Reversal of Low-Grade Cerebral Edema After Lactulose/Rifaximin Therapy in Patients with Cirrhosis and Minimal Hepatic Encephalopathy

The RIVET RCT: Rifamycin SV MMX improves muscle mass, physical function, and ammonia in cirrhosis and minimal encephalopathy

BACKGROUND

Minimal hepatic encephalopathy (MHE) negatively affects the prognosis of cirrhosis, but treatment is not standard. Rifamycin SV MMX (RiVM) is a nonabsorbable rifampin derivative with colonic action.

METHODS

In a phase 2 placebo-controlled, double-blind randomized clinical trial patients with MHE were randomized to RiVM or placebo for 30 days with a 7-day follow-up. The primary endpoint was a change in stool cirrhosis dysbiosis ratio. Gut-brain (cognition, stool/salivary microbiome, ammonia, brain magnetic resonance spectroscopy), inflammation (stool calprotectin/serum cytokines), patient-reported outcomes (sickness impact profile: total/physical/psychosocial, high = worse), and sarcopenia (handgrip, bioelectric impedance) were secondary. Between/within groups and delta (post-pre) comparisons were performed.

RESULTS

Thirty patients (15/group) were randomized and completed the study without safety concerns. While cirrhosis dysbiosis ratio was statistically similar on repeated measures ANOVA (95% CI: -0.70 to 3.5), ammonia significantly reduced (95% CI: 4.4-29.6) in RiVM with changes in stool microbial α/β-diversity. MHE status was unchanged but only serial dotting (which tests motor strength) improved in RiVM-assigned patients. Delta physical sickness impact profile (95% CI: 0.33 = 8.5), lean mass (95% CI: -3.3 to -0.9), and handgrip strength (95% CI: -8.1 to -1.0) improved in RiVM versus placebo. Stool short-chain fatty acids (propionate, acetate, and butyrate) increased post-RiVM. Serum, urine, and stool bile acid profile changed to nontoxic bile acids (higher hyocholate/ursodeoxycholate and lower deoxycholate/lithocholate) post-RiVM. Serum IL-1β and stool calprotectin decreased while brain magnetic resonance spectroscopy showed higher glutathione concentrations in RiVM.

CONCLUSIONS

RiVM is well tolerated in patients with MHE with changes in stool microbial composition and function, ammonia, inflammation, brain oxidative stress, and sarcopenia-related parameters without improvement in cognition. RiVM modulates the gut-brain axis and gut-muscle axis in cirrhosis.

The Glymphatic System May Play a Vital Role in the Pathogenesis of Hepatic Encephalopathy: A Narrative Review

Hepatic encephalopathy (HE) is a neurological complication of liver disease resulting in cognitive, psychiatric, and motor symptoms. Although hyperammonemia is a key factor in the pathogenesis of HE, several other factors have recently been discovered. Among these, the impairment of a highly organized perivascular network known as the glymphatic pathway seems to be involved in the progression of some neurological complications due to the accumulation of misfolded proteins and waste substances in the brain interstitial fluids (ISF). The glymphatic system plays an important role in the clearance of brain metabolic derivatives and prevents aggregation of neurotoxic agents in the brain ISF. Impairment of it will result in aggravated accumulation of neurotoxic agents in the brain ISF. This could also be the case in patients with liver failure complicated by HE. Indeed, accumulation of some metabolic by-products and agents such as ammonia, glutamine, glutamate, and aromatic amino acids has been reported in the human brain ISF using microdialysis technique is attributed to worsening of HE and correlates with brain edema. Furthermore, it has been reported that the glymphatic system is impaired in the olfactory bulb, prefrontal cortex, and hippocampus in an experimental model of HE. In this review, we discuss different factors that may affect the function of the glymphatic pathways and how these changes may be involved in HE.

Review article: controversies surrounding the use of carvedilol and other beta blockers in the management of portal hypertension and cirrhosis

BACKGROUND

Advanced chronic liver disease is an increasing cause of premature morbidity and mortality in the UK. Portal hypertension is the primary driver of decompensation, including the development of ascites, hepatic encephalopathy and variceal haemorrhage. Non-selective beta blockers (NSBB) reduce portal pressure and are well established in the prevention of variceal haemorrhage. Carvedilol, a newer NSBB, is more effective at reducing portal pressure due to additional α-adrenergic blockade and has additional anti-oxidant, anti-inflammatory and anti-fibrotic effects.

