Altered spontaneous brain activity patterns in hypertensive retinopathy using fractional amplitude of low-frequency fluctuations:a functional magnetic resonance imaging study

AIM:To study functional brain abnormalities in patients with hypertensive retinopathy(HR)and to discuss the pathophysiological mechanisms of HR by fractional amplitude of low-frequency fluctuations(fALFFs)method.METHODS:Twenty HR patients and 20 healthy controls(HCs)were respectively recruited.The age,gender,and educational background characteristics of the two groups were similar.After functional magnetic resonance imaging(fMRI)scanning,the subjects’spontaneous brain activity was evaluated with the fALFF method.Receiver operating characteristic(ROC)curve analysis was used to classify the data.Further,we used Pearson’s correlation analysis to explore the relationship between fALFF values in specific brain regions and clinical behaviors in patients with HR.RESULTS:The brain areas of the HR group with lower fALFF values than HCs were the right orbital part of the middle frontal gyrus(RO-MFG)and right lingual gyrus.In contrast,the values of fALFFs in the left middle temporal gyrus(MTG),left superior temporal pole(STP),left middle frontal gyrus(MFG),left superior marginal gyrus(SMG),left superior parietal lobule(SPL),and right supplementary motor area(SMA)were higher in the HR group.The results of a t-test showed that the average values of fALFFs were statistically significantly different in the HR group and HC group(P<0.001).The fALFF values of the left middle frontal gyrus in HR patients were positively correlated with anxiety scores(r=0.9232;P<0.0001)and depression scores(r=0.9682;P<0.0001).CONCLUSION:fALFF values in multiple brain regions of HR patients are abnormal,suggesting that these brain regions in HR patients may be dysfunctional,which may help to reveal the pathophysiological mechanisms of HR.

Altered spontaneous brain activity patterns in patients with diabetic retinopathy using amplitude of low-frequency fluctuation

BACKGROUND Diabetes mellitus is a metabolic disorder characterized by prolonged elevation of blood glucose due to various causes.Currently,the relationship between diabetic retinopathy(DR)and altered connectivity of brain function is unclear.AIM To investigate the relationship between this brain activity and clinical manifestations and behaviors of DR patients by using the amplitude of low-frequency fluctuation(ALFF)technique.METHODS Twenty-four DR patients and 24 healthy controls(HCs)matched for age and gender were enrolled.We measured and recorded average ALFF values of DR patients and HCs and then classified them using receiver operating characteristic(ROC)curves.RESULTS ALFF values of both left and right posterior cerebellar lobe and right anterior cingulate gyrus were remarkably higher in the DR patients than in the HCs;however,DR patients had lower values in the bilateral calcarine area.ROC curve analysis of different brain regions demonstrated high accuracy in the area under the curve analysis.There was no significant relationship between mean ALFF values for different regions and clinical presentations in DR patients.Neuronal synchronization abnormalities in some brain regions of DR patients were associated with cognitive and visual disorders.CONCLUSION Abnormal spontaneous brain activity was observed in many areas of DR patients’brains,which may suggest a possible link between clinical manifestations and behaviors in DR patients.

Altered spontaneous brain activity patterns in patients with hyperthyroidism exophthalmos using amplitude of low-frequency fluctuation:a resting-state fMRI study

AIM:To assess changed spontaneous brain activity in hyperthyroid exophthalmos(HE)patients by the amplitude of the low-frequency fluctuation(ALFF)method,and to analyze the correlation between brain activity and ALFF values in these patients.METHODS:Totally 18 HE and 18 hyperthyroid nonexophthalmos(HNE)patients were enrolled.The participants were tested by resting-state functional magnetic resonance imaging,and receiver operating characteristic(ROC)curves were generated to classify the ALFF values of the study population.Pearson’s correlation analysis was utilized to evaluate the relationship between the ALFF values obtained from different brain areas and clinical manifestations.RESULTS:Contrary to HNE patients,we observed lower ALFF values in the left calcarine fissure and surrounding cortex(LCFSC)in HE patients.In the ROC curve analysis of the LCFSC,the area under the curve reflected a high degree of accuracy.In addition,there was positive correlation between mean ALFF values of the LCFSC and the bestcorrected visual acuity of the affected eyes.CONCLUSION:The study displays abnormal brain activity in LCFSC in patients with HE,which might suggest pathological mechanism of visual impairment of HE patients.

