Structural magnetic resonance imaging

结构磁共振成像
  • 文章类型: Journal Article
    间歇性theta爆发刺激(iTBS)是一种图案化形式的兴奋性经颅磁刺激,作为缓解帕金森病(PD)患者临床缺陷的辅助治疗选择,已产生了令人鼓舞的结果。虽然已经证明iTBS影响多巴胺依赖性皮质纹状体可塑性,很少有研究研究iTBS诱导的临床增强的神经生物学机制。这里,我们的主要目标是验证iTBS在初级运动皮质(M1)双侧给药作为辅助治疗在降低PD中运动功能障碍和非运动症状评分方面是否有效.我们假设双侧M1-iTBS后的这些临床改善可能是由内源性多巴胺释放驱动的。可以重新平衡皮质兴奋性并恢复代偿性纹状体体积变化,导致纹状体-皮质-小脑功能连接增加,并积极影响神经胶质和神经可塑性。
    将对24名PD患者进行随机评估,双盲,假对照交叉研究,涉及在双侧M1上应用iTBS(M1iTBS)。接受药物治疗的患者将被随机分配接受真正的iTBS或对照(假)刺激,并将在双侧M1上经历5个连续的iTBS疗程(5天),间隔3个月的洗脱期。运动评估将在不同的随访中进行,并进行全面的神经认知评估;评估M1兴奋性;联合结构磁共振成像(MRI),静息状态脑电图和功能磁共振成像;以及神经轴突损伤的血清生物标志物定量,星形细胞反应性,iTBS前后的神经可塑性。
    这项研究的结果将有助于阐明M1iTBS治疗PD的效率,并进一步为改善这些患者的运动和非运动症状提供具体的神经生物学见解。这个新项目旨在使用非侵入性方法进行比以前的研究更详细的大脑结构和功能评估。有可能确定预后神经保护性生物标志物,并阐明M1iTBS诱导的皮质-基底神经节回路可塑性的结构和功能机制。我们的方法可能会显着优化神经调节范式,以确保最先进且可扩展的康复治疗,以减轻PD的运动和非运动症状。
    UNASSIGNED: Intermittent theta-burst stimulation (iTBS) is a patterned form of excitatory transcranial magnetic stimulation that has yielded encouraging results as an adjunctive therapeutic option to alleviate the emergence of clinical deficits in Parkinson\'s disease (PD) patients. Although it has been demonstrated that iTBS influences dopamine-dependent corticostriatal plasticity, little research has examined the neurobiological mechanisms underlying iTBS-induced clinical enhancement. Here, our primary goal is to verify whether iTBS bilaterally delivered over the primary motor cortex (M1) is effective as an add-on treatment at reducing scores for both motor functional impairment and nonmotor symptoms in PD. We hypothesize that these clinical improvements following bilateral M1-iTBS could be driven by endogenous dopamine release, which may rebalance cortical excitability and restore compensatory striatal volume changes, resulting in increased striato-cortico-cerebellar functional connectivity and positively impacting neuroglia and neuroplasticity.
    UNASSIGNED: A total of 24 PD patients will be assessed in a randomized, double-blind, sham-controlled crossover study involving the application of iTBS over the bilateral M1 (M1 iTBS). Patients on medication will be randomly assigned to receive real iTBS or control (sham) stimulation and will undergo 5 consecutive sessions (5 days) of iTBS over the bilateral M1 separated by a 3-month washout period. Motor evaluation will be performed at different follow-up visits along with a comprehensive neurocognitive assessment; evaluation of M1 excitability; combined structural magnetic resonance imaging (MRI), resting-state electroencephalography and functional MRI; and serum biomarker quantification of neuroaxonal damage, astrocytic reactivity, and neural plasticity prior to and after iTBS.
    UNASSIGNED: The findings of this study will help to clarify the efficiency of M1 iTBS for the treatment of PD and further provide specific neurobiological insights into improvements in motor and nonmotor symptoms in these patients. This novel project aims to yield more detailed structural and functional brain evaluations than previous studies while using a noninvasive approach, with the potential to identify prognostic neuroprotective biomarkers and elucidate the structural and functional mechanisms of M1 iTBS-induced plasticity in the cortico-basal ganglia circuitry. Our approach may significantly optimize neuromodulation paradigms to ensure state-of-the-art and scalable rehabilitative treatment to alleviate motor and nonmotor symptoms of PD.
