Brain Microstructural Abnormalities in Patients With Cirrhosis Without Overt Hepatic Encephalopathy: A Voxel-Based Diffusion Kurtosis Imaging Study. AJR Am J Roentgenol. 2017;209:1128-1135. [PMID: 28813200 DOI: 10.2214/ajr.17.17827]

Functional connectivity disruption of insular subregions in the cirrhotic patients with minimal hepatic encephalopathy

We investigated abnormal functional connectivity (FC) patterns of insular subregions in patients with minimal hepatic encephalopathy (MHE) and examined their relationships with cognitive dysfunction using resting-state functional magnetic resonance imaging (fMRI). We collected resting-state fMRI data in 54 patients with cirrhosis [20 with MHE and 34 without MHE (NHE)] and 25 healthy controls. After defining six subregions of insula, we mapped whole-brain FC of the insular subregions and identified FC differences through three groups. FC of the insular subregions was correlated against clinical parameters (including venous blood ammonia level, Child-Pugh score, and cognitive score). The discrimination performance between the MHE and NHE groups was evaluated by performing a classification analysis using the FC index. Across three groups, the observed FC differences involved four insular subregions, including the left-ventral anterior insula, left-dorsal anterior insula, right-dorsal anterior insula, and left-posterior insula (P < 0.05 with false discovery rate correction). Moreover, the FC of these four insular subregions progressively attenuated from NHE to MHE. In addition, hypoconnectivity of insular subregions was correlated with the poor neuropsychological performance and the evaluated blood ammonia levels in patients (P < 0.05 with Bonferroni correction). The FC of insular subregions yielded moderate discriminative value between the MHE and NHE groups (AUC = 0.696-0.809). FC disruption of insular subregions is related to worse cognitive performance in MHE. This study extended our understanding about the neurophysiology of MHE and may assist for its diagnosis.

Metabolic alterations in the right anterior insula among patients with cirrhosis without overt hepatic encephalopathy: a magnetic resonance spectroscopy study

Purpose

We investigated metabolic alterations in the right anterior insula (rAI) in cirrhotic patients and determined its association with patients' cognitive dysfunction.

Methods

In this study, 31 healthy controls (HCs) and 32 cirrhotic patients without overt hepatic encephalopathy participated. Both blood ammonia level and Child-Pugh score were measured. The psychometric hepatic encephalopathy score (PHES) was used to evaluate cognitive function. 1H-magnetic resonance spectroscopy (MRS) data located in the rAI were recorded on a commercially available 3T magnetic resonance imaging scanner. The ratios of metabolites were measured, including N-acetylaspartate (NAA)/total creatine (tCr), glutamate plus glutamine (Glx)/tCr, myo-inositol (mI)/tCr, and total choline (tCho)/tCr. We adopted the non-parametric Mann-Whitney U-test for intergroup comparison of metabolic ratios. To determine the association between metabolite concentration and clinical parameters, we performed Spearman correlation analyses.

Results

Patients with cirrhosis performed worse on PHES in comparison with HCs (P < 0.001). Patients with cirrhosis had significantly decreased mI/tCr (0.87 ± 0.07 vs. 0.74 ± 0.19, P = 0.025) and increased Glx/tCr (1.79 ± 0.17 vs. 2.07 ± 0.29, P < 0.001) in the rAI. We did not observe any significant between-group differences in tCho/tCr and NAA/tCr. The blood ammonia level was correlated with Glx/tCr (r = 0.405, P = 0.022) and mI/tCr (r = -0.398, P = 0.024) of the rAI. In addition, PHES was negatively correlated with Glx/tCr of the rAI (r = -0.379, P = 0.033).

Conclusion

Metabolic disturbance of the rAI, which is associated with ammonia intoxication, might account for the neural substrate of cirrhosis-related cognitive dysfunction to some extent.