Changes in the amplitude of low-frequency fluctuations in specific frequency bands in major depressive disorder after electroconvulsive therapy

BACKGROUND Major depressive disorder(MDD)tends to have a high incidence and high suicide risk.Electroconvulsive therapy(ECT)is currently a relatively effective treatment for MDD.However,the mechanism of efficacy of ECT is still unclear.AIM To investigate the changes in the amplitude of low-frequency fluctuations in specific frequency bands in patients with MDD after ECT.METHODS Twenty-two MDD patients and fifteen healthy controls(HCs)were recruited to this study.MDD patients received 8 ECT sessions with bitemporal placement.Resting-state functional magnetic resonance imaging was adopted to examine regional cerebellar blood flow in both the MDD patients and HCs.The MDD patients were scanned twice(before the first ECT session and after the eighth ECT session)to acquire data.Then,the amplitude of low-frequency fluctuations(ALFF)was computed to characterize the intrinsic neural oscillations in different bands(typical frequency,slow-5,and slow-4 bands).RESULTS Compared to before ECT(pre-ECT),we found that MDD patients after the eighth ECT(post-ECT)session had a higher ALFF in the typical band in the right middle frontal gyrus,posterior cingulate,right supramarginal gyrus,left superior frontal gyrus,and left angular gyrus.There was a lower ALFF in the right superior temporal gyrus.Compared to pre-ECT values,the ALFF in the slow-5 band was significantly increased in the right limbic lobe,cerebellum posterior lobe,right middle orbitofrontal gyrus,and frontal lobe in post-ECT patients,whereas the ALFF in the slow-5 band in the left sublobar region,right angular gyrus,and right frontal lobe was lower.In contrast,significantly higher ALFF in the slow-4 band was observed in the frontal lobe,superior frontal gyrus,parietal lobe,right inferior parietal lobule,and left angular gyrus.CONCLUSION Our results suggest that the abnormal ALFF in pre-and post-ECT MDD patients may be associated with specific frequency bands.

Survivors of COVID-19 exhibit altered amplitudes of low frequency fluctuation in the brain: a resting-state functional magnetic resonance imaging study at 1-year follow-up

Although some short-term follow-up studies have found that individuals recovering from coronavirus disease 2019(COVID-19)exhibit anxiety,depression,and altered brain microstructure,their long-term physical problems,neuropsychiatric sequelae,and changes in brain function remain unknown.This observational cohort study collected 1-year follow-up data from 22 patients who had been hospitalized with COVID-19(8 males and 11 females,aged 54.2±8.7 years).Fatigue and myalgia were persistent symptoms at the 1-year follow-up.The resting state functional magnetic resonance imaging revealed that compared with 29 healthy controls(7 males and 18 females,aged 50.5±11.6 years),COVID-19 survivors had greatly increased amplitude of low-frequency fluctuation(ALFF)values in the left precentral gyrus,middle frontal gyrus,inferior frontal gyrus of operculum,inferior frontal gyrus of triangle,insula,hippocampus,parahippocampal gyrus,fusiform gyrus,postcentral gyrus,inferior parietal angular gyrus,supramarginal gyrus,angular gyrus,thalamus,middle temporal gyrus,inferior temporal gyrus,caudate,and putamen.ALFF values in the left caudate of the COVID-19 survivors were positively correlated with their Athens Insomnia Scale scores,and those in the left precentral gyrus were positively correlated with neutrophil count during hospitalization.The long-term follow-up results suggest that the ALFF in brain regions related to mood and sleep regulation were altered in COVID-19 survivors.This can help us understand the neurobiological mechanisms of COVID-19-related neuropsychiatric sequelae.This study was approved by the Ethics Committee of the Second Xiangya Hospital of Central South University(approval No.2020 S004)on March 19,2020.

