脑语言区附近胶质瘤术后认知功能障碍的临床和fMRI研究

目的:通过临床方法和脑功能磁共振成像(fMRI)技术探讨脑语言区附近脑区的认知功能.方法:对18例左侧语言区附近胶质瘤术后患者和18例临床资料相匹配健康者分别进行词语联想学习记忆量表测试;14名右利手健康志愿者进行相同任务的同时行fMRI扫描.并选用SPM 99软件进行数据分析和脑功能区定位.结果:胶质瘤术后患者词语联想学习记忆量表测试的成绩低于相匹配健康者(9.86±1.42± vs 18.79±2.30,P<0.001);fMRI结果显示任务编码和提取时所激活的脑区基本上集中于左半球语言区附近,左枕叶和左额上中回在任务编码时被显著激活(激活强度T值=13.87),而左顶叶则在记忆提取阶段被显著激活(T值=8.73).结论:人脑左侧语言区附近的脑区存在着与语言相关的语义记忆认知功能.     

针刺太溪穴 丘墟穴的脑功能磁共振成像研究

目的通过脑功能磁共振成像了解针刺太溪穴、丘墟穴的脑功能区信号变化情况。方法收集12名健康志愿者,实验采用组块刺激模式(静息阶段与刺激阶段交替出现,重复3次,每个阶段持续60 s),按照随机配对数字表,分别手法捻转行针刺右侧太溪穴、丘墟穴(捻转角度180°,频率1.5 Hz),使用SPM2对扫描后图像进行后处理以观察激活图、激活区的差别。结果在校正像情况下(组分析,FWE,0.05,K≥10),针刺太溪穴主要激活右侧颞上回BA22,左侧额中回BA46,其次为左右顶叶中央后回BA2、BA3,左额叶额下回BA45。针刺丘墟穴主要激活左侧颞上回BA42、BA22,其次为右顶叶中央后回BA40、BA43,右额叶额下回BA47,右颞叶颞上回BA22和左侧脑岛BA13。结论针刺与认知相关的太溪穴、丘墟穴的脑部主要激活区域位于额颞顶叶,这些激活区功能与听觉及智能相关。     

刺激养老穴激活脑功能区的不同阈值分析

目的为针刺的fMRI研究的统计分析选择合宜的的阈值。方法选取健康青年志愿者12例,进行刺激养老穴的fMRI研究,采用组块模式,使用SPM2对扫描后图像进行后处理,采用校正和非校正来统计分析脑功能激活情况。结果在校正象情况下（组分析,FWE,0．05,K≥10）,养老穴主要激活了左顶叶的顶下小叶BA40,右侧额叶的额下回BA45、BA46,其次为左侧颞中回、颞下回BA37,左额上回BA10。而非校正情况下,激活点非常广泛。结论在穴位的脑功能激活实验应选择校正像分析。     

认知策略调节尼古丁依赖者心理渴求的神经机制研究

目的:认知策略是一种有效的预防成瘾复吸的方法。因此,研究认知策略对尼古丁依赖者心理渴求的影响及其神经机制可以为探索治疗尼古丁依赖和复吸的心理学和药物干预措施提供理论指导。方法:本课题采用功能性磁共振(fMRI)对认知策略调节尼古丁依赖者心理渴求的神经机制进行研究。扫描范式为部分奖赏条件反射范式,在条件性刺激出现前,给予认知策略进行干预。扫描过程中,同时检测皮肤电导反应(SCR),扫描结束后要求受试者填写心理渴求问卷。结果:(1)行为学结果:戒断后的尼古丁依赖者暴露于伴随香烟的条件性刺激(CS+)时,皮肤电导反应显著增加,同时伴有心理渴求的增加。而认知策略可以非常有效地降低CS+诱发的皮肤电导反应及心理渴求。(2)神经影像学结果:戒断后的尼古丁依赖者暴露于CS+时,激活的脑功能区主要包括:双侧辅助运动区、双侧背外侧前额叶、右侧后扣带、左侧枕上回、左侧顶下小叶、左侧楔前叶、左侧顶上小叶、双侧纹状体尾状核。认知策略调节后,戒断后的尼古丁依赖者暴露于CS+时,激活脑区主要包括:右侧前扣带皮层、左侧旁海马回、右侧楔叶、左侧中央后回,左侧顶上小叶、左侧梭状回、右侧眶额皮层、双侧旁中央小叶、左侧中央前回、右侧额内侧回、右侧背外侧前额皮层。(3)相关性分析发现:认知策略调节心理渴求的下降与认知策略调节右侧前扣带皮层及右侧眶额皮层脑区的激活程度成正相关。结论:尼古丁依赖者对香烟产生期待及心理渴求增加时,与奖赏、记忆、动机相关的脑区激活。认知策略降低尼古丁依赖者对香烟的期待及心理渴求,该调节作用与做决定、情感及认知控制和注意力调节等相关的脑区激活有关。这一发现确定了调节尼古丁依赖者心理渴求的脑区,为治疗尼古丁依赖提供了靶点。     