AIM

To summarise the available evidence on the use of beta blockers, specifically carvedilol, in cirrhosis, focussing on when and why to start METHODS: We performed a comprehensive literature search of PubMed for relevant publications.

RESULTS

International guidelines advise the use of NSBB in primary prophylaxis against variceal haemorrhage in those with high-risk varices, with substantial evidence of efficacy comparable with endoscopic band ligation (EBL). NSBB are also well established in secondary prophylaxis, in combination with EBL. More controversial is their use in patients without large varices, but with clinically significant portal hypertension. However, there is gathering evidence that NSBB, particularly carvedilol, reduce the risk of decompensation and improve survival. While caution is advised in patients with advanced cirrhosis and refractory ascites, recent evidence suggests that NSBB can continue to be used safely, and that premature discontinuation may be detrimental.

CONCLUSIONS

With increasing evidence of benefit independent of variceal bleeding, namely retardation of decompensation and improvement in survival, it is time to consider whether carvedilol should be offered to all patients with advanced chronic liver disease.

Minimal Hepatic Encephalopathy Affects Daily Life of Cirrhotic Patients: A Viewpoint on Clinical Consequences and Therapeutic Opportunities

Minimal hepatic encephalopathy (MHE) is a frequent complication of hepatic encephalopathy (HE) and can affect up to 80% of patients with liver cirrhosis. It is characterized by the lack of obvious clinical signs and the presence of alterations detectable using psychometric or electrophysiological testing focused on attention, working memory, psychomotor speed and visuospatial ability. Ideally, each patient should be tested for this condition because, despite the absence of symptoms, it has severe repercussions on daily life activities. It may be responsible for an inability to drive, sleep disturbances, risk of falls and inability to work. Some studies have highlighted its prognostically unfavorable role on mortality and risk of "overt" HE (OHE). Finally, MHE severely affects the lives of patients and caregivers, altering their quality of life and their socioeconomic status. Several treatments have been proposed for MHE treatment, including non-absorbable disaccharides, poorly absorbable antibiotics, such as rifaximin, probiotics and branched-chain amino acids, with promising results. For this reason, early diagnosis and intervention with appropriate measures is essential, with the aim of improving both performance on psychometric tests, as well as clinical aspects related to this condition.

Psychometric methods for diagnosing and monitoring minimal hepatic encephalopathy -current validation level and practical use

Hepatic encephalopathy (HE) is cerebral dysfunction caused by liver failure and inflicts 30-40% of patients with liver cirrhosis during their disease course. Clinically manifest HE is often preceded by minimal HE (MHE) - a clinically undetectable cognitive disturbance closely associated with loss of quality of life. Accordingly, detecting and treating MHE improve the patients' daily functioning and prevent HE-related hospital admissions. The scope of this review article is to create an overview of the validation level and usage of psychometric tests used to detect MHE: Portosystemic hepatic encephalopathy test, continuous reaction time test, Stroop EncephalApp, animal naming test, critical flicker frequency test, and inhibitory control test. Our work is aimed at the clinician or scientist who is about to decide on which psychometric test would fit best in their clinic, cohort, or study. First, we outline psychometric test validation obstacles and requirements. Then, we systematically approach the literature on each test and select well-conducted studies to answer the following questions:• Which percentage of patients with cirrhosis does the test deem as having MHE?• Is the test able to predict clinically manifest HE?• Is there a well-known test-retest variation and inter-observer variation?• Is the test able to detect a treatment response?• Is the test result affected by age, educational level, gender, or comorbidities?

Hepatic encephalopathy: Novel insights into classification, pathophysiology and therapy

Hepatic encephalopathy (HE) is a frequent and serious complication of both chronic liver disease and acute liver failure. HE manifests as a wide spectrum of neuropsychiatric abnormalities, from subclinical changes (mild cognitive impairment) to marked disorientation, confusion and coma. The clinical and economic burden of HE is considerable, and it contributes greatly to impaired quality of life, morbidity and mortality. This review will critically discuss the latest classification of HE, as well as the pathogenesis and pathophysiological pathways underlying the neurological decline in patients with end-stage liver disease. In addition, management strategies, diagnostic approaches, currently available therapeutic options and novel treatment strategies are discussed.