AMPLITUDE OF LOW FREQUENCY FLUCTUATION AT DIFFERENT FREQUENCY BANDS IN EARLY AMNESTIC MILD COGNITIVE IMPAIRMENT: RESULTS FROM ADNI

We used resting-state functional magnetic resonance imaging(fMRI)to determine whether there are any abnormalities in different frequency bands between amplitude of low-frequency fluctuations(ALFF)and fractional ALFF(fALFF)and between 10 early amnestic mild cognitive impairment(EMCI)patients and eight normal controls participating in the Alzheimer’s Disease Neuroimaging Initiative(ADNI).We showed widespread difference in ALFF/fALFF between two frequency bands(slow-4:0.027-0.073 Hz,slow-5:0.01-0.027 Hz)in many brain areas including posterior cingulate cortex(PCC),medial prefrontal cortex(MPFC),suprasellar cistern(SC)and ambient cistern(AC).Compared to the normal controls,the EMCI patients showed increased ALFF values in PCu,cerebellum,occipital lobe and cerebellum posterior lobe in frequency band slow-4.While in frequency band slow-5,the EMCI patients showed decreased ALFF values in temporal lobe,left cerebrum and middle temporal gyrus5.Moreover,the EMCI patients showed increased fALFF values in frontal lobe and inferior frontal gyrus in band slow-5.While in frequency band slow-4,the EMCI patients showed decreased fALFF values in limbic lobe,cingulate gyrus and corpus callosum.These results demonstrated that EMCI patients had widespread abnormalities of amplitude of LFF in different frequency bands.

Dynamic alterations of amplitude of low-frequency fluctuations in patients with chronic neck pain

Background:The pathogenesis of neck pain in the brain,which is the fourth most common cause of disability,remains unclear.Furthermore,little is known about the characteristics of dynamic local functional brain activity in cervical pain.Objective:The present study aimed to investigate the changes of local brain activity caused by chronic neck pain and the factors leading to neck pain.Methods:Using the amplitude of low-frequency fluctuations(ALFF)method combined with sliding window approach,we compared local brain activity that was measured by the functional magnetic resonance imaging(fMRI)of 107 patients with chronic neck pain(CNP)with that of 57 healthy control participants.Five pathogenic factors were selected for correlation analysis.Results:The group comparison results of dynamic amplitude of low-frequency fluctuation(dALFF)variability showed that patients with CNP exhibited decreased dALFF variability in the left inferior temporal gyrus,the middle temporal gyrus,the angular gyrus,the inferior parietal marginal angular gyrus,and the middle occipital gyrus.The abnormal dALFF variability of the left inferior temporal gyrus was negatively correlated with the average daily working hours of patients with neck pain.Conclusions:The findings indicated that the brain regions of patients with CNP responsible for audition,vision,memory,and emotion were subjected to temporal variability of abnormal regional brain activity.Moreover,the dALFF variability in the left inferior temporal gyrus might be a risk factor for neck pain.This study revealed the brain dysfunction of patients with CNP from the perspective of dynamic local brain activity,and highlighted the important role of dALFF variability in understanding the neural mechanism of CNP.

Low-frequency fluctuation in continuous real-time feedback of finger force:a new paradigm for sustained attention

Objective Behavioral studies have suggested a low-frequency（0.05 Hz） fluctuation of sustained attention on the basis of the intra-individual variability of reaction-time.Conventional task designs for functional magnetic resonance imaging（fMRI） studies are not appropriate for frequency analysis.The present study aimed to propose a new paradigm,real-time finger force feedback（RT-FFF）,to study the brain mechanisms of sustained attention and neurofeedback.Methods We compared the low-frequency fluctuations in both behavioral and fMRI data from 38 healthy adults（19 males;mean age,22.3 years）.Two fMRI sessions,in RT-FFF and sham finger force feedback（S-FFF） states,were acquired（TR 2 s,Siemens Trio 3-Tesla scanner,8 min each,counter-balanced）.Behavioral data of finger force were obtained simultaneously at a sampling rate of 250 Hz.Results Frequency analysis of the behavioral data showed lower amplitude in the lowfrequency band（0.004-0.104 Hz） but higher amplitude in the high-frequency band（27.02-125 Hz） in the RT-FFF than the S-FFF states.The mean finger force was not significantly different between the two states.fMRI data analysis showed higher fractional amplitude of low-frequency fluctuation（fALFF） in the S-FFF than in the RT-FFF state in the visual cortex,but higher fALFF in RT-FFF than S-FFF in the middle frontal gyrus,the superior frontal gyrus,and the default mode network.Conclusion The behavioral results suggest that the proposed paradigm may provide a new approach to studies of sustained attention.The fMRI results suggest that a distributed network including visual,motor,attentional,and default mode networks may be involved in sustained attention and/or real-time feedback.This paradigm may be helpful for future studies on deficits of attention,such as attention deficit hyperactivity disorder and mild traumatic brain injury.

