Objective: To evaluate the effect of different paradigms of repetitive transcranial magnetic stimulation (rTMS) on the treatment of schizophrenia through assessing cognitive function and psychotic symptoms.
Methods: Eighty patients diagnosed with schizophrenia were randomly assigned to four groups, which were sham intervention group, theta burst stimulation (TBS) group, 10 Hz group and 20 Hz group. All the subjects were exposed to 5 daily treatments at 80% of motor threshold over the left dorsolateral prefrontal cortex with a total stimuli of 1 200 per day, while being maintained on their former antipsychotic treatment. Visual spatial working memory test and verbal fluency test were applied to evaluate the cognitive function, while Positive and Negative Symptom Scale (PANSS) was used to assess the psychotic symptoms.
Results: 20 Hz of rTMS could improve the visual spatial working memory of schizophrenia patients (t=-2.469,P=0.024). Only patients in TBS group showed significant improvement of verbal fluency test after rTMS treatment (t=-4.538,P=0.000). The negative symptoms were alleviated significantly both in TBS and 10 Hz groups (TBS: t=5.373,P=0.000; 10 Hz: t=2.272,P=0.036). General psychopathology symptoms were improved significantly both in 10 Hz and 20 Hz groups (10 Hz:t=2.725,P=0.014;20 Hz:t=3.632,P=0.002).
Conclusion: The effects of rTMS on the cognitive function and psychotic symptoms of schizophrenia vary according to the changes in stimulus parameters, suggesting that rTMS could provide a new way for the individual therapy of schizophrenia.