Interplay of cardiovascular mediators, oxidative stress and inflammation in liver disease and its complications

The liver is a crucial metabolic organ that has a key role in maintaining immune and endocrine homeostasis. Accumulating evidence suggests that chronic liver disease might promote the development of various cardiac disorders (such as arrhythmias and cardiomyopathy) and circulatory complications (including systemic, splanchnic and pulmonary complications), which can eventually culminate in clinical conditions ranging from portal and pulmonary hypertension to pulmonary, cardiac and renal failure, ascites and encephalopathy. Liver diseases can affect cardiovascular function during the early stages of disease progression. The development of cardiovascular diseases in patients with chronic liver failure is associated with increased morbidity and mortality, and cardiovascular complications can in turn affect liver function and liver disease progression. Furthermore, numerous infectious, inflammatory, metabolic and genetic diseases, as well as alcohol abuse can also influence both hepatic and cardiovascular outcomes. In this Review, we highlight how chronic liver diseases and associated cardiovascular effects can influence different organ pathologies. Furthermore, we explore the potential roles of inflammation, oxidative stress, vasoactive mediator imbalance, dysregulated endocannabinoid and autonomic nervous systems and endothelial dysfunction in mediating the complex interplay between the liver and the systemic vasculature that results in the development of the extrahepatic complications of chronic liver disease. The roles of ageing, sex, the gut microbiome and organ transplantation in this complex interplay are also discussed.

Laboratory Abnormalities of Hepatic Encephalopathy

Currently, there is no gold standard serologic or imaging modality to detect hepatic encephalopathy (HE). It is a clinical diagnosis gathered from the history and physical. Imaging is nonspecific; however, PET and MRI have shown areas of utility, but are not widely available, cost-efficient, or necessary for diagnosis. Electroencephalogram has shown promise as it can be used in conjunction with the Portal Systemic Hepatic Encephalopathy Score test to diagnose minimal HE. Further research on these techniques would need to be performed to identify strict criteria and cutoffs for diagnosing HE as well as associated sensitivities and specificities.

EncephalApp Stroop App predicts poor sleep quality in patients with minimal hepatic encephalopathy due to hepatitis B-induced liver cirrhosis

BACKGROUND/AIM

A novel computerised Stroop test- EncephalApp Stroop App (EncephalApp) has good diagnostic validity for minimal hepatic encephalopathy (MHE) in cirrhotic patients. The Stroop test is correlated with sleep disturbances which are common, and severely affects health-related quality of life in cirrhotic patients with MHE. We evaluated the relationship between sleep quality and EncephalApp results in patients with MHE due to hepatitis B-induced liver cirrhosis.

PATIENTS AND METHODS

We enrolled 180 adult patients with hepatitis B-induced cirrhosis. All patients were tested using the psychometric hepatic encephalopathy score (PHES) and EncephalApp. We analysed the diagnostic validity of EncephalApp for MHE using PHES as the gold standard for reference. The sleep quality of included patients was evaluated using the Pittsburgh Sleep Quality Index (PSQI). The predictive factors for poor sleep quality were analysed using backwards conditional stepwise logistic regression analysis.

RESULTS

Ninety-eight patients (54.4%) were diagnosed with MHE by PHES. Receiver operating characteristic (ROC) curve analysis showed that the threshold value of EncephalApp for MHE diagnosis was 225.60 s. EncephalApp showed 85.2% sensitivity and 77.3% specificity for diagnosing MHE; the area under the ROC curve was 0.864. PSQI scores of cirrhotic patients with MHE were significantly lower than those without MHE (P < 0.05). Child Turcotte Pugh grades (Odds ratio [OR] = 2.11 [1.55-2.85], P < 0.01) and the total Off-time plus On-time of EncephalApp (OR = 4.14 [1.95-6.29], P < 0.01) were independent predictors of poor sleep quality in MHE patients.

CONCLUSIONS

The total Off-time plus On-time of EncephalApp predicts poor sleep quality in patients with MHE due to hepatitis B-induced cirrhosis.