Local synchronization and amplitude of the fluctuation of spontaneous brain activity in attention-deficit/hyperactivity disorder:a resting-state fMRI study

Regional homogeneity（ReHo）and the amplitude of low-frequency fluctuation（ALFF）are two approaches to depicting different regional characteristics of resting-state functional magnetic resonance imaging（RS-fMRI）data.Whether they can complementarily reveal brain regional functional abnormalities in attention-deficit/hyperactivity disorder（ADHD）remains unknown.In this study,we applied ReHo and ALFF to 23 medication-na ve boys diagnosed with ADHD and 25 age-matched healthy male controls using whole-brain voxel-wise analysis.Correlation analyses were conducted in the ADHD group to investigate the relationship between the regional spontaneous brain activity measured by the two approaches and the clinical symptoms of ADHD.We found that the ReHo method showed widely-distributed differences between the two groups in the fronto-cingulo-occipitocerebellar circuitry,while the ALFF method showed a difference only in the right occipital area.When a larger smoothing kernel and a more lenient threshold were used for ALFF,more overlapped regions were found between ALFF and ReHo,and ALFF even found some new regions with group differences.The ADHD symptom scores were correlated with the ReHo values in the right cerebellum,dorsal anterior cingulate cortex and left lingual gyrus in the ADHD group,while no correlation was detected between ALFF and ADHD symptoms.In conclusion,ReHo may be more sensitive to regional abnormalities,at least in boys with ADHD,than ALFF.And ALFF may be complementary to ReHo in measuring local spontaneous activity.Combination of the two may yield a more comprehensive pathophy-siological framework for ADHD.

Neuropathological characteristics of abnormal white matter functional signaling in adolescents with major depression

BACKGROUND Major depression disorder(MDD)constitutes a significant mental health concern.Epidemiological surveys indicate that the lifetime prevalence of depression in adolescents is much higher than that in adults,with a corresponding increased risk of suicide.In studying brain dysfunction associated with MDD in adolescents,research on brain white matter(WM)is sparse.Some researchers even mistakenly regard the signals generated by the WM as noise points.In fact,studies have shown that WM exhibits similar blood oxygen level-dependent signal fluctuations.The alterations in WM signals and their relationship with disease severity in adolescents with MDD remain unclear.AIM To explore potential abnormalities in WM functional signals in adolescents with MDD.METHODS This study involved 48 adolescent patients with MDD and 31 healthy controls(HC).All participants were assessed using the Patient Health Questionnaire-9 Scale and the mini international neuropsychiatric interview(MINI)suicide inventory.In addition,a Siemens Skyra 3.0T magnetic resonance scanner was used to obtain the subjects'image data.The DPABI software was utilized to calculate the WM signal of the fractional amplitude of low frequency fluctuations(fALFF)and regional homogeneity,followed by a two-sample t-test between the MDD and HC groups.Independent component analysis(ICA)was also used to evaluate the WM functional signal.Pearson’s correlation was performed to assess the relationship between statistical test results and clinical scales.RESULTS Compared to HC,individuals with MDD demonstrated a decrease in the fALFF of WM in the corpus callosum body,left posterior limb of the internal capsule,right superior corona radiata,and bilateral posterior corona radiata[P<0.001,family-wise error(FWE)voxel correction].The regional homogeneity of WM increased in the right posterior limb of internal capsule and left superior corona radiata,and decreased in the left superior longitudinal fasciculus(P<0.001,FWE voxel correction).The ICA results of WM overlapped with those of regional homogeneity.The fALFF of WM signal in the left posterior limb of the internal capsule was negatively correlated with the MINI suicide scale(P=0.026,r=-0.32),and the right posterior corona radiata was also negatively correlated with the MINI suicide scale(P=0.047,r=-0.288).CONCLUSION Adolescents with MDD involves changes in WM functional signals,and these differences in brain regions may increase the risk of suicide.

