Functional MRI study of mild Alzheimer＇s disease using amplitude of low frequency fluctuation analysis

Background Previous studies have shown that the functional brain activity in the resting state is impaired in Alzheimer＇s disease （AD） patients. However, most studies focused on the relationship between different brain areas, rather than the amplitude or strength of the regional brain activity. The purpose of this study was to explore the functional brain changes in AD patients by measuring the amplitude of the blood oxygenation level dependent （BOLD） functional MRI （fMRI） signals.

Modified constraint-induced movement therapy enhances cortical plasticity in a rat model of traumatic brain injury:a resting-state functional MRI study

Modified constraint-induced movement therapy(mCIMT)has shown beneficial effects on motor function improvement after brain injury,but the exact mechanism remains unclear.In this study,amplitude of low frequency fluctuation(ALFF)metrics measured by resting-state functional magnetic resonance imaging was obtained to investigate the efficacy and mechanism of mCIMT in a control co rtical impact(CCI)rat model simulating traumatic brain injury.At 3 days after control co rtical impact model establishment,we found that the mean ALFF(mALFF)signals were decreased in the left motor cortex,somatosensory co rtex,insula cortex and the right motor co rtex,and were increased in the right corpus callosum.After 3 weeks of an 8-hour daily mClMT treatment,the mALFF values were significantly increased in the bilateral hemispheres compared with those at 3 days postoperatively.The mALFF signal valu es of left corpus callosum,left somatosensory cortex,right medial prefro ntal cortex,right motor co rtex,left postero dorsal hippocampus,left motor cortex,right corpus callosum,and right somatosensory cortex were increased in the mCIMT group compared with the control cortical impact group.Finally,we identified brain regions with significantly decreased mALFF valu es at 3 days postoperatively.Pearson correlation coefficients with the right forelimb sliding score indicated that the improvement in motor function of the affected upper limb was associated with an increase in mALFF values in these brain regions.Our findings suggest that functional co rtical plasticity changes after brain injury,and that mCIMT is an effective method to improve affected upper limb motor function by promoting bilateral hemispheric co rtical remodeling.mALFF values correlate with behavio ral changes and can potentially be used as biomarkers to assess dynamic cortical plasticity after traumatic brain injury.

基于静息态功能磁共振低频振幅比率分析针刺与艾灸功能性消化不良患者足三里穴的脑功能响应差异

Objective:To explore the differences in the central response after acupuncture and moxibusbution at Zusanli(足三里ST36) in treatment of functional dyspepsia(FD) based on the analysis of fractional amplitude of low frequency fluctuation(fALFF) of resting-state functional magnetic resonance imaging(rfMRI).Methods:A total of 60 patients with FD were randomized into an acupuncture group and a moxibustion group,30 cases in each one.In the acupuncture group,acupuncture was applied to bilateral ST36.In the moxibustion group,moxibustion was exerted at bilateral ST36.The treatment was given once a day,5 times a week,totally for 4 weeks in each group,including 20 treatments with acupuncture or moxibustion.Separately,before and at the end of treatment,rfMRI scanning was conducted in two groups.Using data processing assistant for resting-state fMRI(DPARSF) software and MATLAB data platform,rfMRI data were collected for preprocessing and fALFF analysis.Results:Compared with the data before treatment,after treated with acupuncture at ST36 in FD patients,fALFF value was reduced in the right superior frontal gyrus,left superior frontal gyrus,left inferior frontal gyrus,right cuneus,left precuneus,right middle occipital gyrus,left middle occipital gyrus,etc.,and it was increased in the left parahippocampus,right parahippocampus,left cerebellum,etc(all P <0.01).After treated with moxibustion,the remarkable increase of fALFF was not discovered in brain areas,but fALFF decreased significantly in the left superior parietal gyrus(P <0.01).Compared with moxibustion at ST36,after acupuncture at ST36 in FD patients,the increase of fALFF appeared in the right putamen and the decrease of it occurred in the middle occipital gyrus,indicating the statistical significance(both P <0.05).Conclusion:The differences in central function responses are induced in treamtent with acupuncture and moxibustion,which is probably related to the resting-state default network associated with targeted regulation and ventral attention of brain areas in functional dyspepsia.