The Direct Contribution of Astrocytes and Microglia to the Pathogenesis of Hepatic Encephalopathy

Hepatic encephalopathy is a neurological complication resulting from loss of hepatic function and is associated with poor clinical outcomes. During acute liver failure over 20% of mortality can be associated with the development of hepatic encephalopathy. In patients with liver cirrhosis, 1-year survival for those that develop overt hepatic encephalopathy is under 50%. The pathogenesis of hepatic encephalopathy is complicated due to the multiple disruptions in homeostasis that occur following a reduction in liver function. Of these, elevations of ammonia and neuroinflammation have been shown to play a significant contributing role to the development of hepatic encephalopathy. Disruption of the urea cycle following liver dysfunction leads to elevations of circulating ammonia, which enter the brain and disrupt the functioning of astrocytes. This results in dysregulation of metabolic pathways in astrocytes, oxidative stress and cerebral edema. Besides ammonia, circulating chemokines and cytokines are increased following liver injury, leading to activation of microglia and a subsequent neuroinflammatory response. The combination of astrocyte dysfunction and microglia activation are significant contributing factors to the pathogenesis of hepatic encephalopathy.

Cerebral water content mapping in cirrhosis patients with and without manifest HE

Hepatic encephalopathy (HE) is a frequent and debilitating complication of cirrhosis and its pathogenesis is not definitively clarified. Recent hypotheses focus on the possible existence of low-grade cerebral edema due to accumulation of osmolytes secondary to hyperammonemia. In the present study we investigated increases in cerebral water content by a novel magnetic resonance impedance (MRI) technique in cirrhosis patients with and without clinically manifest HE. We used a 3 T MRI technique for quantitative cerebral water content mapping in nine cirrhosis patients with an episode of overt HE, ten cirrhosis patients who never suffered from HE, and ten healthy aged-matched controls. We tested for differences between groups by statistical non-parametric mapping (SnPM) for a voxel-based spatial evaluation. The patients with HE had significantly higher water content in white matter than the cirrhosis patients (0.6%), who in turn, had significantly higher content than the controls (1.7%). Although the global gray matter water content did not differ between the groups, the patients with HE had markedly higher thalamic water content than patients who never experienced HE (6.0% higher). We found increased white matter water content in cirrhosis patients, predominantly in those with manifest HE. This confirms the presence of increasing degrees of low-grade edema with exacerbation of pathology. The thalamic edema in manifest HE may lead to compromised basal ganglia-thalamo-cortical circuits, in accordance with the major clinical symptoms of HE. The identification of the thalamus as particularly inflicted in manifest HE is potentially relevant to the pathophysiology of HE.

Brain Edema in Chronic Hepatic Encephalopathy

Brain edema is a common feature associated with hepatic encephalopathy (HE). In patients with acute HE, brain edema has been shown to play a crucial role in the associated neurological deterioration. In chronic HE, advanced magnetic resonance imaging (MRI) techniques have demonstrated that low-grade brain edema appears also to be an important pathological feature. This review explores the different methods used to measure brain edema ex vivo and in vivo in animal models and in humans with chronic HE. In addition, an in-depth description of the main studies performed to date is provided. The role of brain edema in the neurological alterations linked to HE and whether HE and brain edema are the manifestations of the same pathophysiological mechanism or two different cerebral manifestations of brain dysfunction in liver disease are still under debate. In vivo MRI/magnetic resonance spectroscopy studies have allowed insight into the development of brain edema in chronic HE. However, additional in vivo longitudinal and multiparametric/multimodal studies are required (in humans and animal models) to elucidate the relationship between liver function, brain metabolic changes, cellular changes, cell swelling, and neurological manifestations in chronic HE.

Application of tabu search-based Bayesian networks in exploring related factors of liver cirrhosis complicated with hepatic encephalopathy and disease identification

This study aimed to explore the related factors and strengths of hepatic cirrhosis complicated with hepatic encephalopathy (HE) by multivariate logistic regression analysis and tabu search-based Bayesian networks (BNs), and to deduce the probability of HE in patients with cirrhosis under different conditions through BN reasoning. Multivariate logistic regression analysis indicated that electrolyte disorders, infections, poor spirits, hepatorenal syndrome, hepatic diabetes, prothrombin time, and total bilirubin are associated with HE. Inferences by BNs found that infection, electrolyte disorder and hepatorenal syndrome are closely related to HE. Those three variables are also related to each other, indicating that the occurrence of any of those three complications may induce the other two complications. When those three complications occur simultaneously, the probability of HE may reach 0.90 or more. The BN constructed by the tabu search algorithm can analyze not only how the correlative factors affect HE but also their interrelationships. Reasoning using BNs can describe how HE is induced on the basis of the order in which doctors acquire patient information, which is consistent with the sequential process of clinical diagnosis and treatment.