早发抑郁患者功能磁共振成像对下脑区静息态自发活动与疾病严重程度的相关性研究

目的:探索早发性抑郁症(EOD)患者脑区自发活动与疾病严重程度的关系。方法:选取20例EOD患者纳入观察组,另选20名健康受检者纳入健康对照组,对两组分别进行3.0T磁共振成像(MRI)静息态扫描,比较分析两组受检者脑区的低频振幅以及比率低频振幅特征,将对比所得差异性脑区的均值与汉密尔顿抑郁量表(HAMD)总分做相关性分析,观察其临床严重程度与差异性脑区活动的相关性。结果:观察组患者的右侧颞中回、背外侧额上回、右侧岛叶、左侧枕上回及右侧扣带回的低频振幅(ALFF)值随着HAMD-17评分增加而逐渐增强,而在右侧颞上回颞级、左侧颞中回颞级及左侧海马区域随着HAMD-17评分增加而减弱;观察组患者的右侧岛叶、左侧扣带回、右侧扣带回、左侧眶部额中回以及左侧额中回的比率低频振幅(fALFF)值随着HAMD-17评分增加而逐渐增强,在右侧距状裂、右侧舌回、右侧梭状回及右侧缘上回区域随着HAMD-17评分增加而逐渐为减弱,与健康对照组比较差异均有统计学意义(AlphaSim校正,P<0.05,cluster size>405 mm^3,蒙特卡罗校正)。结论:早发性抑郁患者在前额叶、扣带回、部分枕以及颞叶脑区自发活动的改变与抑郁症的严重程度存在相关性。

皮质发育畸形术前定位致灶的静息态功能MRI初步研究

目的探讨基于局部一致性(Re Ho)、低频振幅(ALFF)和低频振幅分数(f ALFF)的静息态功能MRI(RS-f MRI)是否具有术前定位皮质发育畸形(MCD)患者致灶的能力。方法 MCD患者10例行RS-f MRI检查,静息态数据经预处理和分析后得到的Re Ho、ALFF和f ALFF激活图,与视频脑电图(VEEG)、正电子发射断层显像(PET)、MRI及综合评估的致灶结果比较。比较患者术后结果与静息态异常激活图结果。结果 RS-f MRI致灶定位结果分别与6例VEEG、8例PET、6例MRI以及7例最终综合评估的致灶定位结果一致。6例接受手术治疗的患者(包括2例MRI检查阴性)均发现异常的局部激活图,术后经病理证实为皮质发育畸形(2例灰质异位和4例局灶性皮质发育不良)。结论基于Re Ho、ALFF及f ALFF分析方法的RS-f MRI具有定位MCD患者致灶的能力。

旋转手法治疗对腰椎间盘突出症患者静息态脑功能的影响

目的:观察旋转手法治疗对腰椎间盘突出症患者静息态脑功能的影响。方法:纳入符合条件的17例腰椎间盘突出症患者,均使用旋转手法治疗。采集患者治疗前后的功能磁共振数据,每次治疗前及治疗后分别记录患者的视觉模拟评分法(VAS)评分。结果:治疗后,患者双侧枕上回、左侧枕中回、双侧楔叶、左侧踞状回的低频振荡振幅(ALFF)较治疗前增高,差异有统计学意义(P<0.05)。每次治疗前的VAS评分与每次治疗后的VAS评分均持续下降,差异均有统计学意义(P<0.01)。4次治疗后的VAS评分均低于同期治疗前,差异有统计学意义(P<0.01)。第2次治疗前与第1次治疗后、第3次治疗前与第2次治疗后以及第4次治疗前与第3次治疗后的VAS评分比较,差异均有统计学意义(P<0.05)。结论:旋转手法治疗腰椎间盘突出症,镇痛效果明显,可能通过激活部分脑区实现。

大学新生网络成瘾的静息态脑功能结构特征

为了找出涉及网络成瘾(IAD)机制的关键脑区,同时探查IAD者脑功能和结构特征,招募IAD组和对照组大学新生被试,扫描和比较分析静息态功能磁共振和结构磁共振数据.结果表明:网络成瘾者的右枕叶和右舌回的静息态脑自发活性呈亢进,左眶额叶呈降低;右海马旁回、右枕叶和右舌回的皮层灰质密度显著降低;右枕叶的功能和结构异常水平都与网络成瘾量表(IAT)分显著相关.右枕叶在网络成瘾的发病机制中的作用值得进一步探察.

