the sham group.
Conclusions: Treatment with rTMS over the DLPFC may have the potential for increasing task-related activation in frontal areas in patients with schizophrenia. Effects of different rTMS parameters and fMRI tasks targeting relevant brain circuitry deserve further investigation.
Trial registration: Nederlands Trial Register, registration number: NTR1261.
Keywords: Functional; MRI; Prefrontal cortex; Repetitive; Schizophrenia; Tower of London; Transcranial Magnetic Stimulation.
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