Increased thalamic intrinsic oscillation amplitude in relapsing–remitting multiple sclerosis associated with the slowed cognitive processing

ObjectiveTo investigate the relationship between the amplitude of thalamic intrinsic neuronal activity, structural imaging indices, and the clinical neurological scales in relapsing–remitting multiple sclerosis (RRMS).MethodsTwenty-three patients with RRMS and 23 healthy controls were examined by resting-state fMRI (rs-fMRI) scan. Thalamic intrinsic oscillation amplitude was calculated by amplitude of low frequency fluctuation (ALFF) of rs-fMRI, as well as its correlations with clinical and structural imaging indices.ResultsCompared with the healthy controls, RRMS patients showed significantly increased ALFF values in bilateral thalami (P< .05, corrected). In the patient group, positive correlation was found between bilateral ALFF values and paced auditory serial addition test (left: P= .033; right: P= .016). Significant correlation was detected between the ALFF values and fractional anisotropy (FA) values in the left thalamus (r= 0.550, P= .007); only tendency increased correlation was detected between the ALFF values and FA values in the right thalamus (P= .114). No correlation was observed between bilateral thalamic ALFF values and disease duration, expanded disability status scale score, brain parenchymal fraction, or total white matter lesion loads (P> .05).ConclusionThe increased thalamic intrinsic oscillation amplitude as an ineffective reorganization was responded to microstructural damage in the RRMS patients, as well as it was associated with the slowed cognitive processing in relatively minimally disabled stage.     

肝性脑病患者基于静息态fMRI的全脑功能连接研究

目的：采用静息态功能磁共振成像研究肝性脑病患者全脑功能网络连接改变机制。方法：采集13例慢性肝硬化肝性脑病患者和17例健康志愿者的静息态血氧依赖水平功能磁共振成像（BOLD-fMRI）数据,采用自动化解剖标记（AAL）模板计算90个脑区的两两间功能连接情况。结果：肝性脑病患者有15条功能连接出现异常,其中12条功能连接显著下降（P〈0．01）,3条显著升高（P〈0．01）,且其中9条异常连接出现在皮层下区域与皮层区域之间,且改变的功能连接与神经心理学测试存在一定相关性。结论：肝性脑病患者的基底节一丘脑一皮层回路受损,功能连接的改变与肝性脑病患者认知功能的改变有关。     

Disrupted thalamic resting-state functional connectivity in patients with minimal hepatic encephalopathy

Background and purpose

Little is known about the role of thalamus in the pathophysiology of minimal hepatic encephalopathy (MHE). The purpose of this study was to investigate whether the thalamic functional connectivity was disrupted in cirrhotic patients with MHE by using resting-state functional magnetic resonance imaging (rs-fMRI).

Materials and Methods

Twenty seven MHE patients and twenty seven age- and gender- matched healthy controls participated in the rs-fMRI scans. The functional connectivity of 11 thalamic nuclei were characterized by using a standard seed-based whole-brain correlation method and compared between MHE patients and healthy controls. Pearson correlation analysis was performed between the thalamic functional connectivity and venous blood ammonia levels/neuropsychological tests scores of patients.

Results

The ventral anterior nucleus (VAN) and the ventral posterior medial nucleus (VPMN) in each side of thalamus showed abnormal functional connectivities in MHE. Compared with healthy controls, MHE patients demonstrated significant decreased functional connectivity between the right/left VAN and the bilateral putamen/pallidum, inferior frontal gyri, insula, supplementary motor area, right middle frontal gyrus, medial frontal gyrus. In addition, MHE patients showed significantly decreased functional connectivity with the right/left VPMN in the bilateral middle temporal gyri (MTG), temporal lobe, and right superior temporal gyrus. The venous blood ammonia levels of MHE patients negatively correlated with the functional connectivity between the VAN and the insula. Number connecting test scores showed negative correlation with the functional connectivity between the VAN and the insula, and between the VPMN and the MTG.

Conclusion

MHE patients had disrupted thalamic functional connectivity, which mainly located in the bilateral ventral anterior nuclei and ventral posterior medial nuclei. The decreased connectivity between thalamus and many cortices, and basal ganglia indicated reduced integrity of thalamic RSN in MHE.     