静息态脑功能低频振幅预测早期精神分裂症患者视觉信息处理速度研究

目的建立基于静息态功能磁共振(functional magnetic resonance imaging,fMRI)低频振幅(amplitude of low-frequency fluctuation,ALFF)数据预测早期精神分裂症(schizophrenia,SZ)患者视觉信息处理速度(visual information processing speed,VIPS)的模型。方法纳入31例早期SZ患者和33名正常对照者,用连线测验(trail making test,TMT)评估受试者VIPS,使用支持向量回归(support vector regression,SVR)以两组ALFF差异脑区作为模板定量预测患者组VIPS评分。结果两组的VIPS差异存在统计学意义(P<0.01)。与对照组相比,患者组ALFF值升高主要分布在边缘叶(P<0.01,AlphaSim校正),而ALFF值降低主要分布在额叶、顶叶和枕叶(P<0.01,AlphaSim校正)。SVR结果显示,SZ异常脑区ALFF值可有效预测VIPS(r=0.62,P=0.04)。SVR过程中权重高的脑区包括右侧楔前叶、右侧辅助运动区和右侧中央后回,其中,右侧楔前叶ALFF值与VIPS相关(r=0.50,P<0.01)。结论早期SZ患者部分异常脑区自发活动与VIPS相关且可有效预测VIPS,这提示脑区自发活动可能是SZ患者VIPS受损的预测指标和客观生物标志物。

额叶肿瘤静息态功能磁共振比率低频振幅的研究

采用静息态下功能磁共振成像(f MRI)比率低频振幅(f ALFF)测量技术,从能量的角度对额叶肿瘤患者与正常对照组进行比较分析,探讨额叶肿瘤患者认知功能失调的病理机制。本研究分别对14例额叶肿瘤患者和14例性别、年龄及受教育程度均相匹配的健康对照组进行静息态f MRI扫描,用f ALFF算法进行比较分析。结果显示额叶肿瘤组同正常对照组相比,额叶肿瘤组f ALFF值升高的脑区主要集中在右侧眶额回、右侧颞叶、右侧辅助运动区、左侧海马旁回、左侧后扣带回、左侧内侧和旁扣带及旁中央小叶,f ALFF值降低的脑区主要集中在双侧背外侧额上回、双侧内侧额上回和小脑。研究结果显示在静息态下额叶肿瘤患者的额叶功能活动降低,这与额叶肿瘤部分组织的失活有关,而其余的默认网络区域、辅助运动区和旁中央小叶的活动增强,可能与额叶肿瘤脑认知功能失调及代偿作用有关。

有先兆偏头痛患者静息态功能磁共振成像研究

目的:采用静息态功能磁共振(rfMRI)技术描述研究有先兆偏头痛患者大脑结构和功能异常的MRI表现。方法:选取30例有先兆偏头痛患者作为观察组,30例无头痛健康人作为对照组。GE Discovery 750w 3.0T磁共振扫描仪,采用平面回波成像序列采集对象静息态功能MRI图像,计算每个被试者大脑相邻体素的局部一致性(regional homogeneity,ReHo)值,并对两组ReHo值组间进行比较,分析比较两组在静息状态下脑功能活动情况。结果:与对照组比较,有先兆偏头痛组多个脑区存在局部一致性ReHo降低,低频振幅(ALFF)变化,差异具有统计学意义(P<0.05)。结论:有先兆偏头痛患者头痛发作间期疼痛处理和调节相关脑区功能异常。