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  • 文章类型: Journal Article
    UNASSIGNED:在基线和长期随访后,A型酒精中毒患者是否可以检测到局部脑容量的改变仍有待确认。因此,我们检查了基线时的体积变化,以及小的后续子样本中的纵向变化。
    UNASSIGNED:在基线时使用磁共振成像和基于体素的形态计量学对26名患者和24名健康对照进行了评估。其中17例患者和6例对照者在7年后重新评估.在基线,将患者的局部脑容量与对照组进行比较.在后续行动中,比较了三组:戒酒者(n=11,戒酒超过2年),复发者(n=6,禁欲<2年),和控制(n=6)。
    未经评估:检测到的横截面分析,在这两个时期,与戒断者相比,复发者的双侧尾状核体积更高。在弃权者中,纵向分析显示额叶中下回灰质容积恢复正常,在中间扣带回,而在call体以及前部和上部白质特定区域检测到白质体积恢复。
    未经评估:总的来说,本研究在横断面分析的基线和随访中发现复发AUD患者组中的尾状核较大.这一发现表明,较高的尾状体积可能是复发的候选危险因素。在特定的A型酒精依赖患者中,我们表明,在长期禁欲期间,前纹边缘GM和WM体积的长期恢复发生。这些结果支持正面电路在AUD中的关键作用。
    UNASSIGNED: Whether alteration in regional brain volumes can be detected in Type A alcoholics both at baseline and after a long follow-up remains to be confirmed. Therefore, we examined volume alterations at baseline, and longitudinal changes in a small follow-up subsample.
    UNASSIGNED: In total of 26 patients and 24 healthy controls were assessed at baseline using magnetic resonance imaging and voxel-based morphometry, among which 17 patients and 6 controls were re-evaluated 7 years later. At baseline, regional cerebral volumes of patients were compared to controls. At follow-up, three groups were compared: abstainers (n = 11, more than 2 years of abstinence), relapsers (n = 6, <2 years of abstinence), and controls (n = 6).
    UNASSIGNED: The cross-sectional analyses detected, at both times, higher caudate nuclei volumes bilaterally in relapsers compared to abstainers. In abstainers, the longitudinal analysis indicated recovery of normal gray matter volumes in the middle and inferior frontal gyrus, and in the middle cingulate, while white matter volumes recovery was detected in the corpus callosum and in anterior and superior white matter specific regions.
    UNASSIGNED: Overall, the present investigation revealed larger caudate nuclei in the relapser AUD patient group both at baseline and at follow-up in the cross-sectional analyses. This finding suggest that a higher caudate volume could be a candidate risk factor of relapse. In patients with specific type A alcohol-dependence, we showed that long-term recovery in fronto-striato-limbic GM and WM volumes occurs during long-term abstinence. These results support the crucial role of frontal circuitry in AUD.
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  • 文章类型: Journal Article
    UNASSIGNED:本研究探讨皮质下缺血性血管病(SIVD)-血管性认知障碍无痴呆(VCIND)患者的结构影像学改变及灰质体积改变与认知障碍领域的相关性,为早期诊断和治疗提供新的靶点。
    UNASSIGNED:我们的研究包括15例SIVD-正常认知障碍(SIVD-NCI)患者,63与SIVD-VCIND,26患有SIVD-血管性痴呆(SIVD-VD),和14个正常控制(NC)。收集所有参与者的T1加权图像,采用DPABI和SPM12软件对4组的灰质进行体素处理。费希尔的精确检验,采用单因素方差分析和Kruskal-WallisH检验评估所有临床和人口统计学数据,并比较各组中脑灰质萎缩的特征.最后,提取SIVD-VCIND的感兴趣区域(ROI),并对ROI与神经心理学量表结果进行Pearson相关性分析。
    UNASSIGNED:与NC相比,在双侧眶额回中观察到灰质萎缩的变化,右颞中回,颞上回,和SIVD-VCIND中的precuneus。左侧小脑6区、小脑1区、双侧丘脑灰质萎缩,右前叶,和SIVD-VD中的calcarine。与SIVD-VCIND相比,在SIVD-VD中观察到双侧丘脑的灰质萎缩变化(p<0.05,按家庭误差校正)。在SIVD-VCIND中,灰质总体积,双侧眶内侧额上回,右颞上回,颞中回,与波士顿命名测试得分呈正相关,而灰质总体积,右颞上回,颞中回与总体认知呈正相关。
    UNASSIGNED:结构磁共振成像可检测SIVD-VCIND和SIVD-VD患者灰质中广泛而细微的结构变化,为解释皮质下血管性认知障碍的发病机制提供有价值的证据,有助于SIVD-VCIND的早期诊断和SIVD-VD的早期预警。
    UNASSIGNED: This study explored the structural imaging changes in patients with subcortical ischemic vascular disease (SIVD)-vascular cognitive impairment no dementia (VCIND) and the correlation between the changes in gray matter volume and the field of cognitive impairment to provide new targets for early diagnosis and treatment.