慢性吸烟者大脑灰质体积变化的Meta分析

目的:用激活似然估计(Activation Likelihood Estimate)的Meta分析方法对慢性吸烟者的脑灰质变化情况进行分析和归纳。方法:首先,在Pub Med和Embase数据库中检索从2000年1月至2014年11月的基于体素的形态学分析方法(Voxel-based Morphometry)的慢性吸烟者灰质变化的研究,然后通过Ginger ALE软件包对所检索结果进行Meta分析和归纳。结果:检索得到528位慢性吸烟者和864例对照者的8篇研究。经过ALE分析可见,患者在右侧额中回(BA 10区)、右侧楔叶(BA 18区)、右侧扣带回前部(BA 32区)、左侧扣带回前部(BA 25区)、左侧额中回(BA 10区)、左侧额上回(BA 10区)和左侧岛叶(BA 13区)与健康对照组有显著差异。结论:我们的结果与前人运用信号差异图分析方法处理的结果类似,慢性吸烟者的额叶、岛叶、扣带回的灰质与对照组比较有显著差异,这一发现可加深我们对慢性吸烟者的脑结构改变的理解。     

军人PTSD患者治疗前后磁共振质子波谱的变化特点

目的观察军人创伤后应激障碍患者前额叶质子波谱的特点及与临床疗效的关系。方法对23例军人PTSD患者在入院24 h内行前额叶氢质子磁共振波谱(1H-MRS)扫描,并随机抽取某部25例健康官兵作为对照组。测定两组前额叶N-乙酰基天门冬氨酸(NAA)、谷氨酰胺复合物(CLx)、胆碱复合物(Cho)、肌醇(m I)、肌酸复合物(Cr)等化合物的含量,并观察其与临床疗效的关系。结果军人PTSD患者治疗前左侧前额叶NAA/Cr1.34±0.42、右侧1.36±0.48,正常对照组分别为1.58±0.64和1.55±0.59(P<0.01);研究组治疗前左侧前额叶Cho/Cr与对照组存在显著性差异(1.23±0.36 vs 1.14±0.31,P<0.05),而右侧差异无统计学意义(P>0.05);研究组治疗前后、对照组CLx、m I含量无显著性差异(P>0.05);研究组治疗前后左侧前额叶NAA/Cr(1.34±0.42 vs 1.49±0.52),存在显著性差异(P<0.05)。研究组治疗前后左侧前额叶NAA/Cr、Cho/Cr和右侧前额叶NAA/Cr与简明精神病评定量表(BPRS)评分减分值存在显著相关性(P<0.05)。结论军人PTSD患者双侧前额叶均存在NAA/Cr、Cho/Cr等代谢物质的改变,且与患者精神症状的严重程度密切相关,PTSD患者前额叶NAA/Cr、Cho/Cr的改变,可能是PTSD的发病机制之一。     

耳鸣患者PET显像的相关脑区探讨

目的：探讨耳鸣患者脑PET18 F-FDG代谢的相关脑区。方法通过对41例耳鸣患者及40例健康对照组进行PET-CT检查,行踪剂为18 F-FDG,结果用统计参数图(SPM)软件进行统计分析,确定与耳鸣相关脑区的解剖部位(BA)。结果耳鸣患者相关脑区主要位于左侧颞下回(BA20)、左侧颞中回(BA21)、左侧颞上回(BA22)、左侧腹侧后扣带皮层(BA24)、左侧颞极区(BA38)及右侧后外侧前额叶皮层(BA9)、右侧额极区(BA10)、右侧眶额回(BA11)、右侧颞下回(BA20)、右侧背侧前扣带皮层(BA32)、右侧海马旁皮层(BA36)、右侧梭状回(BA37)。结论耳鸣患者在中枢神经系统可能存在特定的投射区,主要位于边缘系统及额叶联合区,与主次级听觉皮层有一定关系。PET 为耳鸣提供了客观证据,有望成为耳鸣的客观检测方法。     

