A Study of rTMS for Cognitive Deficits in Chronic Patients With Schizophrenia

A Randomized, Double-blind Study of Repetitive Transcranial Magnetic Stimulation for Cognitive Deficits in Chronic Patients With Schizophrenia in a Chinese Han Population

In this study, we assessed the therapeutic effects and safety of left dorsolateral prefrontal cortex (DLPFC) high-frequency repetitive transcranial magnetic stimulation (rTMS) on negative symptoms of schizophrenia. We evaluated the efficacy of rTMS on cognition in patients with chronic schizophrenia.

This is a randomized, sham-controlled, double-blinded trial. 47 patients diagnosed with schizophrenia on stable antipsychotic treatment were randomly assigned to active rTMS treatment group (n=25) or a sham rTMS treatment group (n=22). 25 patients in the active rTMS group received 10 Hz 110% rTMS, while 22 patients were subjected to sham rTMS, both being given 4-week treatment (5 days per week). Efficacy of negative symptom was assessed with the Scale for the Assessment of Negative Symptoms (SANS), the Positive and Negative symptom scale (PANSS) at baseline, the end of 4 weeks and 8 weeks. The cognitive function was assessed with CANTAB at baseline, the end of 4 weeks and 8 weeks .The side effects were assessed with Treatment Emergent Symptoms Scale at baseline and the end of 4 weeks.

Repetitive transcranial magnetic stimulation, Negative symptoms, randomized controlled trial, Schizophrenia, cognition

In this study, we assessed the therapeutic effects and safety of left dorsolateral prefrontal cortex (DLPFC) high-frequency repetitive transcranial magnetic stimulation (rTMS) on negative symptoms of schizophrenia. We evaluated the efficacy of rTMS on cognition in patients with chronic schizophrenia.

This was a single-institution, randomized controlled, double blinded trial. Participants were randomized to receive, over 4 weeks, 20 sessions of either active or sham rTMS. Clinical assessment was performed at baseline, 4 weeks and 8 weeks by 2 psychiatrists blinded to the treatment assigned. Inter-rater reliability was satisfactory (κa=0.86).

Prior to each TMS administration, motor threshold was determined by stimulating the left motor strip with the lowest possible energy to produce, within 10 stimuli, at least 5 evoked potentials Z0.05 . In active rTMS, 10 Hz stimulations over left DLPFC occurred at a power of 110% of MT for 5-s intervals with 30-s intertrain interval. 30 trains were administered each day (MondayFriday) for 4 consecutive weeks (total stimuli=30,000).

all procedures were identical except they were the unmagnetized steel cylinders, instead of cylindrical magnets, that were rotated. Participants were, therefore, unable to distinguish between active and sham rTMS.

Prior to each TMS administration, motor threshold was determined by stimulating the left motor strip with the lowest possible energy to produce, within 10 stimuli, at least 5 evoked potentials Z0.05 . In active rTMS, 10 Hz stimulations over left DLPFC occurred at a power of 110% of motor threshold (MT) for 5-s intervals with 30-s intertrain interval. 30 trains were administered each day (MondayFriday) for 4 consecutive weeks (total stimuli=30,000).

Inclusion Criteria: Right-handed; meeting the diagnosis of schizophrenia for at least 2 years; had been on anti-psychotic medications for more than 12 weeks; with unresolved negative symptoms (SANS>20). Exclusion Criteria: with substance use disorders ; with cerebral pathologies (e.g. seizure, aneurysm, stroke), intra-cranial metals, pacemakers, severe cardiovascular diseases; receiving electroconvulsive therapy in the past 3 months.