    UNASSIGNED: Our study included 15 patients with SIVD-normal cognitive impairment (SIVD-NCI), 63 with SIVD-VCIND, 26 with SIVD-vascular dementia (SIVD-VD), and 14 normal controls (NC). T1-weighted images of all participants were collected, and DPABI and SPM12 software were used to process the gray matter of the four groups based on voxels. Fisher\'s exact test, one-way ANOVA and Kruskal-Wallis H test were used to evaluate all clinical and demographic data and compare the characteristics of diencephalic gray matter atrophy in each group. Finally, the region of interest (ROI) of the SIVD-VCIND was extracted, and Pearson correlation analysis was performed between the ROI and the results of the neuropsychological scale.
    UNASSIGNED: Compared to the NC, changes in gray matter atrophy were observed in the bilateral orbitofrontal gyrus, right middle temporal gyrus, superior temporal gyrus, and precuneus in the SIVD-VCIND. Gray matter atrophy was observed in the left cerebellar region 6, cerebellar crural region 1, bilateral thalamus, right precuneus, and calcarine in the SIVD-VD. Compared with the SIVD-VCIND, gray matter atrophy changes were observed in the bilateral thalamus in the SIVD-VD (p < 0.05, family-wise error corrected). In the SIVD-VCIND, the total gray matter volume, bilateral medial orbital superior frontal gyrus, right superior temporal gyrus, middle temporal gyrus, and precuneus were positively correlated with Boston Naming Test score, whereas the total gray matter volume, right superior temporal gyrus, and middle temporal gyrus were positively correlated with overall cognition.
    UNASSIGNED: Structural magnetic resonance imaging can detect extensive and subtle structural changes in the gray matter of patients with SIVD-VCIND and SIVD-VD, providing valuable evidences to explain the pathogenesis of subcortical vascular cognitive impairment and contributing to the early diagnosis of SIVD-VCIND and early warning of SIVD-VD.
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  • 文章类型: Journal Article
    未经证实:儿童生长激素缺乏症(GHD)是一种由生长激素/胰岛素样生长因子-1(IGF-1)轴受损引起的疾病,但GHD对儿童认知功能的影响,脑结构和脑功能尚未完全说明。
    未经评估:适用于儿童的完整韦克斯勒智能量表,结构成像,弥散张量成像,在11名GHD儿童和10名匹配的健康对照中评估了静息态功能磁共振成像。
    未经证实:(1)GHD组表现为中度认知障碍,IGF-1水平与认知指标呈正相关。(2)GHD组两个皮质脊髓束的平均扩散系数均显着增加。(3)IGF-1水平与左丘脑容积指标呈显著正相关,左苍白球和右壳核,但IGF-1水平与枕叶皮质厚度呈负相关。IGF-1水平与上纵束和右皮质脊髓束的部分各向异性呈负相关。(4)左侧海马/海马旁回区域同质性(ReHo)与IGF-1水平呈负相关;低频波动幅度(ALFF)和ReHo在中央旁叶,中央后回和中央前回也与IGF-1水平呈负相关,在该区域ALFF完全介导IGF-1对工作记忆指数的影响。
    未经证实:多个皮质下,皮质结构,区域神经活动可能受血清IGF-1水平的影响。其中,ALFF在中央旁叶,中央后回和中央前回完全介导IGF-1对工作记忆指数的影响。
    UNASSIGNED: Pediatric growth hormone deficiency (GHD) is a disease resulting from impaired growth hormone/insulin-like growth factor-1 (IGF-1) axis but the effects of GHD on children\'s cognitive function, brain structure and brain function were not yet fully illustrated.