基于低频振幅算法对斜视性弱视儿童静息态功能磁共振成像的研究

目的:应用低频振幅(ALFF,fALFF)算法分析斜视性弱视儿童的脑功能磁共振图像(fMRI),并与对照组进行对比,观察患者脑活动的变化与异常。方法:在静息态下采集22位斜视性弱视儿童的fMRI和10名健康儿童(对照组),应用t检验对ALFF和fALFF进行组内和组间统计学分析。结果:斜视性弱视儿童患者低于正常对照脑区,主要分布于枕叶、颞叶、小脑后叶、小脑前叶、颞上回、顶叶、额叶、枕中回。结论:基于静息态的fMRI的ALFF和fALFF算法可以反映斜视性弱视儿童视皮层的变化和多脑区神经活动的变化。     

点按丘墟穴诱发脑卒中患者Bechterev屈曲反射的脑部激活效应

目的利用fMRI技术研究点按穴位法、常规方法诱发Bechterev屈曲反射法对脑功能重朔的影响。方法选择2014年4月~2015年9月期间,福建中医药大学附属康复医院住院和门诊符合纳入标准23例右脑脑卒中的患者,先后随机用点穴法及常规方法诱发左下肢Bechterev屈曲反射为刺激模式,采用组块设计,使用f MRI检测,利用spm8和xjview软件数据分析。结果本研究两种方法均以激活右侧大脑和左侧小脑为主;点穴方法对脑的激活主要有双侧小脑、双侧枕叶、双侧额叶、双侧颞叶,右中央旁小叶、右顶下小叶;常规方法对脑的激活主要有双侧小脑、双侧枕叶、双侧额叶,右中央旁小叶、右顶下小叶;点穴方法同常规方法比较,点穴方法激活脑区为左颞中回、右颞上回、右颞中回,常规方法未激活上述脑区,激活脑区结果差异有统计学意义(P<0.01,K>10)。结论本研究两种手法均能促进脑卒中患者脑部功能重组;点穴方法比常规手法更具有广泛激活效应,其更易激发Bechterev屈曲反射的机制可能是点穴手法促进颞叶功能区对运动功能的补偿。     

早发性抑郁患者基于低频振幅比特低频振幅下脑区功能活动特征研究

目的利用静息态磁共振技术对早发性抑郁症患者特异性脑区进行定位。方法选择20例我院收治的早发抑郁症患者20例和性别、年龄、受教育年限与患者相匹配的20名健康受试者(对照组),分别给予功能磁共振(fMRI)扫描,分别应用低频振幅(ALFF)、比特低频振幅(fALFF)方法进行基于体素的组间比较,分析其静息态脑功能的差异。结果 (1)在右侧缘上回、左侧额中回、右侧中央沟盖、左侧额上回及右侧眶部额中回的ALFF值强于健康对照组,在舌回、左侧中央前回、左侧小脑10区、左侧颞中回区域的ALFF值弱于健康对照组;(2)在右侧眶部额中回、右侧眶部额下回、右侧缘上回、右侧中央沟盖、左侧眶部额下回、左侧扣带回及右侧枕中回的fALFF强于健康对照组,在左侧中央前回、左侧中央后回、右侧楔叶及右侧梭状回区域的fALFF值弱于健康对照组。结论早发性抑郁患者在前额叶、扣带回、边缘系统等多个区域脑自发活动强于健康受试者;在大脑额叶后部、颞叶前部、枕叶及小脑部分区域等多个区域脑自发活动弱于正常受试者;且ALFF及fALFF算法均存在相对一致性,显示这些特定脑区的脑自发活动异常可能是早发抑郁的神经生物学基础。     

fMRI脑功能成像技术用于网络游戏成瘾诊断测评

目的运用蹦RI脑功能成像技术,总结网络游戏成瘾青少年的神经影像学改变,为其诊断和治疗提供客观依据。方法选择12名网络游戏成瘾青少年（IAD组）和12名正常青少年（对照组）参与本研究,两组被试者分别观看网络游戏相关图片和中性图片,同时采用fMRI技术扫描,获取被试者的大脑活动信号,使用SPM5软件分析处理。结果与观看中性图片时比较,IAD组观看游戏图片时双侧背外侧前额叶、扣带回前部、顶下小叶、颞下回、小脑、右侧岛叶及右侧角回激活增多。IAD组观看游戏图片时以下区域激活增多：双侧背外侧前额叶、双侧颞叶、小脑、右侧顶下小叶、右侧楔叶、左侧海马、海马旁回、左侧尾状核;对照组观看游戏图片时全脑未见激活增多。结论网络游戏成瘾的青少年脑功能成像影像改变与正常青少年存在差异,为网络成瘾的诊断测评标准提供了新的客观依据。     