Thalamic metabolic alterations with cognitive dysfunction in idiopathic trigeminal neuralgia: a multivoxel spectroscopy study

Introduction

Although abnormalities in metabolite compositions in the thalamus are well described in patients with idiopathic trigeminal neuralgia (ITN), differences in distinct thalamic subregions have not been measured with proton magnetic resonance spectroscopy (¹H-MRS), and whether there are correlations between thalamic metabolites and cognitive function still remain unknown.

Methods

Multivoxel MRS was recorded to investigate the metabolic alterations in the thalamic subregions of patients with ITN. The regions of interest were localized in the anterior thalamus (A-Th), intralaminar portion of the thalamus (IL-Th), posterior lateral thalamus (PL-Th), posterior medial thalamus (PM-Th), and medial and lateral pulvinar of the thalamus (PuM-Th and PuL-Th). The N-acetylaspartate to creatine (NAA/Cr) and choline to creatine (Cho/Cr) ratios were measured in the ITN and control groups. Scores of the visual analogue scale (VAS) and the Montreal Cognitive Assessment (MoCA) were analyzed to correlate with the neuroradiological findings.

Results

The NAA/Cr ratio in the affected side of PM-Th and PL-Th in ITN patients was statistically lower than that in the corresponding regions of the thalamus in controls. The NAA/Cr ratio in the affected PM-Th was negatively associated with VAS and disease duration. Furthermore, decreases of NAA/Cr and Cho/Cr were detected in the affected side of IL-Th, and lower Cho/Cr was positively correlated with MoCA values in the ITN group.

Conclusions

Our result of low level of NAA/Cr in the affected PM-Th probably serves as a marker of the pain-rating index, and decreased Cho/Cr in IL-Th may be an indicator of cognitive disorder in patients with ITN.     

The neural correlates of falls: Alterations in large-scale resting-state networks in elderly fallers

IntroductionFalls are associated with numerous risk factors, such as motor and cognitive impairments. However, the neural correlates of falls are poorly understood.ObjectivesHere, we aimed to assess patterns of structural, and resting-state functional connectivity (FC) alterations related to falls in a group of older adults with a history of falls compared to non-fallers.MethodsFourteen elderly fallers (mean age = 78.1 ± 1.5 yrs, >2 falls previous six months), and 20 healthy controls (mean age = 69.6 ± 1.3 yrs) were examined. All participants underwent a 3T MRI scan obtaining 3D T1-weighted images, and eyes-open resting-state (rs)-fMRI. Voxel-based morphometry was conducted to detect grey matter differences between the groups. Independent component analysis was conducted based on rs-fMRI and number of attention-and-motor related functional networks was identified and compared between groups using an independent-sample T-test.ResultsNo differences were observed in grey matter between the groups after correcting for age and gender (p > 0.01, FWEc). Compared with non-fallers, the fallers had lower FC in cerebellar, frontal and parietal cortical nodes within the sensorimotor network (SMN), lateral motor network (M1), Cerebellar network (CBL), frontal-striatal network (FSN), executive control network (ECN), and dorsal attention network (DAN). Moreover, fallers had increased FC in the basal ganglia network (BGN), Left paracentral in M1 and SMN, and right hippocampus in DAN (p < 0.01, FWEc).ConclusionsAmong fallers, reduced connectivity was observed in areas that relate to integration of information, while increased connectivity was found in areas associated with motor and sensory information processing. Together, these results provide evidence to the complex multidimensionality of the neural underpinnings of falls. Furthermore, these findings may help emphasize the importance of interventions that target both motor and cognitive aspects.     

TIPS术后脑默认网络的静息态功能磁共振成像研究

目的：运用静息态功能磁共振成像（rs—fMRI）研究经颈静脉肝内门体分流术（TIPS）对肝硬化患者脑默认网络（DMN）的影响。方法：10例拟行TIPS治疗的肝硬化患者（患者组）和10例正常对照者（对照组）纳入本研究。10例正常对照者及10例患者术前、术后（平均8天）均行rs-fMRI。利用独立成分分析方法分离得到各受试者的默认网络脑区,采用单样本t检验对患者术前和对照组进行组内分析,观察各自的DMN空间分布模式;分别对患者TIPS术前与正常对照组、患者TIPS术后与术前的DMN功能连接进行组间比较,观察静息状态下脑默认网络的改变情况。结果：TIPS术前肝硬化患者和正常对照组均显示出典型的静息态脑默认网络空间分布模式。与正常对照组相比,TIPS术前肝硬化患者默认网络脑区功能连接既有降低也有增高,降低脑区包括左侧额中回背外侧、双侧顶下小叶及颞叶;增高的脑区主要位于双侧后扣带回、楔前叶及内侧前额叶。与TIPS术前相比,患者术后出现双侧楔前叶及角回功能连接增强,而后扣带回及内侧前额叶功能连接度减低。结论：静息状态下,TIPS术后早期肝硬化患者脑默认网络功能连接即出现改变,既有功能连接减低也有增强,提示TIPS对肝硬化患者脑默认网络既有功能损伤又有代偿机制。     