Understanding the impact of neurologic complications in patients with cirrhosis

Patients with cirrhosis may experience neurologic complications, including hepatic encephalopathy. Hepatic encephalopathy may be classified as covert (mild symptoms (e.g. lack of awareness)) or overt (moderate to severe symptoms (e.g. confusion or coma)), and symptoms may overlap with other neurologic conditions (e.g. epilepsy, stroke). Managing hepatic encephalopathy includes identifying and treating precipitating factors (e.g. dehydration). First-line treatment for patients with overt hepatic encephalopathy is typically lactulose; to reduce the risk of overt hepatic encephalopathy recurrence, lactulose plus the nonsystemic antibiotic rifaximin is recommended. Rifaximin reduced the risk of breakthrough overt hepatic encephalopathy by 58% versus placebo over 6 months (p < 0.001; 91% of patients in each group were on concomitant lactulose). However, neither pharmacologic hepatic encephalopathy treatment nor liver transplantation may completely reverse neurologic impairment in patients with hepatic encephalopathy. Additional neurologic considerations for patients with cirrhosis include preventing falls, as well as managing sleep-related issues, hyponatremia, and cerebral edema. Thus, monitoring neurologic impairment is an important component in the management of patients with cirrhosis.

Diagnosis of covert hepatic encephalopathy: a multi-center study testing the utility of single versus combined testing

Covert hepatic encephalopathy (CHE) affects cognition in a multidimensional fashion. Current guidelines recommend performing Psychometric Hepatic Encephalopathy Score (PHES) and a second test to diagnose CHE for multi-center trials. We aimed to determine if a two-test combination strategy improved CHE diagnosis agreement, and accuracy to predict overt hepatic encephalopathy (OHE), compared to single testing. Cirrhotic outpatients without baseline OHE performed PHES, Inhibitory Control Test (ICT), and Stroop EncephAlapp (StE) at three centers. Patients were followed for OHE development. Areas under the receiver operation characteristic curve (AUROC) were calculated. We included 437 patients (399 with follow-up data). CHE prevalence varied with testing strategy: PHES+ICT 18%, ICT + StE 25%, PHES+StE 29%, ICT 35%, PHES 37%, and StE 54%. Combination with best test agreement was PHES+StE (k = 0.34). Sixty patients (15%) developed OHE. Although CHE by StE showed the highest sensitivity to predict OHE, PHES and PHES+StE were more accurate at the expense of a lower sensitivity (55%, AUROC: 0.587; 36%, AUROC: 0.629; and 29%, AUROC: 0.623; respectively). PHES+ICT was the most specific (85%) but all strategies including ICT showed sensitivities in the 33-45% range. CHE diagnosis by PHES (HR = 1.79, p = 0.04), StE (HR = 1.69, p = 0.04), and PHES+StE (HR = 1.72, p = 0.04), were significant OHE predictors even when adjusted for prior OHE and MELD. Our results demonstrate that combined testing decreases CHE prevalence without improving the accuracy of OHE prediction. Testing with PHES or StE alone, or a PHES+StE combination, is equivalent to diagnose CHE and predict OHE development in a multi-center setting.

A, Ravishankar, Reddy DC, Dhiman RK. Prevalence of Minimal Hepatic Encephalopathy in Patients With Liver Cirrhosis: A Cross-Sectional, Clinicoepidemiological, Multicenter, Nationwide Study in India: The PREDICT Study

BACKGROUND

The study aimed at assessing the prevalence and clinical profile of minimal hepatic encephalopathy (MHE) in patients with cirrhosis using neuropsychological assessment and at understanding the management practices of MHE in the Indian clinical setting.

METHODS

This cross-sectional, clinicoepidemiological study conducted at 20 sites enrolled liver cirrhosis patients with Grade 0 hepatic encephalopathy according to West-Haven Criteria. Patients were subjected to mini-mental state examination and those with a score of ≥24 were assessed using psychometric hepatic encephalopathy score. Short Form-36 questionnaire was administered to assess the impact on health-related quality of life.

