A Memory-Network Approach For Modulating Cognitive Function Of Patients With Schizophrenia Via Repetitive Transcranial Magnetic Stimulation

Objectives:Associative memory deficits is one of the core cognitive impairments of patients with schizophrenia,which have significant impact on functional outcome.Hippocampus plays an important role in forming associative memory,and hippocampal dysfunction has consistently been found in patients with schizophrenia.Previous studies showed that repetitive transcranial magnetic stimulation(rTMS)could modulate hippocampal function through cortical-hippocampus circuits.Therefore,in this study,we aimed to investigate the modulation effect of rTMS on hippocampal function of patients with schizophrenia by targeting right dorsolateral prefrontal cortex(DLPFC)and left lateral parietal cortex(LPC)separately.Methods:18 patients with schizophrenia were included in this study to accept intermittent theta burst stimulation(iTBS)intervention.Patients were randomly allocated to 3 groups: right DLPFC stimulation group,left LPC treatment group and sham stimulation group.All patients were given a 4-week iTBS treatment.Psychotic symptoms and cognitive function(including associative memory performance)were assessed at baseline and right after(less than 24h)the treatment.ResultsPatients with schizophrenia had a more prominent impairment in associative memory of visual domain.In schizophrenia patients,iTBS on the right DLPFC may reduce associative memory impairments of visual domain;while stimulation on the left LPC may eliminate the deficits of both auditory and across domain associative memory.Moreover,the negative symptoms of schizophrenia patients was conversely associated with associative memory performance(r=-0.550,p=0.022).Conclusions:iTBS on right DLPFC and left LPC may normalized the associative memory deficits of patients withschizophrenia,indicating that iTBS may be a promising tool for investigating the function of cortical-hippocampal network.Moreover,negative symptoms and associative memory impairments may share a common pathological mechanism,and associative memory may be a potential target for treating negative symptoms of schizophrenia.