Identifying Minimal Hepatic Encephalopathy: A New Perspective from Magnetic Resonance Imaging

Type C hepatic encephalopathy (HE) is a condition characterized by brain dysfunction caused by liver insufficiency and/or portal-systemic blood shunting, which manifests as a broad spectrum of neurological or psychiatric abnormalities, ranging from minimal HE (MHE), detectable only by neuropsychological or neurophysiological assessment, to coma. Though MHE is the subclinical phase of HE, it is highly prevalent in cirrhotic patients and strongly associated with poor quality of life, high risk of overt HE, and mortality. It is, therefore, critical to identify MHE at the earliest and timely intervene, thereby minimizing the subsequent complications and costs. However, proper and sensitive diagnosis of MHE is hampered by its unnoticeable symptoms and the absence of standard diagnostic criteria. A variety of neuropsychological or neurophysiological tests have been performed to diagnose MHE. However, these tests are nonspecific and susceptible to multiple factors (eg, aging, education), thereby limiting their application in clinical practice. Thus, developing an objective, effective, and noninvasive method is imperative to help detect MHE. Magnetic resonance imaging (MRI), a noninvasive technique which can produce many objective biomarkers by different imaging sequences (eg, Magnetic resonance spectroscopy, DWI, rs-MRI, and arterial spin labeling), has recently shown the ability to screen MHE from NHE (non-HE) patients accurately. As advanced MRI techniques continue to emerge, more minor changes in the brain could be captured, providing new means for early diagnosis and quantitative assessment of MHE. In addition, the advancement of artificial intelligence in medical imaging also presents the potential to mine more effective diagnostic biomarkers and further improves the predictive efficiency of MHE. Taken together, advanced MRI techniques may provide a new perspective for us to identify MHE in the future. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.

Enhanced Activation of the S1PR2-IL-1β-Src-BDNF-TrkB Pathway Mediates Neuroinflammation in the Hippocampus and Cognitive Impairment in Hyperammonemic Rats

Hyperammonemia contributes to hepatic encephalopathy. In hyperammonemic rats, cognitive function is impaired by altered glutamatergic neurotransmission induced by neuroinflammation. The underlying mechanisms remain unclear. Enhanced sphingosine-1-phosphate receptor 2 (S1PR2) activation in the cerebellum of hyperammonemic rats contributes to neuroinflammation. in In hyperammonemic rats, we assessed if blocking S1PR2 reduced hippocampal neuroinflammation and reversed cognitive impairment and if the signaling pathways were involved. S1PR2 was blocked with intracerebral JTE-013, and cognitive function was evaluated. The signaling pathways inducing neuroinflammation and altered glutamate receptors were analyzed in hippocampal slices. JTE-013 improved cognitive function in the hyperammonemic rats, and hyperammonemia increased S1P. This increased IL-1β, which enhanced Src activity, increased CCL2, activated microglia and increased the membrane expression of the NMDA receptor subunit GLUN2B. This increased p38-MAPK activity, which altered the membrane expression of AMPA receptor subunits and increased BDNF, which activated the TrkB → PI3K → Akt → CREB pathway, inducing sustained neuroinflammation. This report unveils key pathways involved in the induction and maintenance of neuroinflammation in the hippocampus of hyperammonemic rats and supports S1PR2 as a therapeutic target for cognitive impairment.

White matter microstructural disruption in minimal hepatic encephalopathy: a neurite orientation dispersion and density imaging (NODDI) study

PURPOSE

To evaluate the ability of neurite orientation dispersion and density imaging (NODDI) for detecting white matter (WM) microstructural abnormalities in minimal hepatic encephalopathy (MHE).

METHODS

Diffusion-weighted images, enabling the estimation of NODDI and diffusion tensor imaging (DTI) parameters, were acquired from 20 healthy controls (HC), 22 cirrhotic patients without MHE (NHE), and 15 cirrhotic patients with MHE. Tract-based spatial statistics were used to determine differences in DTI (including fractional anisotropy [FA] and mean/axial/radial diffusivity [MD/AD/RD]) and NODDI parameters (including neurite density index [NDI], orientation dispersion index [ODI], and isotropic volume fraction [ISO]). Voxel-wise analyses of correlations between diffusion parameters and neurocognitive performance determined by Psychometric Hepatic Encephalopathy Score (PHES) were completed.