针刺治疗对腹泻型肠易激综合征病人rs-fMRI脑功能连接的影响

目的 探讨针刺治疗对腹泻型肠易激综合征（IBS-D）病人静息态功能MRI （rs-fMRI）的脑功能连接（FC）的影响。方法 前瞻性纳入性别、年龄及受教育程度相匹配的IBS-D病人24例及正常对照（NC）组23例。IBS-D病人接受“调神健脾”针刺法治疗6周（3次/周）,分别于治疗前、后采用严重程度评分（SSS）、生活质量量表（QOL）及汉密尔顿焦虑量表（HAMA）评价病情及针刺疗效。NC组仅于纳入当日行rs-fMRI检查,IBS-D病人分别于纳入当日和针刺治疗6周结束后48 h内行rs-fMRI检查。在自动解剖标记（AAL）脑区模板上选取双侧岛叶,扣带回（前、中、后部）,杏仁核及丘脑为种子点,构建其与全脑各脑区的FC。治疗前后量表评分比较采用配对t检验。NC组及治疗前后IBS-D病人的FC值比较采用单因素方差分析,组间两两比较采用事后检验。采用Pearson相关对IBS-D病人治疗前后的差异脑区FC值与临床量表评分进行分析。结果 IBS-D病人经针刺治疗后较治疗前的SSS、HAMA 评分下降（均P<0.05）,QOL评分升高（P<0.05）。与NC组相比,治疗前IBS-D病人的左侧岛叶-右侧颞中回、左侧中扣带回-右侧颞极颞中回脑区的FC增强（均P<0.05）;治疗后,上述FC均减弱（均P<0.05）。与NC组相比,治疗后右侧前扣带回-小脑蚓部3区的FC增强（P<0.05）,左侧杏仁核-左侧中央后回的FC减弱（P<0.05）;而治疗前上述FC差异无统计学意义（P>0.05）。治疗后IBS-D病人的右侧前扣带回-小脑蚓部3区间FC值（0.1±0.2）与HAMA评分（8.2±3.9）呈负相关（r=-0.451, P=0.027）,左侧杏仁核-左侧中央后回间FC值（-0.1±0.2）与HAMA评分（8.2±3.9）呈负相关（r=-0.456, P=0.025）。结论 针刺治疗可改变IBS-D病人与内脏疼痛、情绪调节相关脑区的FC,且与临床症状改善相关。     

The thalamus in cirrhotic patients with and without hepatic encephalopathy: A volumetric MRI study

Background & aims

The thalamus is a major relay and filter station in the central neural system. Some previous studies have suggested that the thalamus maybe implicated in the pathogenesis of hepatic encephalopathy. The aim of our study was to investigate changing thalamic volumes in cirrhotic patients with and without hepatic encephalopathy.

Methods

Neuropsychological tests and structural MR scanning were performed on 24 cirrhotic patients, 23 cirrhotic patients with minimal hepatic encephalopathy, 24 cirrhotic patients during their first episode of overt hepatic encephalopathy, and 33 healthy controls. Voxel-based morphometry analysis was performed to detect gray matter morphological changes. The thalamus and whole brain volume were extrapolated. A receiver operating characteristic curve analysis of thalamic volumes was used to discriminate patients with minimal hepatic encephalopathy from those with hepatic cirrhosis.

Results

Thalamic volume increased in a stepwise manner in patients with progressively worse stages of hepatic encephalopathy compared to healthy subjects. Additionally, a comparison of gray matter morphometry between patients with Child–Pugh grades A, B, or C and controls revealed a progression in thalamic volumes in parallel with the degree of liver failure. Moreover, thalamic volume was significantly correlated with the number connection test A time and digit-symbol test score in cirrhotic patients with minimal hepatic encephalopathy (r = 0.659, P = 0.001; r = −0.577, P = 0.004; respectively). The area under the receiver operating characteristic curve was 0.827 (P = 0.001).

