| Objective To observe the effects of repetitive transcranial magnetic stimulation(r TMS)on cognitive function and EEG coherence in patients with mild cognitive impairment(MCI)in the states of rest and cognitive task.Method Nineteen patients with MCI were involved.They were randomly divided into two groups: 8 for MCI treatment group,9 for MCI control group.Meanwhlie,9 healthy volunteers were selected as normal control group.MCI treatment group were administrated r TMS on left prefrontal area(1Hz,110% RMT,1800 pulses/day,5 days/week,6 weeks together).All participants were performed measurement of scales and electroencephalogram in the states of rest and cognitive load before and after treatment.Furthermore,the coherence value between brain regions was calculated.All results were compared statistically between the pre-and protreatment.Result 1.Before treatment,the total score of Mo CA and scores in subtests of attentiveness,the delayed memory and abstract thinking in patients with MCI were significantly lower than normal.After treatment,the total score and scores in subtests of attentiveness and the delayed memory in MCI treatment group were significantly higher than before,and the variation rate of score in subtest—delayed recall was the highest.2.Before treatment,normal group gained higher MQ value of CMS and subtests scores except for the image free recall and meaningless image recognition than MCI.After r TMS treatment,the MQ value improved obviously in MCI treatment group than before.The subtext scores of point-to memory and associative learning increased significantly from the previous in MCI treatment group.Among them,the variation rate of point-to memory was the highest.3.Before and after treatment,there was no significant difference of interhemispheric and intrahemispheric coherence between MCI and normal control in rest state.However in cognitive state,the frontal-parietal and temporal-parietal coherence of theta,alpha,and beta bands in patients with MCI was significantly lower than that in normal control group before treatment.After treatment,the frontal-parietal,temporal-parietal coherence of theta and alpha band in the MCI treatment group was significantly higher than MCI control group,but still lower than the normal.Before rtreatment,the three groups showed significantly higher coherence in the most of interhemispheric leads of the theta,alpha,and beta bands in cognitive state compare with rest state.But there were only increased parietal-occipital coherence of alpha band in the cognitive state compared to the rest state of in patients with MCI.However in normal control group,the coherence of most intrahemispheric leads were increased in cognitive task than rest.After treatment,except for interhemispheric leads,MCI treatment group showed higher coherence of some intrahemispheric leads during cognitive task compared with rest state.Nevertheless,MCI control group showed no significant change.In addition,MCI treatment group showed higher frontal-parietal and temporal-parietal coherence of theta band in left hemisphere and frontal-parietal coherence of the alpha band in bilateral hemispheres during the cognitive state than before.But the coherence in some intrahemispheric leads were reduced in MCI control group after treatment.Conclusions 1.EEG coherence can be used as objective index to evaluate the cortical contact function of MCI.2.Unlike in the rest state,the dysfunction of intrahemispheric cortical contact in cognitive state can be found in patients with MCI,and show aggravating with time.3.r TMS can improves working memory efficiency as well as attentiveness,delayed memory of MCI by means of enhencing functional connectivity among the intrahemispheric cortical regions.4.More slight damage of cortical connection and effect of r TMS can be detected with the help of EEG coherence analysis in cognitive state in patients with MCI.5.r TMS can be used as a safe and effective non-drug therapy for clinical application. |
PDF Full Text Request