Task-state And Resting-state FMRI Study Of Numbness Induced By Electrical Stimulation In Normal Subjects

Part one Task-state fMRI study of numbness induced by electrical stimulation in normal subjectsObjective To provid a paradigm for the brain mechanism of numbness,and a biological basis for further study of the brain mechanism of numbness in related diseases by using task state magnetic resonance(Task-state fMRI)to evaluate the activation of functional areas of the brain in normal human under the condition of electrical stimulation numbness.Materials and Methods 22 healthy subjectsl,including 11 male and 11 female were recruited,who were right-handed,aged 24-30 years,with an average of 26±1.8 years old.A numbness model was made,with stimulation above the right ankle,by using the Shenzhen Low Frequency Pulse Electrical Stimulator(CL-105)press(PRESS)mode during fMRI data were acquired.The electrical stimulations of low frequency and high frequency were used with block design in the test,and the subjects were asked to score the numbness of electrical stimulation of the low frequency and high frequency..The statistical parameter map software package SPM 12 software was used to analyze the fMRI data,and the activation maps of the brain region were obtained for the low frequency electrical stimulation and high frequency electrical stimulation,and with SPSS20.0 software,the activation differences of the region of interest were analyzed by using the independent sample t test between the low-frequency electrical stimulation and high-frequency electrical stimulation.Results 1.The paired sample t test was used to analyze score of the numbness and valence: the numbness score of low frequency electrical stimulation was 3.50±0.96,and the numbness score of high frequency electrical stimulation was 7.27±1.28.Thedifference was statistically significant(t=13.18,p=0.000).valence score of the low-frequency electrical stimulation was 7.13 ± 1.28,and that of the high-frequency electrical stimulation was 3.54 ± 1.40.The difference was statistically significant(t=10.77,p=0.000).There was a significantly negative correlation between numbness and valence score for high frequency electrical stimulation(r=-0.53,p=0.011).2.The brain areas of increasing activation of high frequency electrical stimulation numbness compared to lower frequency electrical stimulation numbness in Task-state fMRI involved: left insular operculum,left middle cingulate gyrus,left planum temporal,right parietal operculum,left postcentral gyrus,posterior to the right insular lobe,left thalamus(FWE,corrected,p<0.05)..There were no brain areas of decreasing activation.Conclusion 1.There are negative correlations between strength of numbness of electrical stimulation and negative emotion produce with increase of numbness.2.The task-state fMRI study suggested that the brain area related to electrical stimulation of numbness involved the posterior central cortex of primary sensation,and thalamus and insular lobe related to the relay station of sensory conduction,as well as temporal lobe related to evaluation of numbness.The activation of these brain regions increases with numbness increase.Part two Resting-State f MRI study of numbness induced by electrical stimulation in normal subjectsObjective Resting-state functional magnetic resonance(Resting-State f MRI,rs-f MRI)was used to detect changes in resting brain function,f ALFF values and brain connectivity were analyzed,and brain function network changes related to numbness were further explored.Materials and Methods Twenty-two healthy subjects were enrolled in the hospital.There were 11 males and 11 females,who were right-handed,aged 24-30 years,with an average of 26±1.8 years.The experimentation was divided into two phases.In the first phase,the resting-state f MRI was used to collect the data of the resting brain function without electrical stimulation,and with electrical stimulation producing numbness above the right ankle in the second phase by using the stimulator PRESS mode.The f ALFF values,brain function connection maps and properties of brain network were analyzed using CONN software and paired sample t test was performed.Results 1.Increasing brain area of f ALFF included:Left and right medial frontal cortex and anterior cingulate gyrus,right temporal pole,right middle temporal gyrus,left middle temporal gyrus and inferior temporal gyrus,right inferior temporal gyrus and suboccipital gyrus;attenuated brain areas were left and right anterior cuneate lobe and posterior cingulate gyrus,right cerebellum.(FDRcorrected,p<0.05).2.There are significant differences in the brain connectivity between two resting states.Connections are weakened,involving the left formerly Supplementary Motor Area to the right Central Opercular Cortex,the left Supracalcarine Cortex to the right thalamus.connection are weakened,involving the right Inferior Frontal Gyrus to Frontal Medial Cortex,the right Cuneal Gyrus to calcarine Cortex,the right Cuneal Gyrus to language Gyrus,the left Supracalcarine Cortex to the left Intracalcarine Cortex(FDRcorrected,p<0.05).3.Results of resting state brain network showed that the clustering coefficients of the small world of brain network were reduced in the prefrontal cortex of the default network,the right dorsal attention network,the salience network.The average path length was shortened in the right salience network and frontoparietal network.The global effect increased in the node of inferior parietal lobe of the default mode network and the right salience network and frontoparietal network.Local effects decreased in the anterior part(medial prefrontal cortex)of the default mode network,left language system,and right salience network.The betweenness central effect of the anterior(medial prefrontal cortex)of the default network was enhanced,and the betweenness central effect was weakened in sensory-motor network(FDRcorrected,p<0.05).Conclusion 1.The use of electrical stimulators is feasible for the establishment of persistent numbness in normal subjects.2.Rs-fMRI study suggest that there are function changes in various brain regions during persistent numbness of electrical stimulation,numbness strength is related to cingulate and temperal pole,whereas emotional valence is related to fusiform gyrus,inferior temporal gyrus and occipital lobe.3.It is found that the resting brain network changes in the persistent numbness.In the state of persistent numbness,the sensory network and language network are weakened and the default network and visual network are enhanced.The global effect of the occipital lobe is enhanced and the local effect of the frontal lobe is weakened.