Conclusions

A significantly increased thalamic volume may be provide an objective imaging measure for predicting seizures due to minimal hepatic encephalopathy in cirrhotic patients.     

Functional and structural changes in gray matter of parkinson's disease patients with mild cognitive impairment

Background and purposeCognitive impairment is a common non-motor complication of Parkinson’s disease (PD). To investigate cognitive-related changes of gray matter (GM) structure and function in PD using voxel-based morphometry (VBM) and resting state functional connectivity (RSFC).Materials and methodsResting state functional magnetic resonance imaging (rs-fMRI) and 3D-T1-weighted MRI scans were obtained from 21 PD patients with mild cognitive impairment (PD-MCI), 11 PD patients with normal cognitive function (PD-NC), and 21 healthy controls (HC). Functional connectivity (FC) was analyzed by defining the posterior cingulated cortex (PCC) as the seed region. VBM was performed to assess patterns of GM atrophy.ResultsIn PD-NC versus HC, results indicated decreased PCC-FC in the right temporal gyrus(TG) and increased PCC-FC in the left medial temporal lobe(MTL), bilateral precuneus(Pcu), and parieto-occipital junction(POJ), as well as GM atrophy in the bilateral prefrontal-striatal circuit(pFTSC), TG and Pcu. In PD-MCI versus PD-NC, decreased PCC-FC was found in the bilateral prefrontal cortex(PFC), left POJ, and right TG. In addition, PCC-FC of the bilateral Pcu and GM volume of the left MTL, bilateral TG, and PFC were positively associated with cognitive score.ConclusionsStructural and functional damage of the PFC and temporal lobe are associated with subtle cognitive decline in PD, while functional enhancement of the MTL and POJ is involved in normal cognitive function of PD. In addition, the combined application of rs-fMRI and VBM analysis might become an effective means to investigate cognitive impairment-related GM abnormalities in PD-MCI patients prior to development of dementia.     

Differences in dynamic and static functional connectivity between young and elderly healthy adults

Purpose

Brain connectivity is highly dynamic, but functional connectivity (FC) studies using resting-state functional magnetic resonance imaging (rs-fMRI) assume it to be static. This study assessed differences in dynamic FC between young healthy adults (YH) and elderly healthy adults (EH) compared to static FC.

Methods

Using rs-fMRI data from 12 YH and 31 EH, FC was assessed in six functional regions (subcortical, auditory [AUD], sensorimotor [SM], visuospatial [VS], cognitive control [CC], and default mode network [DMN]). Static FC was calculated as Fisher’s z-transformed correlation coefficient. The sliding time window correlation (window size 30 s, step size 3 s) was applied for dynamic FC, and the standard deviation across sliding windows was calculated. Differences in static and dynamic FC between EH and YH were calculated and compared by region.

Results

EH showed decreased static FC in the subcortical, CC, and DMN regions (FDR corrected p = 0.0013; 74 regions), with no regions showing static FC higher than that in YH. EH showed increased dynamic FC in the subcortical, CC, and DMN regions, whereas decreased dynamic FC in CC and DMN regions (p < 0.01). However, the regions showing differences between EH and YH did not overlap between static and dynamic FC.

Conclusion

Dynamic FC exhibited differences from static FC in EH and YH, mainly in regions involved in cognitive control and the DMN. Altered dynamic FC demonstrated both qualitatively and quantitatively distinct patterns of transient brain activity and needs to be studied as an imaging biomarker in the aging process.

     

肝移植术后认知与脑改变的多模态神经成像

肝性脑病是终末期肝硬化的重要并发症,导致病人出现一系列神经及认知功能改变。肝移植术后病人在肝功能恢复的同时其认知功能也可明显改善。MRI可以从脑代谢、结构及功能方面更进一步揭示肝硬化病人移植术后认知及脑改变情况。综述肝移植术后认知改变的研究现状以及最新的多模态MRI技术在术后脑改变中的应用,及其在揭示术后认知恢复及残存损害的神经机制中的价值。     

Brain regional homogeneity changes following transjugular intrahepatic portosystemic shunt in cirrhotic patients support cerebral adaptability theory—A resting-state functional MRI study

Purpose

The exact neuro-pathophysiological effect of transjugular intrahepatic portosystemic shunt (TIPS) on brain function remains unclear. The purpose of this study was to investigate the longitudinal brain activity changes in cirrhotic patients with TIPS insertion using resting-state functional MRI (fMRI) with regional homogeneity (ReHo) method.