RESULTS

MHE patients had extensive NDI reduction and rare ODI reduction, primarily involving the genu and body of corpus callosum and the bilateral frontal lobe, corona radiata, external capsule, anterior limb of internal capsule, temporal lobe, posterior thalamic radiation, and brainstem. The extent of NDI and ODI reduction expanded from NHE to MHE. In both MHE and NHE groups, the extent of NDI change was quite larger than that of FA change. No significant intergroup difference in ISO/MD/AD/RD was observed. Tissue specificity afforded by NODDI revealed the underpinning of FA reduction in MHE. The NDI in left frontal lobe was significantly correlated with PHES.

CONCLUSION

MHE is characterized by diffuse WM microstructural impairment (especially neurite density reduction). NODDI can improve the detection of WM microstructural impairments in MHE and provides more precise information about MHE-related pathology than DTI.

Causal effects of nonalcoholic fatty liver disease on cerebral cortical structure: a Mendelian randomization analysis

Background

Previous studies have highlighted changes in the cerebral cortical structure and cognitive function among nonalcoholic fatty liver disease (NAFLD) patients. However, the impact of NAFLD on cerebral cortical structure and specific affected brain regions remains unclear. Therefore, we aimed to explore the potential causal relationship between NAFLD and cerebral cortical structure.

Methods

We conducted a Mendelian randomization (MR) study using genetic predictors of alanine aminotransferase (ALT), NAFLD, and percent liver fat (PLF) and combined them with genome-wide association study (GWAS) summary statistics from the ENIGMA Consortium. Several methods were used to assess the effect of NAFLD on full cortex and specific brain regions, along with sensitivity analyses.

Results

At the global level, PLF nominally decreased SA of full cortex; at the functional level, ALT presented a nominal association with reduced SA of parahippocampal gyrus, TH of pars opercularis, TH of pars orbitalis, and TH of pericalcarine cortex. Besides, NAFLD presented a nominal association with reduced SA of parahippocampal gyrus, TH of pars opercularis, TH of pars triangularis and TH of pericalcarine cortex, but increased TH of entorhinal cortex, lateral orbitofrontal cortex and temporal pole. Furthermore, PLF presented a nominal association with reduced SA of parahippocampal gyrus, TH of pars opercularis, TH of cuneus and lingual gyrus, but increased TH of entorhinal cortex.

Conclusion

NAFLD is suggestively associated with atrophy in specific functional regions of the human brain.

Aberrant stability of brain functional architecture in cirrhotic patients with minimal hepatic encephalopathy

To investigate the stability changes of brain functional architecture and the relationship between stability change and cognitive impairment in cirrhotic patients. Fifty-one cirrhotic patients (21 with minimal hepatic encephalopathy (MHE) and 30 without MHE (NHE)) and 29 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging and neurocognitive assessment using the Psychometric Hepatic Encephalopathy Score (PHES). Voxel-wise functional connectivity density (FCD) was calculated as the sum of connectivity strength between one voxel and others within the entire brain. The sliding window correlation approach was subsequently utilized to calculate the FCD dynamics over time. Functional stability (FS) is measured as the concordance of dynamic FCD. From HCs to the NHE and MHE groups, a stepwise reduction of FS was found in the right supramarginal gyrus (RSMG), right middle cingulate cortex, left superior frontal gyrus, and bilateral posterior cingulate cortex (BPCC), whereas a progressive increment of FS was observed in the left middle occipital gyrus (LMOG) and right temporal pole (RTP). The mean FS values in RSMG/LMOG/RTP (r = 0.470 and P = 0.001; r = -0.458 and P = 0.001; and r = -0.384 and P = 0.005, respectively) showed a correlation with PHES in cirrhotic patients. The FS index in RSMG/LMOG/BPCC/RTP showed moderate discrimination potential between the NHE and MHE groups. Changes in FS may be linked to neuropathological bias of cognitive impairment in cirrhotic patients and could serve as potential biomarkers for MHE diagnosis and monitoring the progression of hepatic encephalopathy.

Brain Gray Matter Alterations in Hepatic Encephalopathy: A Voxel-Based Meta-Analysis of Whole-Brain Studies

Background

Previous studies on voxel-based morphometry (VBM) have found that there were gray matter alterations in patients with hepatic encephalopathy (HE). However, the reported results were inconsistent and lack a quantitative review. Therefore, this study aims for a quantitative meta-analysis of VBM analysis on patients with HE.