    UNASSIGNED: Full Wechsler Intelligence Scales for Children, structural imaging, diffusion tensor imaging, and resting-state functional magnetic resonance imaging were assessed in 11 children with GHD and 10 matched healthy controls.
    UNASSIGNED: (1) The GHD group showed moderate cognitive impairment, and a positive correlation existed between IGF-1 levels and cognitive indices. (2) Mean diffusivity was significantly increased in both corticospinal tracts in GHD group. (3) There were significant positive correlations between IGF-1 levels and volume metrics of left thalamus, left pallidum and right putamen but a negative correlation between IGF-1 levels and cortical thickness of the occipital lobe. And IGF-1 levels negatively correlated with fractional anisotropy in the superior longitudinal fasciculus and right corticospinal tract. (4) Regional homogeneity (ReHo) in the left hippocampus/parahippocampal gyrus was negatively correlated with IGF-1 levels; the amplitude of low-frequency fluctuation (ALFF) and ReHo in the paracentral lobe, postcentral gyrus and precentral gyrus were also negatively correlated with IGF-1 levels, in which region ALFF fully mediates the effect of IGF-1 on working memory index.
    UNASSIGNED: Multiple subcortical, cortical structures, and regional neural activities might be influenced by serum IGF-1 levels. Thereinto, ALFF in the paracentral lobe, postcentral gyrus and precentral gyrus fully mediates the effect of IGF-1 on the working memory index.
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  • 文章类型: Journal Article
    背景:过度运动也可能导致运动成瘾(EXA),这对人们的身心健康是有害的。行为和神经影像学研究表明,成瘾性疾病本质上是动机问题。然而,关于EXA的神经心理学机制以及动机对EXA的影响知之甚少。
    方法:我们调查了130名具有EXA症状的定期运动参与者,以探索EXA的神经生物学基础及其与动机的关系。通过基于体素的形态计量学的全脑回归分析来评估EXA与灰质体积(GMV)之间的相关性。然后,提取区域脑功能,分析脑结构-功能-EXA的关系。最后,进行了中介分析,以进一步检测大脑之间的关系,动机,和EXA。
    结果:全脑相关分析表明,右眶额叶皮质(OFC)的GMV与EXA呈负相关。权利OFC的功能在EXA中起着间接作用,并通过OFC的GMV影响EXA。重要的是,正确OFC的GMV在能力动机与EXA的关系中起中介作用。即使在调整性别时,这些结果仍然很重要,年龄,身体质量指数,家庭社会经济地位,一般智力,颅内总容积,和头部运动。
    结论:应仔细解释结果,因为仅包括有EXA症状的患者。
    结论:这项研究为正确的OFC在EXA中的重要作用的潜在神经心理学机制提供了证据,并揭示了EXA中执行控制功能可能降低。
    Excessive exercise may also lead to exercise addiction (EXA), which is harmful to people\'s physical and mental health. Behavioral and neuroimaging studies have demonstrated that addictive disorders are essentially motivational problems. However, little is known about the neuropsychological mechanism of EXA and the effects of motivation on EXA.
    We investigated 130 regularly exercised participants with EXA symptoms to explore the neurobiological basis of EXA and its association with motivation. The correlation between EXA and gray matter volume (GMV) was evaluated by whole-brain regression analysis based on voxel-based morphometry. Then, regional brain function was extracted and the relationship between brain structure-function-EXA was analyzed. Finally, mediation analysis was performed to further detect the relationship between the brain, motivation, and EXA.
    Whole-brain correlation analyses showed that the GMV of the right orbitofrontal cortex (OFC) was negatively correlated with EXA. The function of the right OFC played an indirect role in EXA and affected EXA via the GMV of the OFC. Importantly, the GMV of the right OFC played a mediating role in the relationship between ability motivation and EXA. These results remain significant even when adjusting for sex, age, body mass index, family socioeconomic status, general intelligence, total intracranial volume, and head motion.
    The results should be interpreted carefully because only the people with EXA symptoms were included.
    This study provided evidence for the underlying neuropsychological mechanism of the important role of the right OFC in EXA and revealed that there may be a decrease in executive control function in EXA.
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  • 文章类型: Journal Article
    2型糖尿病(T2DM)是轻度认知障碍(MCI)的重要危险因素。结构磁共振成像(sMRI)是研究神经系统疾病中脑病理形态学损伤的有效且广泛使用的方法。在目前的研究中,我们旨在确定2型糖尿病患者中与MCI发病率相关的脑部区域改变.