针刺治疗屈光参差性弱视:一项随机对照试验及其潜在起效机制

Objective:To evaluate the effect of acupuncture on anisometropic amblyopia(AA)and explore its potential mechanism for children with AA.Methods:Seventy-six children with monocular AA were randomized into a conventional treatment group and a combined treatment group of acupuncture and conventional treatment,with 38 patients in each group.In the conventional treatment group,on the base of patching regimen,the red flashing,grating and visual stimulation were delivered.Each approach lasted for 5 min per session and was given once every two days,three times a week,for 4 consecutive weeks.In the acupuncture-combined treatment group,on the base of the regimen of conventional treatment group,acupuncture was applied to Jingming(BL1),Cuanzhu(BL2),Fengchi(GB20)and Guangming(GB37),with needles retained for 20 min per session,once every two days,three times of intervention a week and for 4 consecutive weeks.Before and after treatment,the best corrected vision acuity(BCVA)was observed to evaluate the clinical effect in the two groups.Before treatment started,15 patients with AA on left side were randomized selected from each group and the resting-state functional magnetic resonance imaging(rs-fMRI)was operated before and after treatment.Simultaneously,eight healthy children with normal visual acuity were recruited to be the normal control group and received one-time rs-fMRI scanning.Based on the activation likelihood estimation(ALE),the visual"what"pathway network was constructed.By analyzing the amplitude of low frequency fluctuation(ALFF)and the regional homogeneity(ReHo),the differences in the regional autonomous function activities in the key brain areas of the"what"pathway were compared among the three groups.Results:(1)Clinical effect:After treatment,BCVA was(0.6[0.5,0.6]),higher than that(0.4[0.3,0.5])before treatment,presenting the statistical difference(P<0.05)in the conventional treatment group.BCVA was(0.6[0.6,0.8]),higher than that(0.4[0.4,0.5])before treatment,presenting the statistical difference(P<0.05)in the acupuncture-combined treatment group.BCVA in the acupuncture-combined treatment group was higher than that of the conventional treatment group(P<0.05)after treatment.The total effective rate was 86.1%in the acupuncture-combined treatment group,higher than that(65.8%)of the conventional treatment group(P<0.05).(2)Mechanism:(1)ALFF:In comparison with the healthy control group,the ALFF in the primary visual cortex of the"what"pathway for AA children was reduced significantly(P<0.05),and ALFF in the right fusiform gyrus and the right inferior temporal gyrus increased significantly when compared with the healthy children(P<0.05).Compared with that before treatment,there was no significant difference in the brain areas of the"what"pathway after treatment in the conventional treatment group(P>0.05).In the acupuncture-combined treatment group,ALFF in the right inferior occipital gyrus and the right fusiform gyrus of the"what"pathway increased after treatment when compared with that before treatment(P<0.05).After treatment,in comparison with the conventional treatment group,there was no significant difference in the brain areas of"what"pathway in the acupuncture-combined treatment group(P>0.05).(2)ReHo:ReHo in the right inferior occipital gyrus,the right fusiform gyrus and the right inferior temporal gyrus in the"what"pathway was elevated significantly in AA children when compared with that in the healthy control group(P<0.05).ReHo of the left inferior occipital gyrus and the left fusiform gyrus increased significantly after treatment when compared with that before treatment in the conventional treatment group(P<0.05).ReHo of the right inferior occipital gyrus,the left and the right fusiform gyrus increased significantly after treatment when compared with that before treatment in the acupuncture-combined treatment group(P<0.05).After treatment,ReHo of the right inferior temporal gyrus in the"what"pathway in the acupuncture-combined treatment group was significantly higher than that of the conventional treatment group(P<0.05).Conclusion:The acupuncture combined with conventional treatment improves BCVA and the total effective rate of AA children.The changes in the regional function activity of the brain areas within the"what"pathway were dominated by the compensatory increase of the autonomous activity in the occipital lobe(inferior occipital gyrus)and the temporal lobe(inferior temporal gyrus)in AA children.Both conventional treatment and acupuncture can enhance the intensity of autonomous function activities in the occipital lobe(inferior occipital gyrus)and the temporal lobe(fusiform gyrus/inferior temporal gyrus)in the"what"pathway so as to relieve visual impairment.ReHo in the inferior temporal gyrus in the acupuncture-combined treatment group was higher than that of the conventional treatment group and it suggests that the inferior temporal gyrus may be the key brain area to the improvement of visual function in the"what"pathway.