RESULTS

Of the 1260 enrolled patients, 1114 were included in the analysis. The mean age was 49.5 years and majority were males (901 [81%]). The prevalence of MHE was found to be 59.7% (665/1114) based on the psychometric hepatic encephalopathy score of ≤-5. Alcohol-related liver disease was the most common etiology (482 [43.27%]) followed by viral infection (239 [21.45%]). Past smokers as well as those currently smoking were more likely to have MHE than nonsmokers. A significant association was found between tobacco chewing, smoking, alcohol consumption, diabetes, and the presence of MHE. Multivariable analysis revealed smoking as the only parameter associated with MHE. A total of 300 (26.9%) patients were on prophylaxis with lactulose/lactitol or rifaximin. These patients were less likely to have MHE as compared to those not on prophylaxis (odds ratio, 0.67; 95% confidence interval, 0.50-0.88; P = 0.005).

CONCLUSION

The disease burden of MHE is quite substantial in patients with cirrhosis with no apparent cognitive defect. Smoking, whether past or current, has significant association with the presence of MHE. Although MHE has been shown to adversely affect quality of life, prophylaxis for MHE is not routinely practiced in the Indian setting.The study has been registered under clinical trials registry of India (CTRI/2014/01/004306).

Brain Integrity Changes Underlying Cognitive and Functional Recovery Postliver Transplant Continue to Evolve Over 1 Year

BACKGROUND

There is evidence of brain recovery on brain magnetic resonance imaging (MRI) early postliver transplant (LT), but the longer-term impact is unclear. The aim of this study was to determine the change in brain MRI parameters, cognition, and health-related quality of life (HRQOL) between 6 and 12 months post-LT.

METHODS

Listed cirrhotics underwent cognitive, HRQOL and brain MRI pre-LT, 6 months (post-LT1), and 1-year (post-LT2) post-LT. Assessment of MRI changes between visits was performed for ammonia-associated metabolite changes using magnetic resonance spectroscopy, white matter changes using tract-based spatial statistics analysis on diffusion tensor imaging data and grey matter changes using voxel-based morphometry analysis on 3D high resolution T1-weighted images.

RESULTS

Forty-five patients were included, of which 23 were tested at all visits. Cognitive and HRQOL scores improved between all visits compared with pre-LT values. This trend continued on magnetic resonance spectroscopy with reduced glutamine + glutamate and higher myoinositol, choline between pre-LT/post-LT1 but lower degrees of improvement between post-LT1/post-LT2. On diffusion tensor imaging, mean diffusivity, linear diffusivity and mode of anisotropy continued to increase in the posterior internal capsule at both post-LT visits. On voxel-based morphometry, a continued increase was seen in basal ganglia grey matter between both post-LT visits was seen.

CONCLUSIONS

HRQOL and cognition continue to improve compared with pre-LT values up to 1 year post-LT, although the rate of improvement slows down after 6 months. Grey matter increase is steady over time at 1 year although changes in ammonia-related metabolites and white matter integrity improve at a slower pace at 1 year post-LT.

METH-Induced Neurotoxicity Is Alleviated by Lactulose Pretreatment Through Suppressing Oxidative Stress and Neuroinflammation in Rat Striatum

Abuse of methamphetamine (METH) results in neurological and psychiatric abnormalities. Lactulose is a poorly absorbed derivative of lactose and can effectively alleviate METH-induced neurotoxicity in rats. The present study was designed to investigate the effects of lactulose on METH-induced neurotoxicity. Rats received METH (15 mg/kg, 8 intraperitoneal injections, 12-h interval) or saline and received lactulose (5.3 g/kg, oral gavage, 12-h interval) or vehicle 2 days prior to the METH administration. Reactive oxygen species (ROS) and malondialdehyde (MDA) were measured. Protein levels of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), tumor necrosis factor receptor associated factor 6 (TRAF6), nuclear factor κB (NFκB), interleukin (IL)-1β, IL-6, TNF-α, cleaved caspase 3, and poly(ADP-ribose) polymerase-1 (PARP-1) were determined by western blotting. mRNA expressions of nuclear factor erythroid 2-relatted factor-2 (Nrf2), p62, and heme oxygenase-1 (HO-1) were assessed by RT-qPCR. The lactulose pretreatment decreased METH-induced cytoplasmic damage in rat livers according to histopathological observation. Compared to the control group, overproduction of ROS and MDA were observed in rat striatums in the METH alone-treated group, while the lactulose pretreatment significantly attenuated the METH-induced up-regulation of oxidative stress. The lactulose pretreatment significantly repressed over-expressions of proteins of TLR4, MyD88, TRAF6, NFκB, IL-1β, IL-6, TNF-α, cleaved caspase 3, PARP-1. The lactulose pretreatment increased mRNA expressions of Nrf2, p62, and HO-1. These findings suggest that lactulose pretreatment can alleviate METH-induced neurotoxicity through suppressing neuroinflammation and oxidative stress, which might be attributed to the activation of the Nrf2/HO-1 axis.