Methods

The studies in our meta-analysis were collected from Pubmed, Web of Science, and Embase, which were published from January 1947 to October 2021. The seed-based d mapping (SDM) method was applied to quantitatively estimate the regional gray matter abnormalities in patients with HE. A meta-regression analysis was applied to evaluate the relationship between plasma ammonia and gray matter alteration.

Results

There were nine studies, with sixteen datasets consisting of 333 participants with HE and 429 healthy controls. The pooled and subgroup meta-analyses showed an increase in gray matter volume (GMV) in the bilateral thalamus and the calcarine fissure but a decrease in the GMV in the bilateral insula, the basal ganglia, the anterior cingulate gyrus, and the cerebellum. The meta-regression showed that plasma ammonia was positively associated with the GMV in the left thalamus but was negatively associated with the GMV in the cerebellum and the bilateral striatum.

Conclusion

Gray matter volume in patients with HE largely varied and could be affected by plasma ammonia. The findings of this study could help us to better understand the pathophysiology of cognitive dysfunction in patients with HE.

Whole brain atlas-based diffusion kurtosis imaging parameters for evaluation of minimal hepatic encephalopathy

BACKGROUND AND PURPOSES

Minimal hepatic encephalopathy (MHE) has no recognizable clinical symptoms, but patients have cognitive and psychomotor deficits. Hyperammonemia along with neuroinflammation lead to microstructural changes in cerebral parenchyma. Changes at conventional imaging are detected usually at the overt clinical stage, but microstructural alterations by advanced magnetic resonance imaging techniques can be detected at an early stage.

MATERIALS AND METHODS

Whole brain diffusion kurtosis imaging (DKI) data acquired at 3T was analyzed to investigate microstructural parenchymal changes in 15 patients with MHE and compared with 15 age- and sex-matched controls. DKI parametric maps, namely kurtosis fractional anisotropy (kFA), mean kurtosis (MK), axial kurtosis (AK) and radial kurtosis (RK), were evaluated at 64 white matter (WM) and gray matter (GM) regions of interest (ROIs) in the whole brain and correlated with the psychometric hepatic encephalopathy score (PHES).

RESULTS

The MHE group showed a decrease in kFA and AK across the whole brain, whereas MK and RK decreased in WM ROIs but increased in several cortical and deep GM ROIs. These alterations were consistent with brain regions involved in cognitive function. Significant moderate to strong correlations (-0.52 to -0.66; 0.56) between RK, MK and kFA kurtosis metrics and PHES were observed.

CONCLUSION

DKI parameters show extensive microstructural brain abnormalities in MHE with minor correlation between the severity of tissue damage and psychometric scores.

Thalamic Structural Connectivity Abnormalities in Minimal Hepatic Encephalopathy

Background and Aims: Numerous studies have demonstrated thalamus-related structural, functional, and metabolic abnormalities in minimal hepatic encephalopathy (MHE). We conducted the first study to investigate thalamic structural connectivity alterations in MHE.

Radiomics-based classification models for HBV-related cirrhotic patients with covert hepatic encephalopathy

INTRODUCTION

The significant abnormalities of precuneus (PC), which are associated with brain dysfunction, have been identified in cirrhotic patients with covert hepatic encephalopathy (CHE). The present study aimed to apply radiomics analysis to identify the significant radiomic features in PC and their subregions, combine with clinical risk factors, then build and evaluate the classification models for CHE diagnosis.

METHODS

106 HBV-related cirrhotic patients (54 had current CHE and 52 had non-CHE) underwent the three-dimensional T1-weighted imaging. For each participant, PC and their subregions were segmented and extracted a large number of radiomic features and then identified the features with significant discriminative power as the radiomics signature. The logistic regression analysis was employed to develop and evaluate the classification models, which are constructed using the radiomics signature and clinical risk factors.