    分别有18名T2DM患者伴MCI和不伴MCI(DMCI/T2DM),招募年龄/性别匹配的健康对照(HC)。通过Dr.brain™软件对所有个体的脑MRI图像进行自动量化的脑子结构体积分割和测量。总灰质的相对体积(TGM),总白质(TWM),三组之间比较了68对(左和右)大脑亚结构。对T2DM患者MCI相关脑区进行认知功能相关分析和受试者工作特征(ROC)曲线分析,我们利用机器学习方法对三组受试者进行了分类。
    在无MCI的T2DM患者和有MCI的T2DM患者中分别观察到10和27个具有显著相对体积改变的大脑亚结构(p<0.05)。与无MCI的T2DM患者相比,八个关键区域包括右眶前回,右钙和大脑,离开了库尼乌斯,左内嗅区,左额叶盖骨,右眶内侧回,右枕骨极,2型糖尿病合并MCI患者左颞极容积比显著降低(p<0.05)。其中,多个地区的体积比下降与蒙特利尔认知评估(MoCA)评分和简易精神状态检查(MMSE)评分呈正相关.通过随机森林算法基于这些区域作为特征进行的分类结果,T2DM/HC的准确率为69.4%,DMCI/HC72.2%,T2DM/DMCI69.4%。
    T2DM患者发生某些脑区域结构性病变,这种情况在T2DM合并MCI患者中更为严重。分割和测量整个大脑的系统方法对于预测T2DM患者MCI的存在具有潜在的临床价值。
    UNASSIGNED: Type 2 diabetes mellitus (T2DM) is an important risk factors for mild cognitive impairment (MCI). Structural magnetic resonance imaging (sMRI) is an effective and widely used method to investigate brain pathomorphological injury in neural diseases. In present study, we aimed to determine the brain regional alterations that correlated to the incidence of MCI in T2DM patients.
    UNASSIGNED: Eighteen T2DM patients with and without MCI (DMCI/T2DM) respectively, and eighteen age/gender-matched healthy controls (HC) were recruited. Brain MRI imagines of all the individuals were subjected to automatic quantified brain sub-structure volume segmentation and measurement by Dr. brain ™ software. The relative volume of total gray matter (TGM), total white matter (TWM), and 68 pairs (left and right) of brain sub-structures were compared between the three groups. Cognitive function correlation analysis and receiver operating characteristic (ROC) curve analysis were conducted in the MCI-related brain regions in T2DM patients, and we utilized a machine learning method to classify the three group of subjects.
    UNASSIGNED: 10 and 27 brain sub-structures with significant relative volumetric alterations were observed in T2DM patients without MCI and T2DM patients with MCI, respectively (p < 0.05). Compared with T2DM patients without MCI, eight critical regions include right anterior orbital gyrus, right calcarine and cerebrum, left cuneus, left entorhinal area, left frontal operculum, right medial orbital gyrus, right occipital pole, left temporal pole had significant lower volumetric ratio in T2DM patients with MCI (p < 0.05). Among them, the decrease of volumetric ratio in several regions had a positive correlation with Montreal Cognitive Assessment (MoCA) scores and Mini-Mental State Examination (MMSE) scores. The classification results conducted based on these regions as features by random forest algorithm yielded good accuracies of T2DM/HC 69.4%, DMCI/HC 72.2% and T2DM/DMCI 69.4%.
    UNASSIGNED: Certain brain regional structural lesions occurred in patients with T2DM, and this condition was more serious in T2DM patients combined with MCI. A systematic way of segmenting and measuring the whole brain has a potential clinical value for predicting the presence of MCI for T2DM patients.
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  • 文章类型: Journal Article
    背景:从结构磁共振成像获得的灰质(GM)密度和皮质厚度(CT)是代表性的GM形态学指标,通常用于阿尔茨海默病(AD)亚型研究。然而,这两种措施如何影响AD亚型的定义尚不清楚.