Pathogenesis of Hepatic Encephalopathy in Chronic Liver Disease

Hepatic encephalopathy (HE) is a complex neuropsychiatric syndrome that occurs during chronic liver disease (CLD). While ammonia and other precipitating factors in liver disease including inflammation, bile acids, oxidative stress, and lactate play a role in the pathogenesis of HE, the exact mechanism that leads to HE is not fully understood. Notably, accumulating evidence points toward a synergic effect rather than independent actions among precipitating factors that contributes to the development and severity of HE in CLD. Hence, this review is aimed to briefly discuss the single and synergic interplay of pathological factors in the progression and severity of HE.

The burden of minimal hepatic encephalopathy: from diagnosis to therapeutic strategies

Minimal hepatic encephalopathy (MHE) is the mildest form of hepatic encephalopathy (HE). It affects the performance of psychometric tests focused on attention, working memory, psychomotor speed, and visuospatial ability, as well as electrophysiological and other functional brain measures. MHE is a frequent complication of liver disease, affecting up to 80% of tested patients. By being related to falls, an impairment in fitness to drive and the development of overt HE, MHE severely affects the lives of patients and caregivers by altering their quality of life and their socioeconomic status. MHE is detected in clinically asymptomatic patients using appropriate psychometric tests and neurophysiological methods that highlight neuropsychological alterations, such as video-spatial orientation deficits, attention disorders, memory, reaction times, electroencephalogram slowing, prolongation of latency-evoked cognitive potentials, and reduction in the critical flicker frequency. Several treatments have been proposed for MHE treatment, including non-absorbable disaccharides, poorly absorbable antibiotics such as rifaximin, probiotics and branched-chain amino acids. However, because of the multiple diagnosis methods, the various endpoints of treatment trials and the variety of agents used in trials, the treatment of MHE is not currently recommended as routine, but only on a case-by-case basis.

Characterization of Cerebral Edema in Acute-on-Chronic Liver Failure

BACKGROUND AND AIMS

The nature of cerebral edema in acute-on-chronic liver failure (ACLF) is not well studied. We aimed to characterize cerebral edema in ACLF using magnetization transfer ratio (MTR) and diffusion tensor imaging (DTI).

METHODS

Forty-six patients with cirrhosis and acute decompensation were included. Patients were divided into groups A (no cerebral failure, n = 39) and B (cerebral failure, n = 7). Group A was subdivided into no-ACLF (n = 11), grade 1 (n = 10), grade 2 (n = 9) and grade 3 (n = 9) ACLF as per CANONIC study. MRI brain and plasma TNF-alpha, IL-1beta and IL-6 were measured at baseline and 7-10 days after admission. Ten age- and sex-matched healthy controls were also included.

RESULTS

Mean diffusivity (MD) values, an MRI marker of water content, progressively increased from controls to no-ACLF to ACLF grade 1, 2 and 3 in group A in frontal white matter (FWM) and basal ganglia (P < 0.0001). MD values improved only in survivors on follow-up. MD values correlated with IL-6 levels at baseline. On multivariate analysis MELD score ≥28 and MD values (>8 × 10^-9 M²/s) in FWM were independent predictors of 90-day mortality. There was no significant difference in clinical and MRI parameters between group A and B.

CONCLUSION

Cerebral edema increases with severity of ACLF. Correlation between MD values and IL-6 levels suggests pathogenic role of inflammation in cerebral edema. Patients with grade 3 ACLF have cerebral edema irrespective of presence of clinically evident cerebral failure. MELD score and cerebral edema have prognostic significance in ACLF.