Methods

Fifteen cirrhotic patients without overt hepatic encephalopathy (OHE) planned for TIPS procedure and 15 age- and gender-matched healthy controls were included in this study. Eleven of the 15 patients underwent repeated fMRI examinations at median 7-day following TIPS, 8 patients in median 3-month, and 7 patients in median 1-year follow-up duration, respectively. Regional homogeneity was calculated by the Kendall's coefficient of concordance (KCC) and compared between patients before TIPS and healthy controls with two-sample t test as well as pre-and post-TIPS patients with paired t test. Correlations between the pre- and post-TIPS changes of ReHo and the changes of venous blood ammonia level and number connection test type A (NCT-A)/digit symbol test (DST) scores were calculated by crossing subjects.

Results

Compared with healthy controls, 15 cirrhotic patients before TIPS procedure showed decreased ReHo in the bilateral frontal, parietal, temporal and occipital lobes and increased ReHo in the bilateral caudate. Compared with the pre-TIPS patients, 11 post-TIPS patients in the median 7-day follow-up examinations demonstrated decreased ReHo in the medial frontal gyrus (MFG), superior parietal gyrus (SPG), middle/superior temporal gyrus (M/STG), anterior cingulate cortex (ACC), caudate, and increased ReHo in the insula. Eight post-TIPS patients in the median 3-month follow-up examinations showed widespread decreased ReHo in the bilateral frontal and parietal lobes, ACC, caudate, and increased ReHo in the insula and precuneus/cuneus. In the median 1-year follow-up studies, seven post-TIPS patients displayed decreased ReHo in the bilateral frontal and parietal lobes, ACC, supplementary motor area (SMA), posterior cingulate cortex (PCC), and increased ReHo in the caudate and insula (P < 0.05, Alphasim corrected). The changes of ReHo values in bilateral IPL, MFG, caudate and SMA were correlated with changes of DST scores during the median 3-month follow-up (all P < 0.05).

Conclusion

The TIPS implantation had a persistent effect on brain function in cirrhotic patients including both predominant impairment and compensation mechanisms, with the most significant alterations in the median 3-month period after TIPS. The ReHo analysis may be potentially valuable for uncovering the mechanism of TIPS’ effects on brain function.     

Single photon emission computed tomography and statistical parametric mapping analysis in cirrhotic patients with and without minimal hepatic encephalopathy

OBJECTIVE: The early diagnosis and treatment of cognitive impairment in cirrhotic patients is needed to improve the patients' daily living. In this study, alterations of regional cerebral blood flow (rCBF) were evaluated in cirrhotic patients using statistical parametric mapping (SPM). The relationships between rCBF and neuropsychological test, severity of disease and biochemical data were also assessed. METHODS: 99mTc-ethyl cysteinate dimer single photon emission computed tomography was performed in 20 patients with non-alcoholic liver cirrhosis without overt hepatic encephalopathy (HE) and in 20 age-matched healthy subjects. Neuropsychological tests were performed in 16 patients; of these 7 had minimal HE. Regional CBF images were also analyzed in these groups using SPM. RESULTS: On SPM analysis, cirrhotic patients showed regions of significant hypoperfusion in the superior and middle frontal gyri, and inferior parietal lobules compared with the control group. These areas included parts of the premotor and parietal associated areas of the cortex. Among the cirrhotic patients, those with minimal HE had regions of significant hypoperfusion in the cingulate gyri bilaterally as compared with those without minimal HE. CONCLUSIONS: Abnormal function in the above regions may account for the relatively selective neuropsychological deficits in the cognitive status of patients with cirrhosis. These findings may be important in the identification and management of cirrhotic patients with minimal HE.     

Abnormal changes in functional connectivity between the amygdala and frontal regions are associated with depression in Alzheimer’s disease

Purpose

The aim of the present study was to investigate the functional connectivity (FC) of Alzheimer’s disease patients with depression (D-AD) based on an amygdalar seed using resting-state functional magnetic resonance imaging (rs-fMRI).

