The Characteristics And Significance Of Brain Function Alterations In Patients With Acute Basal Ganglia Infarct Based On Multi-dimensional And Multi-frequency Of RS-fMRI

Part ⅠThe Characteristics and Significance of Brain Function Alterations in Patients with Acute Basal Ganglia Infarct Based on Multi-Frequency Bands ReHo Analysis BACKGROUND AND OBJECTIVE The blood oxygen level-dependent(BOLD)imaging technique of resting state functional magnetic resonance imaging(RS-fMRI)has been widely used to explore brain functional changes in neurology and neurological science.Regional homogeneity(ReHo),a data-driven method,measures the similarity or synchronization of the time series of nearest neighboring voxels,and can detect intensity of regional spontaneous brain activity at the resting state.Previous ReHo low-frequency(0.01-0.1 Hz)analysis showed that there were certain changes in brain function in patients with acute cerebral infarction,and such changes were understood as the result of brain functional remodeling in patients.However,the changes of brain function in patients with cerebral infarction may be the result of integration in the low frequency band,that is,the remodeling of brain function in patients with cerebral infarction may occur in a specific frequency band.In order to verify the above hypothesis,this present study used ReHo analysis based on multi-frequency to analyze the characteristics and clinical significance of BOLD signal changes in patients with acute basal ganglia infarct(BGI).ReTHODS In present study,39 patients with acute BGI and 45 healthy controls underwent RS-fMRI from May 2019 to December 2020.Neurological function deficits were evaluated using Fugl-Meyer scale(FMA)score,National Institutes of Health Stroke(NIHSS)score,Barthel index(BI)score,and modified Rankin(mRS)score,Montreal cognitive assessment(MoCA),and at admission.Prisma3.0 T MRI scan from Siemens was used within 10 days of onset to obtain highresolution 3D-T1 data and RS-fMRI data.At 3 months after onset,patients were followed up face to face or by telephone for mRS score.Three different frequency bands were used(traditional frequency band:0.01-0.08 Hz;Slow-5:0.01-0.027Hz;Slow-4:0.027-0.073 Hz)and ReHo metrics were compared and analyzed between patients with BGI and healthy controls.Finally,the signal values of ReHo in different brain regions in the three frequency bands of patients with BGI were extracted for correlation analysis with FMA score,NIHSS score,BI score,MoCA score,mRS score,respectively.RESULTS(1)Demographic and general data: Compared to healthy control group,hypertension,diabetes,hyperlipidemia,smoking and alcohol consumption are significantly higher in patients with acute BGI(P<0.05);MoCA score is significantly lower than that of healthy control group(P<0.001).There is no statistical difference in age,gender,and education level(P > 0.05).(2)Comparison of RS-fMRI brain region differences: Compared with the healthy controls,the ReHo value in all frequency bands of bilateral cerebellar Crus2 brain region in patients with acute BGI are decreased(P<0.005),and bilateral caudate increased in the Slow-5 frequency band.(3)Correlation analysis of brain region differences and clinical indexes in patients with BGI: The ReHo value of the left caudate in the Slow-5 frequency band is significantly increased,which was negatively correlated with the poor prognosis of neurological function at 3 months.CONCLUSION In this study,RS-fMRI multi-frequency ReHo analysis is applied to show the changes of brain function in patients with acute BGI.The ReHo value in bilateral cerebellar Crus2 brain region showed signal reduction at all three frequency bands,while bilateral caudate are characterized by increased signal in Slow-5 frequency band.It is suggested that the extent of early brain functional remodeling in BGI patients involved a wide range of regions such as cerebellum.It is suggested that there are frequency-specific alterations in the early brain function remodeling in BGI patients.Part Ⅱ The Characteristics and Significance of Brain Function Alterations in Patients with Acute Basal Ganglia Infarct Based on Multi-Frequency Bands DC AnalysisBACKGROUND AND OBJECTIVE Degree centrality(DC)analysis is another method of resting state functional magnetic resonance imaging(RS-fMRI)analysis,and it is the most direct index to describe the importance of local brain networks.Previous studies demonstrated that local functional network connectivity in the resting state was represent another form of brain functional remodeling in patient with acute cerebral infarction.However,there has been no report on the research of local functional network connectivity in patients with acute cerebral infarction using DC analysis.The purpose of this study was to investigate the characteristics and clinical significance of local functional network connectivity changes in specific frequency band in patients with acute basal ganglia infarct(BGI)based on DC method.METHODS In the present study,39 patients with acute BGI and 45 healthy controls underwent RS-fMRI.Neurofunctional scores such as Fugl-Meyer scale(FMA)score,National Institutes of Health Stroke(NIHSS)score,Barthel index(BI)score,modified Rankin(mRS)score,and Montreal cognitive assessment(MoCA)were evaluated at admission.RS-fMRI data within 10 days of onset were obtained from Prisma 3.0T MRI scan from Siemens of Germany.Patients were followed up face to face or by telephone for mRS score at 3 months of onset.Three different frequency bands are used(traditional frequency band: 0.01-0.08 Hz;Slow-5:0.01-0.027 Hz;Slow-4:0.027-0.073 Hz)and DC metrics were compared and analyzed between patients with BGI and healthy controls.Finally, the signal values of DC in different brain regions in the three frequency bands of patients with BGI were extracted for correlation analysis with FMA score,NIHSS score,BI score,MoCA score,mRS score,respectively.RESULTS(1)Demographic and general data: Compared to healthy control group,hypertension,diabetes,hyperlipidemia,smoking and alcohol consumption are significantly higher in patients with acute BGI(P<0.05);MoCA score is significantly lower than that of healthy control group(P<0.001).There is no statistical difference in age,gender,and education level(P > 0.05).