RESULTS

The classification model (R-C model) achieved best diagnostic performance, which incorporated radiomics signature (4 radiomic features from right PC), venous blood ammonia, and the Child-Pugh stage. And the area under the receiver operating characteristic curve values (AUC), sensitivity, specificity, and accuracy values were 0.926, 1.000, 0.765, and 0.848, in the testing set. Application of the radiomics nomogram in the testing set still showed a good predictive accuracy.

CONCLUSIONS

This study presented the radiomic features of the right PC, as a potential image marker of CHE. The radiomics nomogram that incorporates the radiomics signature and clinical risk factors may facilitate the individualized prediction of CHE.

The Role of Intestinal Bacteria and Gut-Brain Axis in Hepatic Encephalopathy

Hepatic encephalopathy (HE) is a neurological disorder that occurs in patients with liver insufficiency. However, its pathogenesis has not been fully elucidated. Pharmacotherapy is the main therapeutic option for HE. It targets the pathogenesis of HE by reducing ammonia levels, improving neurotransmitter signal transduction, and modulating intestinal microbiota. Compared to healthy individuals, the intestinal microbiota of patients with liver disease is significantly different and is associated with the occurrence of HE. Moreover, intestinal microbiota is closely associated with multiple links in the pathogenesis of HE, including the theory of ammonia intoxication, bile acid circulation, GABA-ergic tone hypothesis, and neuroinflammation, which contribute to cognitive and motor disorders in patients. Restoring the homeostasis of intestinal bacteria or providing specific probiotics has significant effects on neurological disorders in HE. Therefore, this review aims at elucidating the potential microbial mechanisms and metabolic effects in the progression of HE through the gut-brain axis and its potential role as a therapeutic target in HE.

Characterization of brain microstructural abnormalities in cirrhotic patients without overt hepatic encephalopathy using diffusion kurtosis imaging

Cirrhosis is a major public health concern. However, little is known about the neurobiological mechanisms underlying brain microstructure alterations in cirrhotic patients. The purpose of this prospective study was to investigate brain microstructural alterations in cirrhosis with or without minimal hepatic encephalopathy (MHE) and their relationship with patients’ neurocognitive performance and disease duration using voxel-based analysis of diffusion kurtosis imaging (DKI). DKI data were acquired from 30 cirrhotic patients with MHE, 31 patients without MHE (NMHE) and 59 healthy controls. All DKI-derived parametric maps were compared across the three groups to investigate their group differences. Correlation analyses were further performed to assess relationships between altered imaging parameters and clinical data. Voxel-based analysis of DKI data results showed that MHE/NMHE patients had increased radial diffusivity, axial diffusivity (AD) and mean diffusivity in addition to decreased axial kurtosis (AK) and fractional anisotropy of kurtosis in several regions. Compared to controls, these regions were primarily the cingulum, temporal and frontal cortices. The DKI metrics (i.e., AK and AD) were correlated with clinical variables in the two patient groups. In conclusion, DKI is useful for detecting brain microstructural abnormalities in MHE and NMHE patients. Abnormal DKI parameters suggest alterations in brain microstructural complexity in cirrhotic patients, which may contribute to the neurobiological basis of neurocognitive impairment. These results may provide additional information on the pathophysiology of cirrhosis.

Reduced Cortical Complexity in Cirrhotic Patients with Minimal Hepatic Encephalopathy

Purpose

Gray matter volume loss, regional cortical thinning, and local gyrification index alteration have been documented in minimal hepatic encephalopathy (MHE). Fractal dimension (FD), another morphological parameter, has been widely used to describe structural complexity alterations in neurological or psychiatric disease. Here, we conducted the first study to investigate FD alterations in MHE.

Methods and Materials

We performed high-resolution structural magnetic resonance imaging on cirrhotic patients with MHE (n = 20) and healthy controls (n = 21). We evaluated their cognitive performance using the psychometric hepatic encephalopathy score (PHES). The regional FD value was calculated by Computational Anatomy Toolbox (CAT12) and compared between groups. We further estimated the association between patients' cognitive performance and FD values.