Methods

Twenty-one non-depressed AD (nD-AD) patients and 21 D-AD patients underwent rs-fMRI. The Hamilton Depression Rating Scale and Neuropsychiatric Inventory were used to evaluate the severity of depression. The amygdala was used as the seed for FC analysis. The FC differences between the two groups were evaluated by two-sample t tests, and the correlation of FC changes with depressive severity was analyzed by Pearson correlational analysis.

Results

Compared with the nD-AD patients, D-AD patients had increased FC values between the amygdala and orbitofrontal cortex and decreased FC values among the amygdala, medial prefrontal cortex, and inferior frontal gyrus.

Conclusion

These data suggest that abnormal amygdala-prefrontal FC may be an important characteristic of AD patients with depression.

     

肝硬化患者认知控制的fMRI研究

目的 利用功能磁共振成像(fMRI)技术探讨肝硬化患者认知控制功能的神经学机制. 资料与方法 搜集14例肝硬化患者和14名正常志愿者进行研究.采用改编的Stroop任务进行组块式设计fMRI,利用统计参数图(SPM99)软件进行图像分析.所有检查完毕后,对受试者进行行为学测试,记录测试的总反应时间以及错误数. 结果 患者组执行两试验的反应时间均长于正常对照组(P=0.001;P<0.001),执行颜色命名试验的错误数高于认字试验(P＝0.000),执行颜色命名试验时的错误数高于正常对照组(P＝0.001).肝硬化患者执行简单的认字任务时双侧前额叶及顶叶多个脑区激活增加.随着冲突强度增加,肝硬化患者扣带回、双侧前额叶、顶叶以及颞叶梭状回激活减少. 结论 肝硬化患者存在认知控制功能的障碍,而扣带回-前额叶-顶叶-颞叶梭状回网络的异常是肝硬化患者认知控制功能障碍的神经基础.     

Changes in cerebral blood flow after transjugular intrahepatic portosystemic shunt can help predict the development of hepatic encephalopathy: An arterial spin labeling MR study

Background and purpose

Cerebral blood flow (CBF) changes after transjugular intrahepatic portosystemic shunt (TIPS) are still unclear. Our aim is to assess the TIPS-induced CBF changes and their potential clinical significance using the arterial spin labeling (ASL) perfusion magnetic resonance imaging.

Materials and methods

Nine cirrhotic patients underwent ASL 1–8 days before and 4–7 days after TIPS. CBF was calculated at each voxel and mean CBF values were computed in the whole brain, gray matter and white matter. Changes of CBFs before and after TIPS were compared by paired t-test.

Results

Voxel-wise results showed CBF diffusely increased in patients after TIPS, but no region with significant decrease in CBF was found, nor was any significant mean CBF difference detected in the whole brain, gray matter and white matter. Six patients out of nine showed a global CBF increase of 9–39%; one patient presented a global CBF decrease of 6%; another two showed a global CBF decrease of 16% and 31% respectively. Follow-up studies showed that the two patients with greatly decreased global CBF suffered from multiple episodes of overt hepatic encephalopathy (OHE) after TIPS and one died of OHE.

Conclusions

CBF derived from noninvasive ASL MRI could be used as a useful biomarker to predict the development of OHE through consecutively tracking CBF changes in patients with inserted TIPS. Increased CBFs in many cortical regions could be common effects of the TIPS procedure, while decreased global CBF following TIPS might indicate the development of OHE.     

Response Evaluation Criteria in Solid Tumors (RECIST) Criteria Are Superior to European Association for Study of the Liver (EASL) Criteria at 1 Month Follow-up for Predicting Long-term Survival in Patients Treated with Transarterial Chemoembolization before Liver Transplantation for Hepatocellular Cancer