针刺足临泣对偏头痛低频振荡振幅的影响

目的:应用功能磁共振明确针刺足临泣对无先兆偏头痛脑功能区域低频振荡振幅的特征性影响。方法:选取2015年1月至2016年2月北京中医药大学东直门医院神经内科和北京中医药大学东方医院针灸科门诊就诊的无先兆偏头痛患者19例作为研究对象,在针刺前后进行静息态功能磁共振成像,匹配的18例健康受试者进行一次无针刺的功能磁共振扫描作为对照。分析偏头痛患者和正常受试者脑功能区的低频振荡振幅值差异以及患者针刺前后低频振荡振幅值的变化。结果:与健康对照组比较,无先兆偏头痛患者低频振荡振幅值显著增强的脑区为海马、海马旁回、右侧颞上回等脑区,显著减弱的脑区为左侧楔叶、顶上回等脑区;与针刺前比较,针刺后低频振荡振幅值显著增强的脑区为右侧中央前回和中央后回,显著减弱的脑区为右侧楔前叶、额中回等脑区;与健康对照组比较,无先兆偏头痛患者针刺足临泣穴后低频振荡振幅值显著增强的脑区为右侧的中央前回、中央后回等脑区,显著减弱的脑区为左侧楔叶、楔前叶等脑区。结论:针刺足临泣穴对无先兆偏头痛多个脑区的功能活动异常的起特征性调节作用,这可能为针刺干预的疗效机制提供功能影像学支持。

首诊孤独症患儿功能性磁共振成像脑自发活动低频振幅图和低频振幅分数图上的区域性异常改变研究

目的:探讨孤独症首次功能性磁共振成像(fMRI)诊断儿童脑自发活动低频振幅分数(fALFF)图及低频振幅(ALFF)图上的区域性异常变化研究。方法:选择医院收治的40例孤独症首诊儿童,并将其纳入观察组,将同期体检的40名健康儿童纳入健康对照组,两组均在静息状态下应用3.0T TX型超导磁共振扫描仪进行梯度回波序列采集血氧依赖水平(BOLD)的脑功能成像数据,予以空间标准化、校正头动及预处理时间校正,6 mm高斯核平滑运算,采用REST脑功能软件处理数据,得到两组的fALFF图和ALFF图,比较两组的图像差别。结果:观察组患儿右侧颞回、颞极中部ALFF值显著低于健康对照组,差异有统计学意义(t=11.9085,P<0.05);观察组患儿的左侧颞回、梭状回枕中回、右侧颞回、右侧颞极中部、颞中以及下回的fALFF图值显著低于健康对照组,差异均有统计学意义(t=17.1685,t=5.9370,t=6.738;P<0.05);观察组患儿双侧小脑内侧、小脑蚯部及脑干部的fALFF图值显著高于健康对照组,差异有统计学意义(t=5.2935,P<0.05)。结论:fMRI静息状态下的fALFF图和ALFF图可发现孤独症患儿的多脑区功能异常变化,可能与孤独症的核心症状密切相关,可作为评估低龄儿童脑功能发育的重要方式。

老年人声音诱发闪光错觉的大脑静息态低频振幅

声音诱发闪光错觉(sound-induced flash illusion,SiFI)是一种听觉占主导性的多感觉整合现象,即当视觉闪光伴随不相等数量的听觉声音在100 ms内相继或同时呈现时,个体会错觉性地知觉到视觉闪光的个数与听觉声音的数量相等。本研究分别将老年人群体和年轻人群体的声音诱发闪光错觉量(裂变错觉和融合错觉)与全脑的静息态低频振幅(amplitude of low-frequency fluctuation,ALFF)进行相关分析,考察老年人群体声音诱发闪光错觉效应与大脑静息状态自发活动区域的关系。结果发现,无论是裂变错觉还是融合错觉,老年人声音诱发闪光错觉均增大。对于裂变错觉,老年人的错觉量与内侧前额叶皮层的自发活动呈显著正相关;对于融合错觉,老年人的错觉量与额下回、额中回和颞下回的自发活动呈显著正相关,与枕上回和舌回的自发活动呈现显著的负相关。结果表明,老年人声音诱发闪光错觉量增大的原因与大脑中多个脑区的静息态自发活动存在关系。