The role of 5-HT in response inhibition and re-engagement

In animal and human research, the neurotransmitter serotonin (5-HT) has been implicated in inhibitory control. Using functional magnetic resonance imaging (fMRI), the present study investigated the acute effects of pharmacological modulation of the serotonergic system on brain activation during response inhibition and re-engagement in healthy human volunteers. In a randomized double-blind placebo-controlled cross-over design 14 men received either a single oral dose of the selective serotonin reuptake inhibitor (SSRI) escitalopram (10 mg) or a placebo. At the time of the expected plasma peak concentration, participants performed a stop–change task during fMRI. Escitalopram did not affect behavioural performance, since the main effect did not reveal significant differences between reaction times of go-, stop- or change-trials. During successful response inhibition, escitalopram, however, was associated with enhanced brain activation in right prefrontal cortex, right supplementary/pre-motor and bilateral cingulate cortex, and subcortical regions. During inhibition failures, escitalopram also modulated a broad network of brain regions, including anterior cingulate, right parietal cortex, right orbitofrontal cortex, and areas in right temporal cortex and subcortical regions. During response re-engagement escitalopram increased brain activation in right inferior frontal gyrus and precuneus as well as in left middle temporal gyrus. The results implicate the involvement of 5-HT in neural regulation of response inhibition and re-engagement. This study also provides evidence that 5-HT affects both action restraint and action cancellation through modulation of activation of brain areas. The results support the view for a fronto-striatal circuitry for response inhibition in conjunction with serotonin.     

Regional cerebral blood flow in alcohol-induced violence: a case study

A case is presented of a 20-year-old man who became violent on many occasions after ingesting alcohol. On one occasion he committed an armed robbery. Two brain SPECT studies were performed: one when he was alcohol free, and one after he ingested alcohol in the same pattern as the night of the crime. The "alcohol free" study revealed marked hyperactivity in the cingulate gyrus, right and left lateral frontal lobes, right and left lateral parietal lobes and the right lateral temporal lobe. The "alcohol intoxication" study showed an overall dampening effect on the hyperactive areas of the brain, with only the anterior cingulate gyrus showing excessive activity. In addition, the right and left prefrontal cortex became hypoperfused, decreasing impulse control and judgment, as did the left and right temporal lobes, increasing the likelihood for aggression. This study suggests that this man may have been "self-medicating" an overactive brain, but in the process induced a state that increased the likelihood for aggressive behavior. This case study suggests the need for further research in the area of alcohol-induced violence and the potential usefulness of SPECT imaging, although no conclusions can be drawn from one case.     

Cholinergic agonism alters cognitive processing and enhances brain functional connectivity in patients with multiple sclerosis

The aim of this study is to define mechanisms underlying the pharmacological effects of brain cholinesterase inhibition on cognitive function in patients with multiple sclerosis (MS). Both a Stroop task and an N-back task were used to probe the changes in brain activity using functional magnetic resonance imaging (fMRI) in a single (investigator)-blind, crossover treatment design studying 15 patients with multiple sclerosis (12 relapsing remitting, 3 secondary progressive) taking rivastigmine (4.5 mg po bid) and domperidone (10 mg po qd) or domperidone alone. Administration of rivastigmine increased Stroop functional magnetic resonance imaging activation in the right inferior frontal gyrus for the Stroop task (P < 0.05, corrected). Incremental functional magnetic resonance imaging activation with progressively greater N-back task difficulty was enhanced by rivastigmine in prefrontal and parietal cortical regions (P < 0.01, ANOVA). Functional connectivity analysis of the N-back functional magnetic resonance imaging data based on correlations between pair-wise interregional activations showed increased connectivity between left to right prefrontal, anterior cingulate to left prefrontal and right parietal to right prefrontal regions with rivastigmine (P < 0.05, corrected). Although there were no statistically significant changes in the neuropsychological task performance with rivastigmine in this small study, 11 of 15 patients showed improvements, whereas only 4 of 15 patients showed decline in performance (P = 0.07). With regard to the previous data, these findings suggest different patterns of brain response to lower dose acute and higher dose chronic administration of rivastigmine in patients with multiple sclerosis. They showed that rivastigmine enhances the prefrontal function and alters the functional connectivity associated with cognition. We interpret this as evidence for greater efficiency of brain information transfer that should increase confidence in a potentially beneficial clinical therapeutic effect.     