Results

MHE patients presented significantly decreased FD values in the left precuneus, left supramarginal gyrus, right caudal anterior cingulate cortex, right isthmus cingulate cortex, right insula, bilateral pericalcarine cortex, and bilateral paracentral cortex compared to normal controls. In addition, the FD values in the right isthmus cingulate cortex and right insula were shown to be positively correlated with patients' cognitive performance.

Conclusion

Aberrant cortical complexity is an additional characteristic of MHE, and FD analysis may provide novel insight into the neurobiological basis of cognitive dysfunction in MHE.

Hippocampal atrophy and functional connectivity disruption in cirrhotic patients with minimal hepatic encephalopathy

The hippocampus is a crucial pathological node for minimal hepatic encephalopathy (MHE) and it is associated with various cognitive impairments. Investigations on alterations involving hippocampal morphology and functional connectivity (FC) in MHE are limited. This study aimed to simultaneously evaluate hippocampal volume and FC alterations and their association with cognitive decline in MHE. Twenty-two cirrhotic patients with MHE, 31 cirrhotic patients without MHE (NHE), and 43 healthy controls underwent high-resolution T1-weighted imaging, resting-state functional magnetic resonance imaging, and cognition assessment based on Psychometric Hepatic Encephalopathy Score (PHES). The structural images were preprocessed using a voxel-based morphometry method, during which hippocampal volume was measured. The hippocampal connectivity network was identified using seed-based correlation analysis. Hippocampal volume and FC strength were compared across the three groups and correlated against the PHES results of the cirrhotic patients. Compared to the controls, MHE patients exhibited a significantly lower bilateral hippocampal volume. A slight decrease in hippocampal volume was obtained from NHE to MHE, but it did not reach statistically significance. In addition, the average FC strength of the bilateral hippocampal connectivity network was significantly lower in the MHE patients. In particular, the MHE patients showed a decrease in FC involving the left hippocampus to bilateral posterior cingulate gyrus and left angular gyrus. The MHE patients also showed FC reduction between the right hippocampus and bilateral medial frontal cortex. A progressive reduction in hippocampal FC from NHE to MHE was also observed. The bilateral hippocampal FC strength (but not hippocampal volume) was positively correlated with the PHES results of the cirrhotic patients. Our assessment of MHE patients revealed decreased hippocampal volume, which suggests regional atrophy, and reduced hippocampal connectivity with regions that are primarily involved in the default-mode network, thereby suggesting a functional disconnection syndrome. These alterations reveal the mechanisms underlying cognitive deterioration with disease progression.

Decreased Mean Kurtosis in the Putamen is a Diagnostic Feature of Minimal Hepatic Encephalopathy in Patients with Cirrhosis

Objective To prevent the development of overt hepatic encephalopathy, the early intervention for minimal hepatic encephalopathy (MHE) based on an accurate diagnosis is essential. This study investigated whether or not magnetic resonance diffusion kurtosis imaging (DKI) and diffusion tensor imaging (DTI) could detect brain microstructure abnormalities in MHE. The aim was to confirm whether or not brain microstructure abnormalities detected by magnetic resonance (MR) imaging could be used for the diagnosis of MHE. Methods Thirty-two subjects were prospectively examined with a 3-T MR scanner. Tract-based spatial statistics and region of interest analyses of diffusion imaging were performed to compare the mean kurtosis (MK), fractional anisotropy (FA), and mean diffusivity (MD) values between patients with and without minimal hepatic encephalopathy. The diagnostic performance for the detection of MHE was assessed with a receiver operating characteristic analysis. Results Ten subjects were diagnosed with MHE by neuropsychological testing. After the exclusion of unsuitable subjects, we analyzed 9 subjects with MHE and 14 without MHE. The patients with MHE had a reduced MK in the widespread white matter. We also found significant decreases in the MK in the caudate nucleus, putamen, globus pallidus, and/or thalamus in the subjects with MHE. The MK in the putamen showed the best diagnostic performance for differentiating the subjects with MHE from those without MHE (cut-off value, 0.74; sensitivity, 0.89; specificity, 0.86). Conclusion DKI detects changes in the cerebral white matter and basal ganglia regions of patients with MHE more sensitively than DTI. The MK values in the putamen can be a useful marker for diagnosing MHE from cirrhotic patients without MHE.