    方法:使用ADNI数据库中的180名AD患者来识别AD亚组。通过基于密度特征和CT特征的数据驱动策略识别亚型,分别。然后,分析了AD亚型定义中两个特征之间的相似性。
    结果:通过密度和CT特征发现了四种不同的亚型:弥漫性萎缩型AD,微小萎缩AD(MAD),左颞叶显性萎缩AD(LTAD),和枕骨保留AD。匹配的亚型在萎缩模式以及神经心理学和神经病理学特征方面表现出相对较高的相似性。关于载脂蛋白Eε2的携带,它们仅在MAD和LTAD上有所不同。
    结论:结果验证了不同的代表性形态学GM测量方法可以产生相似的AD亚型。同时,载脂蛋白E基因型的影响,不对称疾病进展,和它们的相互作用应被考虑并包括在AD亚型定义中。本研究为今后AD亚型研究的特征选择提供了有价值的参考。
    BACKGROUND: Gray matter (GM) density and cortical thickness (CT) obtained from structural magnetic resonance imaging are representative GM morphological measures that have been commonly used in Alzheimer\'s disease (AD) subtype research. However, how the two measures affect the definition of AD subtypes remains unclear.
    METHODS: A total of 180 AD patients from the ADNI database were used to identify AD subgroups. The subtypes were identified via a data-driven strategy based on the density features and CT features, respectively. Then, the similarity between the two features in AD subtype definition was analyzed.
    RESULTS: Four distinct subtypes were discovered by both density and CT features: diffuse atrophy AD, minimal atrophy AD (MAD), left temporal dominant atrophy AD (LTAD), and occipital sparing AD. The matched subtypes exhibited relatively high similarity in atrophy patterns and neuropsychological and neuropathological characteristics. They differed only in MAD and LTAD regarding the carrying of apolipoprotein E ε2.
    CONCLUSIONS: The results verified that different representative morphological GM measurement methods could produce similar AD subtypes. Meanwhile, the influences of apolipoprotein E genotype, asymmetric disease progression, and their interactions should be considered and included in the AD subtype definition. This study provides a valuable reference for selecting features in future studies of AD subtypes.
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  • 文章类型: Journal Article
    Adverse childhood experiences (ACEs) can affect later-life health outcomes via brain structural differences. However, there is no sufficient empirical evidence about whether brain morphological differences remain until old ages.
    We examined the association between ACEs and brain volumes among older individuals.
    Residents aged 65-84 years in Tokamachi City, Japan, were randomly recruited, and 491 participants were included in the analysis.
    ACEs were assessed with a self-reported questionnaire. The volumes of seven brain regions of interests were evaluated via structural magnetic resonance imaging.
    In total, 143 (27.1%) participants experienced one ACE and 33 (6.7%) two or more ACEs. Participants with two or more ACEs had a larger anterior cingulate cortex volume (B = 0.346, 95% confidence interval [CI] = 0.04 to 0.66) and smaller hippocampal (B = -0.287, 95% CI = -0.58 to 0.001) and amygdala (B = -0.313, 95% CI = -0.59 to -0.03) volumes. Interestingly, we observed a distinct association between deprivation and threat. That is, deprivation was associated with a smaller amygdala volume (B = -0.164, 95% CI = -0.32 to -0.01) and threat with a larger anterior cingulate cortex volume (B = 0.401, 95% CI = 0.11 to 0.70).
    ACEs were associated with the volumes of brain regions such as anterior cingulate cortex, hippocampus, and amygdala, which are responsible for emotion and self-regulation in older population. The effect of ACEs on the amygdala was commonly driven by deprivation experiences and that on the anterior cingulate cortex by threat.