The influence of recency of use on fMRI response during spatial working memory in adolescent marijuana users

Some neurocognitive recovery occurs within a month of abstinence from heavy marijuana use, yet functional magnetic resonance imaging (fMRI) has revealed altered activation among recent and abstinent adult users. We compared fMRI response during a spatial working memory (SWM) task between adolescent marijuana users with brief and sustained durations of abstinence. Participants were 13 recent users (two to seven days abstinent), 13 abstinent users (27 to 60 days abstinent), and 18 nonusing controls, all ages 15 to 18. Groups were similar on demographics, had no psychiatric or medical disorders, and user groups were similar on substance histories. Teens performed a two-back SWM task during fMRI. Recent users showed greater fMRI response in medial and left superior prefrontal cortices, as well as bilateral insula. Abstinent users had increased response in the right precentral gyrus (clusters > or = 1328 microl, p < .05). Results suggest that adolescents who recently used marijuana show increased brain activity in regions associated with working memory updating and inhibition. This study preliminarily suggests that (1) recent marijuana use may disrupt neural connections associated with SWM and result in compensatory brain response, and (2) sustained abstinence from marijuana may be associated with improvements in SWM response among adolescents.     

The Quiescent Heroin Scene: Incidence and Prevalence in the San Francisco Bay Area

Abstract

A case is presented of a 20-year-old man who became violent on many occasions after ingesting alcohol. On one occasion he committed an armed robbery. Two brain SPECT studies were performed: one when he was alcohol free, and one after he ingested alcohol in the same patternas the night of the crime. The “alcohol free” study revealed marked hyperactivity in the eingulate gyrus, right and left lateral frontal lobes, right and left lateral parietal lobes and the right lateral temporallobe. The “alcohol intoxication” study showed an overall dampening effect on the hyperactive areas of the brain, with only the anterior cingulate gyrus showing excessive activity. In addition, the right and left prefrontal cortex became hypoperfused, decreasing impulse control and judgment, as did the left and right temporal lobes, increasing the likelihood for aggression. This study suggests that this man may have been “self-medicating” an overactive brain, but in the process induced a state that increased the likelihood for aggressive behavior. This case study suggests the need for further research in the area of alcohol-induced violence and the potential usefulness of SPECT imaging, although no conclusions can be drawn from one case.     

Functional MRI of inhibitory processing in abstinent adolescent marijuana users

Background Marijuana intoxication appears to impair response inhibition, but it is unclear if impaired inhibition and associated brain abnormalities persist after prolonged abstinence among adolescent users. We hypothesized that brain activation during a go/no-go task would show persistent abnormalities in adolescent marijuana users after 28 days of abstinence. Methods Adolescents with (n = 16) and without (n = 17) histories of marijuana use were compared on blood oxygen level dependent (BOLD) response to a go/no-go task during functional magnetic resonance imaging (fMRI) after 28 days of monitored abstinence. Participants had no neurological problems or Axis I diagnoses other than cannabis abuse/dependence. Results Marijuana users did not differ from non-users on task performance but showed more BOLD response than non-users during inhibition trials in right dorsolateral prefrontal, bilateral medial frontal, bilateral inferior and superior parietal lobules, and right occipital gyri, as well as during “go” trials in right prefrontal, insular, and parietal cortices (p < 0.05, clusters > 943 μl). Differences remained significant even after controlling for lifetime and recent alcohol use. Conclusions Adolescent marijuana users relative to non-users showed increased brain processing effort during an inhibition task in the presence of similar task performance, even after 28 days of abstinence. Thus, increased brain processing effort to achieve inhibition may predate the onset of regular use or result from it. Future investigations will need to determine whether increased brain processing effort is associated with risk to use.     

Midazolam decreases cerebral blood flow in the left prefrontal cortex in a dose-dependent fashion

Midazolam, a short-lived benzodiazepine producing sedation and reversible anterograde amnesia, was administered intravenously to 14 healthy male volunteers. Regional cerebral blood flow (rCBF) was measured using positron emission tomography (PET) with intravenous H2 15O at either a 'high' midazolam EEG effect (EEG signs of stage 2 sleep), or 'low' midazolam EEG effect (increase in EEG beta power only). Memory tests administered following PET scans showed significant drug-induced impairment in learning and retrieval at the same drug concentration at which PET images were acquired. Statistical parametric mapping was used to identify regions where rCBF changes after drug administration were significantly different in the high- vs. low- effect groups. Dosexcondition interactions were found in the left dorsolateral prefrontal cortex [Brodmann's areas (BA) 9 and 46], bilateral orbital-frontal cortex (BA 47), the left middle temporal gyrus (BA 22) and the right hippocampus. The predominantly left frontal rCBF decreases occur in a region associated with semantic processing, working memory, and encoding of verbal material, a process preferentially affected by midazolam. Our interpretation is that rCBF changes in the hippocampus are unlikely to mediate the anterograde amnesia produced by midazolam. Although in the present study PET images were acquired during the resting state rather than during memory processing, these results underscore the need for further investigation relating to the interaction of midazolam with specific cognitive operations in these brain regions.