PurposeTo determine whether response to transarterial chemoembolization can predict survival in patients with hepatocellular carcinoma (HCC) who are candidates for orthotopic liver transplantation (LT) and if either European Association for Study of the Liver (EASL) criteria or Response Evaluation Criteria in Solid Tumors (RECIST) criteria are more accurate for this purpose.Materials and MethodsA retrospective review of all patients who underwent LT after transarterial chemoembolization between January 2005 and June 2011 was performed. Follow-up imaging with multiphasic computed tomography or magnetic resonance imaging was performed 1 month after transarterial chemoembolization and every 3 months thereafter until LT. Treatment response was evaluated at each imaging time point using RECIST criteria and EASL criteria. The relationship between survival and objective response (OR), time to response (TTR), time to progression (TTP), and time interval between transarterial chemoembolization and LT was assessed.ResultsA median of one transarterial chemoembolization procedure was performed before LT in 58 patients (52 men, 6 women; mean age, 57 y). OR was shown by 28 (48%) patients and 51 (88%) patients at 1 month by EASL criteria and RECIST criteria, respectively. OR at 1-month follow-up using RECIST criteria was associated with increased survival compared with patients with no response (NR) (P = .03). Using RECIST criteria, 5-year survival in the OR group was 66.7% versus 0% in the NR group (P = .015). There was no significant difference in survival in patients who showed OR at 1 month using EASL criteria. There was poor agreement between RECIST and EASL response assessments (κ = 0.23). There was no significant association between survival and TTR, TTP, or time interval between transarterial chemoembolization and LT.ConclusionsPatients with objective response to transarterial chemoembolization at 1 month using RECIST criteria showed improved survival over nonresponders. RECIST criteria demonstrated better accuracy compared with EASL criteria for predicting survival in patients after LT who had transarterial chemoembolization as a “bridge.”     

Disrupted Resting-State Functional Connectivity in Progressive Supranuclear Palsy

BACKGROUND AND PURPOSE:Studies on functional connectivity in progressive supranuclear palsy have been restricted to the thalamus and midbrain tegmentum. The present study aims to evaluate functional connectivity abnormalities of the subcortical structures in these patients. Functional connectivity will be correlated with motor and nonmotor symptoms of the disease.MATERIALS AND METHODS:Nineteen patients with progressive supranuclear palsy (mean age, 70.93 ± 5.19 years) and 12 age-matched healthy subjects (mean age, 69.17 ± 5.20 years) underwent multimodal MR imaging, including fMRI at rest, 3D T1-weighted imaging, and DTI. fMRI data were processed with fMRI of the Brain Software Library tools by using the dorsal midbrain tegmentum, thalamus, caudate nucleus, putamen, and pallidum as seed regions.RESULTS:Patients had lower functional connectivity than healthy subjects in all 5 resting-state networks, mainly involving the basal ganglia, thalamus, anterior cingulate, dorsolateral prefrontal and temporo-occipital cortices, supramarginal gyrus, supplementary motor area, and cerebellum. Compared with healthy subjects, patients also displayed subcortical atrophy and DTI abnormalities. Decreased thalamic functional connectivity correlated with clinical scores, as assessed by the Hoehn and Yahr Scale and by the bulbar and mentation subitems of the Progressive Supranuclear Palsy Rating Scale. Decreased pallidum functional connectivity correlated with lower Mini-Mental State Examination scores; decreased functional connectivity in the dorsal midbrain tegmentum network correlated with lower scores in the Frontal Assessment Battery.CONCLUSIONS:The present study demonstrates a widespread disruption of cortical-subcortical connectivity in progressive supranuclear palsy and provides further insight into the pathophysiologic mechanisms of motor and cognitive impairment in this condition.

Progressive supranuclear palsy (PSP) is one of the most common forms of atypical parkinsonism, characterized by early-onset postural instability, falls, and oculomotor abnormalities. Patients with PSP often have cognitive impairment, involving frontal executive functions and language, and behavioral symptoms, including apathy and social withdrawal or disinhibition.^1,2 The pathologic changes in PSP include neuronal degeneration and τ immune-reactive depositions in the basal ganglia, diencephalon, brain stem, and cerebellum, with limited involvement of the neocortex.³MR imaging has detected several structural changes in PSP, which mainly involve the midbrain, thalamus, basal ganglia, frontal cortex, and white matter bundles, reflecting the underlying neurodegenerative processes present in this condition.^4–7 However, the relationship between brain abnormalities and clinical manifestations is still unclear.The resting-state fMRI technique is a method used to investigate spontaneous neuronal activity at rest.⁸ Spontaneous neuronal activity is identified by slow fluctuations in the blood oxygen level–dependent signal and is represented by spatial maps of correlations of these blood oxygen level–dependent signal fluctuations within anatomically separate brain regions, also defined as maps of functional connectivity (FC).⁸ FC in PSP has previously been explored in 2 studies with a limited focus on the thalamus⁹ and dorsal midbrain tegmentum (dMT) regions.¹⁰ Both studies reported functional disconnection between each of these structures and some cortical, subcortical, and cerebellar sites.^9,10 It is unknown whether FC abnormalities also affect other key subcortical areas in PSP.³ Owing to the widespread degeneration of subcortical structures in PSP,³ the FC of the caudate nucleus, putamen, and pallidum may also be affected in this condition. Due to the basal ganglia involvement in motor and cognitive functions, through the parallel interconnections with the frontal cortex,^11,12 understanding FC abnormalities of the caudate nucleus, putamen, and pallidum in PSP would provide further information on the pathophysiologic mechanisms of the disease. To achieve this goal, we evaluated the FC from the caudate, putamen, and pallidum nuclei, in addition to the thalamus and dMT. The ultimate aim of this article was to investigate possible correlations between cortical-subcortical network disruption and clinical scores of disease severity.     