(2)Comparison of DC metric brain region differences: Compared with the healthy controls,the DC value of bilateral cerebellum Crus2 brain region in the three frequency bands in patients with acute BGI are decreased(P<0.005).The size of differential cluster detected in Slow-4 is larger than that detected in conventional frequency band and Slow-5 frequency band.(3)Correlation analysis between DC values and clinical scores in patients with BGI: There is no significant relationship between DC values of different brain regions and clinical scores in the conventional frequency band(0.01-0.08Hz),Slow-5(0.01-0.027Hz)and Slow-4(0.027-0.073Hz)(P > 0.05).CONCLUSION DC analysis based on multi-frequency band of brain function changes in patients with acute BGI is characterized by decreased functional network connectivity in bilateral cerebellum Crus2 brain region under three frequency bands.Combined with the gradual improvement of the patients neurological function,it is suggested that multi-frequency band DC can describe the characteristics of early brain functional remodeling in patients.Part Ⅲ The Characteristics and Significance of Brain Function Alterations in Patients with Acute Basal Ganglia Infarct Based on Multi-Frequency Bands ALFF,fALFF and PerAF AnalysisBACKGROUND AND OBJECTIVE Amplitude of low frequency fluctuation(ALFF)and fractional ALFF(fALFF)are the most commonly used indicators of resting state functional magnetic resonance imaging(RS-fMRI)to measure spontaneous neural activity in the brain,which is used to monitor spontaneous low-frequency oscillations in the brain,but the results are susceptible to bold oxygen level dependent(BOLD)signal strength.Percent amplitude of fluctuation(PerAF)is the percentage ofALFF-based BOLD signal fluctuations relative to the average BOLD signal strength for a given time series,which is more reliable for measuring low-frequency oscillations in the brain.Previous low-frequency oscillations(LFOs)analysis ofALFF and fALFF showed that there would be some changes in brain function in patients with cerebral infarction,which was considered to be the result of brain functional remodeling.However,the changes of brain function in patients with cerebral infarction were not only the result of the comprehensive performance in the low frequency range,but may have frequency band specificity.In addition,PerAF analysis has not been reported to study the characteristics of LFOs in patients with cerebral infarction.In order to verify the above hypothesis,this study compared and analyzed the characteristics and clinical significance ofALFF,fALFF and PerAF methods to explore the changes of brain spontaneous LFOs in specific frequency bands in patients with acute basal ganglia infarct(BGI).METHODS In present study,thirty-nine patients with acute BGI and forty-five healthy controls were examined by RS-fMRI from May 2019 to December 2020.Neurological function deficits were evaluated using the Fugl-Meyer scale(FMA)score,National Institutes of Health Stroke(NIHSS)score,Barthel index(BI)score,modified Rankin(mRS)score,and Montreal cognitive assessment(MoCA)scores at admission.At 3 months after onset,patients were followed up face to face or by telephone for mRS score.Three amplitude methods including ALFF,fALFF,and PerAF at traditional frequency band(0.01-0.08 Hz)and Slow-5(0.01-0.027 Hz)and Slow-4(0.027-0.073 Hz)were applied to evaluate the spontaneous brain activity between patients with acute BGI and healthy controls.The correlation was performed between LFOs and clinical metrics scores in patients with acute BGI.RESULTS Compared to healthy control group,hypertension,diabetes,hyperlipidemia,smoking and alcohol consumption were significantly higher in patients with acute BGI(P<0.05);MoCA score is significantly lower than that of healthy control group(P<0.001).There is no statistical difference in age,gender,and education level(P>0.05).Compared to healthy controls,patients with acute BGI showed increased fALFF in the right Cerebelum＿3 in the Slow-4,decreased fALFF in the bilateral Cerebelum＿Crus2,decreased ALFF in the right Cerebelum＿Crus2 and the right inferior parietal lobule and right Supra Marginal,and decreased PerAF in the right postcentral the right inferior parietal lobule in all frequency bands.No correlation is found between local abnormalities and clinical metrics scores in patients with acute BGI.CONCLUSION Multi-frequency bands analysis ofALFF,FALFF and PERAF showed the changes of low-frequency oscillations in several brain regions in patients with acute BGI,suggesting that the simultaneous use ofALFF,fALFF,PerAF three analytical methods may be more comprehensive description of the patients brain function remodeling state.