Background. Repetitive transcranial magnetic stimulation (rTMS) of frontal brain regions is under study as a non-invasive method in the treatment of affective disorders. Recent publications provide increasing evidence that rTMS may be useful in treating schizophrenia. Results are most intriguing, demonstrating a reduction of negative symptoms following high-frequency rTMS. In this context, disentangling of negative and depressive symptoms is of the utmost importance when understanding specific rTMS effects on schizophrenic symptoms.
Method. Using a sham-controlled parallel design, 20 patients with schizophrenia were included in the study. Patients were treated with high-frequency 10 Hz rTMS over 10 days. Besides clinical ratings, ECD-SPECT (technetium-99 bicisate single photon emission computed tomography) imaging was performed before and after termination of rTMS treatment.
Results. High-frequency rTMS leads to a significant reduction of negative symptoms combined with a trend for non-significant improvement of depressive symptoms in the active stimulated group as compared with the sham stimulated group. Additionally, a trend for worsening of positive symptoms was observed in the actively treated schizophrenic patients. In both groups no changes in regional cerebral blood flow could be detected by ECD-SPECT.
Conclusions. Beneficial effects of high-frequency rTMS on negative and depressive symptoms were found, together with a trend for worsening positive symptoms in schizophrenic patients.