Changes in thalamus connectivity in mild cognitive impairment: evidence from resting state fMRI

Purpose

The subcortical region such as thalamus was believed to have close relationship with many cerebral cortexes which made it especially interesting in the study of functional connectivity. Here, we used resting state functional MRI (fMRI) to examine changes in thalamus connectivity in mild cognitive impairment (MCI), which presented a neuro-disconnection syndrome.

Materials and methods

Data from 14 patients and 14 healthy age-matched controls were analyzed. Thalamus connectivity was investigated by examination of the correlation between low frequency fMRI signal fluctuations in the thalamus and those in all other brain regions.

Results

We found that functional connectivity between the left thalamus and a set of regions was decreased in MCI; these regions are: bilateral cuneus, middle occipital gyrus (MOG), superior frontal gyrus (SFG), medial prefrontal cortex (MPFC), precuneus, inferior frontal gyrus (IFG) and precentral gyrus (PreCG). There are also some regions showed reduced connectivity to right thalamus; these regions are bilateral cuneus, MOG, fusiform gyrus (FG), MPFC, paracentral lobe (PCL), precuneus, superior parietal lobe (SPL) and IFG. We also found increased functional connectivity between the left thalamus and the right thalamus in MCI.

Conclusion

The decreased connectivity between the thalamus and the other brain regions might indicate reduced integrity of thalamus-related cortical networks in MCI. Furthermore, the increased connectivity between the left and right thalamus suggest compensation for the loss of cognitive function. Briefly, impairment and compensation of thalamus connectivity coexist in the MCI patients.     

MR and cerebrospinal fluid enzymes as sensitive indicators of subclinical cerebral injury after open-heart valve replacement surgery.

PURPOSETo evaluate MR imaging and lumbar cerebrospinal fluid enzymes as potential sensitive indicators of cerebral injury after open-heart valve replacement surgery.METHODSThirty-four patients with cardiac valvular disease were prospectively entered into this study and then underwent valve replacement or repair under cardiopulmonary bypass using a membrane oxygenator. In 26 patients, MR head images were obtained 12 to 24 hours before surgery; repeat MR images were obtained between 1 and 2 weeks after surgery. In 18 patients, lumbar puncture cerebrospinal fluid was analyzed 24 to 48 hours after surgery; the analyses included measurement of lactic dehydrogenase, creatine phosphokinase, adenylate kinase, and neuron-specific enolase.RESULTSAfter surgery, MR imaging showed new ischemic lesions in 15 (58%) of 26 patients: 7 with deep white matter hyperintense lesions; 5 with brain stem, caudate, cerebellar, or thalamic/basal ganglia infarcts; 1 with intraparenchymal hemorrhage; 1 with a subdural hematoma and cortical infarct; and 1 with a corpus callosum lesion consistent with calcium or air. These new ischemic lesions seen on MR images were associated with a focal neurologic deficit in only 4 (27%) of the 15 patients. Neuron-specific enolase and lactic dehydrogenase were abnormally elevated after surgery in 5 (28%) of 18 patients. Adenylate kinase and creatine phosphokinase (brain isozymes) were elevated in one (67%) of the patients. Two (40%) of the five patients with abnormally high neuron-specific enolase or lactic dehydrogenase after surgery also showed a new focal neurologic deficit.CONCLUSIONSMR imaging is a sensitive measure of subclinical cerebral ischemia after cardiac valve replacement under cardiopulmonary bypass. Cerebrospinal fluid neuron-specific enolase and lactic dehydrogenase are less sensitive than MR imaging for detecting subclinical cerebral ischemia, but these values were elevated after surgery more frequently than was adenylate kinase in our patients.