Microstructural brain abnormalities correlate with neurocognitive dysfunction in minimal hepatic encephalopathy: a diffusion kurtosis imaging study

PURPOSE

To investigate the diffusion kurtosis imaging (DKI) in early minimal hepatic encephalopathy (MHE) diagnosis and evaluate the correlations between changes in DKI metrics and cognitive performance.

METHODS

We enrolled 116 cirrhosis patients, divided into non-HE (n = 61) and MHE (n = 55), and 46 normal controls (NCs). All patients underwent cognitive testing before magnetic resonance imaging. DKI metrics were calculated through whole-brain voxel-based analysis (VBA) and differences between the groups were assessed. Pearson correlation between the DKI metrics and cognitive performance was analysed. The receiver operating characteristic (ROC) curve was used to analyse the diagnostic efficiency of DKI metrics for MHE.

RESULTS

MHE patients had significantly altered DKI metrics in a wide range of regions; lower fractional anisotropy (FA) and higher mean diffusivity (MD) are mainly located in the corpus callosum, left temporal white matter (WM), and right medial frontal WM. Furthermore, significantly altered kurtosis metrics included lower mean kurtosis (MK) in the corpus callosum and left thalamus, lower radial kurtosis (RK) in the corpus callosum, and lower axial kurtosis (AK) in the right anterior thalamic radiation. Alterations in axial diffusivity (AD), radial diffusivity (RD), and MD were closely correlated with cognitive scores. The ROC curves indicated AD in the forceps minor had the highest predictive performance for MHE in the cirrhosis patients (area under curve = 0.801, sensitivity = 77.05%, specificity = 74.55%).

CONCLUSIONS

Altered DKI metrics indicate brain microstructure abnormalities in MHE patients, some of which may be used as neuroimaging markers for early MHE diagnosis.

Targeted puncture of left branch of intrahepatic portal vein in transjugular intrahepatic portosystemic shunt to reduce hepatic encephalopathy

BACKGROUND

Transjugular intrahepatic portosystemic shunt (TIPS) is currently used for the treatment of complications of portal hypertension. The incidence of hepatic encephalopathy (HE) remains a problem in TIPS placement. It has been reported that the right branch mainly receives superior mesenteric venous blood while the left branch mainly receives blood from the splenic vein. We hypothesized that targeted puncture of the left portal vein would divert the non-nutritive blood from the splenic vein into the TIPS shunt; therefore, targeted puncture of the left branch of the intrahepatic portal vein during TIPS may reduce the risk of HE.

AIM

To evaluate the influence of targeted puncture of left branch of portal vein in TIPS on HE.

METHODS

A retrospective analysis of 1244 patients with portal-hypertension-related complications of refractory ascites or variceal bleeding who underwent TIPS from January 2000 to January 2013 was performed. Patients were divided into group A (targeting left branch of portal vein, n = 937) and group B (targeting right branch of portal vein, n = 307). TIPS-related HE and clinical outcomes were analyzed.

RESULTS

The symptoms of ascites and variceal bleeding disappeared within a short time. By the endpoint of follow-up, recurrent bleeding and ascites did not differ significantly between groups A and B (P = 0.278, P = 0.561, respectively). Incidence of HE differed significantly between groups A and B at 1 mo (14.94% vs 36.80%, χ² = 4.839, P = 0.028), 3 mo (12.48% vs 34.20%, χ² = 5.054, P = 0.025), 6 mo (10.03% vs 32.24%, χ² = 6.560, P = 0.010), 9 mo (9.17% vs 31.27%, χ² = 5.357, P = 0.021), and 12 mo (8.21% vs 28.01, χ² = 3.848, P = 0.051). There were no significant differences between groups A and B at 3 years (6.61% vs 7.16%, χ² = 1.204, P = 0.272) and 5 years (5.01% vs 6.18%, χ² = 0.072, P = 0.562). The total survival rate did not differ between groups A and B (χ² = 0.226, P = 0.634, log-rank test).

CONCLUSION

Targeted puncture of the left branch of the intrahepatic portal vein during TIPS may reduce the risk of HE but has no direct influence on prognosis of portal-hypertension-related complications.