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  • 文章类型: Journal Article
    Medial temporal lobe (MTL) atrophy is a key feature of Alzheimer\'s disease (AD), however, it also occurs in typical aging. To enhance the clinical utility of this biomarker, we need to better understand the differential effects of age and AD by encompassing the full AD-continuum from cognitively unimpaired (CU) to dementia, including all MTL subregions with up-to-date approaches and using longitudinal designs to assess atrophy more sensitively. Age-related trajectories were estimated using the best-fitted polynomials in 209 CU adults (aged 19-85). Changes related to AD were investigated among amyloid-negative (Aβ-) (n = 46) and amyloid-positive (Aβ+) (n = 14) CU, Aβ+ patients with mild cognitive impairment (MCI) (n = 33) and AD (n = 31). Nineteen MCI-to-AD converters were also compared with 34 non-converters. Relationships with cognitive functioning were evaluated in 63 Aβ+ MCI and AD patients. All participants were followed up to 47 months. MTL subregions, namely, the anterior and posterior hippocampus (aHPC/pHPC), entorhinal cortex (ERC), Brodmann areas (BA) 35 and 36 [as perirhinal cortex (PRC) substructures], and parahippocampal cortex (PHC), were segmented from a T1-weighted MRI using a new longitudinal pipeline (LASHiS). Statistical analyses were performed using mixed models. Adult lifespan models highlighted both linear (PRC, BA35, BA36, PHC) and nonlinear (HPC, aHPC, pHPC, ERC) trajectories. Group comparisons showed reduced baseline volumes and steeper volume declines over time for most of the MTL subregions in Aβ+ MCI and AD patients compared to Aβ- CU, but no differences between Aβ- and Aβ+ CU or between Aβ+ MCI and AD patients (except in ERC). Over time, MCI-to-AD converters exhibited a greater volume decline than non-converters in HPC, aHPC, and pHPC. Most of the MTL subregions were related to episodic memory performances but not to executive functioning or speed processing. Overall, these results emphasize the benefits of studying MTL subregions to distinguish age-related changes from AD. Interestingly, MTL subregions are unequally vulnerable to aging, and those displaying non-linear age-trajectories, while not damaged in preclinical AD (Aβ+ CU), were particularly affected from the prodromal stage (Aβ+ MCI). This volume decline in hippocampal substructures might also provide information regarding the conversion from MCI to AD-dementia. All together, these findings provide new insights into MTL alterations, which are crucial for AD-biomarkers definition.
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  • 文章类型: Journal Article
    以前的研究发现纹状体和小脑在尼古丁依赖中起着重要作用,分别。在重度吸烟者中,然而,小脑-纹状体回路静息态功能连接在尼古丁依赖中的作用尚不清楚.本研究旨在使用结构和功能磁共振成像来探讨纹状体和小脑之间的回路在重度吸烟者成瘾中的作用。研究了23名重度吸烟者和23名健康对照者的小脑-纹状体回路的灰质体积差异和静息状态功能连通性差异。使用Fagerström检验评估重度吸烟者和健康对照者的香烟依赖性。然后,我们应用中介分析来检验重度吸烟者纹状体和小脑之间的静息态功能连接是否中介了纹状体形态计量学与尼古丁依赖之间的关系.与健康对照相比,重度吸烟者的大脑灰质体积显著减少(双侧),并且在尾状中显著增加(双侧)。基于种子的静息状态功能连通性分析显示,双侧尾状之间的静息状态功能连通性明显更高。左小脑,和重度吸烟者的右颞中回。小脑-纹状体静息状态功能连接完全介导了重度吸烟者纹状体形态计量学与尼古丁依赖之间的关系。重度吸烟者在纹状体和小脑之间表现出异常的相互作用和功能连接,与纹状体形态计量学和尼古丁依赖有关。这些发现可以为重度吸烟者尼古丁依赖的神经相关性提供新的见解。
    Previous studies have found that the striatum and the cerebellum played important roles in nicotine dependence, respectively. In heavy smokers, however, the effect of resting-state functional connectivity of cerebellum-striatum circuits in nicotine dependence remained unknown. This study aimed to explore the role of the circuit between the striatum and the cerebellum in addiction in heavy smokers using structural and functional magnetic resonance imaging. The grey matter volume differences and the resting-state functional connectivity differences in cerebellum-striatum circuits were investigated between 23 heavy smokers and 23 healthy controls. The cigarette dependence in heavy smokers and healthy controls were evaluated by using Fagerström Test. Then, we applied mediation analysis to test whether the resting-state functional connectivity between the striatum and the cerebellum mediates the relationship between the striatum morphometry and the nicotine dependence in heavy smokers. Compared with healthy controls, the heavy smokers\' grey matter volumes decreased significantly in the cerebrum (bilateral), and increased significantly in the caudate (bilateral). Seed-based resting-state functional connectivity analysis showed significantly higher resting-state functional connectivity among the bilateral caudate, the left cerebellum, and the right middle temporal gyrus in heavy smokers. The cerebellum-striatum resting-state functional connectivity fully mediated the relationship between the striatum morphometry and the nicotine dependence in heavy smokers. Heavy smokers showed abnormal interactions and functional connectivity between the striatum and the cerebellum, which were associated with the striatum morphometry and nicotine dependence. Such findings could provide new insights into the neural correlates of nicotine dependence in heavy smokers.
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