Minimal hepatic encephalopathy in children with chronic liver disease: Prevalence, pathogenesis and magnetic resonance-based diagnosis

BACKGROUND & AIMS

Data on minimal hepatic encephalopathy (MHE) in children is scarce. We aimed to study MHE in children with chronic liver disease (CLD) and to validate non-invasive objective tests which can assist in its diagnosis.

METHODS

We evaluated 67 children with CLD (38 boys; age 13 [7-18] years) and 37 healthy children to determine the prevalence of MHE. We also assessed the correlation of MHE with changes in brain metabolites by magnetic resonance spectroscopy (¹HMRS), diffusion tensor imaging (DTI) derived metrics, blood ammonia and inflammatory cytokines (interleukin-6 [IL6], tumor necrosis factor alpha [TNF-α]). In addition, the accuracy of MR-based investigations for diagnosis of MHE in comparison to neuropsychological tests was analysed.

RESULTS

Thirty-four (50.7%) children with CLD had MHE on neuropsychological tests. MHE patients had higher BA (30.5 [6-74] vs. 14 [6-66]μmol/L; p=0.02), IL-6 (8.3 [4.7-28.7] vs. 7.6 [4.7-20.7]pg/ml; p=0.4) and TNF-α (17.8 [7.8-65.5] vs. 12.8 [7.5-35]pg/ml; p=0.06) than No-MHE. ¹HMRS showed higher glutamine (2.6 [2.1-3.3] vs. 2.4 [2.0-3.1]; p=0.02), and lower choline (0.20 [0.14-0.25] vs. 0.22 [0.17-0.28]; p=0.1) and myo-inositol (0.25 [0.14-0.41] vs. 0.29 [0.21-0.66]; p=0.2) in MHE patients than those without MHE. Mean diffusivity (MD) on DTI was significantly higher in 6/11 brain areas in patients with MHE vs. no MHE. Brain glutamine had a significant positive correlation with blood ammonia, IL-6, TNF-α and MD of various brain regions. Neuropsychological tests showed a negative correlation with blood ammonia, IL6, TNF-α, glutamine and MD. Frontal white matter MD had a sensitivity and specificity of 73.5% and 100% for diagnosing MHE.

CONCLUSIONS

In children with CLD, 50% have MHE. There is a significant positive correlation between markers of hyperammonemia, inflammation and brain edema and these correlate negatively with neuropsychological tests. MD on DTI is a reliable tool for diagnosing MHE.

LAY SUMMARY

Fifty percent of children with chronic liver disease develop minimal hepatic encephalopathy (MHE) and perform poorly on neuropsychological testing. These children have raised blood ammonia, inflammatory cytokines and mild cerebral edema on diffusion tensor imaging as compared to children without MHE. The higher the ammonia, inflammatory cytokines and cerebral edema levels the poorer the performance on neuropsychological assessment. The estimation of mean diffusivity on diffusion tensor imaging is an objective and reliable method for diagnosing MHE.

Brain Training with Video Games in Covert Hepatic Encephalopathy

Despite the associated adverse outcomes, pharmacologic intervention for covert hepatic encephalopathy (CHE) is not the standard of care. We hypothesized that a video game-based rehabilitation program would improve white matter integrity and brain connectivity in the visuospatial network on brain magnetic resonance imaging (MRI), resulting in improved cognitive function in CHE subjects on measures consistent with the cognitive skill set emphasized by the two video games (e.g., IQ Boost-visual working memory, and Aim and Fire Challenge-psychomotor speed), but also generalize to thinking skills beyond the focus of the cognitive training (Hopkins verbal learning test (HVLT)-verbal learning/memory) and improve their health-related quality of life (HRQOL). The trial included three phases over 8 weeks; during the learning phase (cognitive tests administered twice over 2 weeks without intervening intervention), training phase (daily video game training for 4 weeks), and post-training phase (testing 2 weeks after the video game training ended). Thirty CHE patients completed all visits with significant daily achievement on the video games. In a subset of 13 subjects that underwent brain MRI, there was a significant decrease in fractional anisotropy, and increased radial diffusivity (suggesting axonal sprouting or increased cross-fiber formation) involving similar brain regions (i.e., corpus callosum, internal capsule, and sections of the corticospinal tract) and improvement in the visuospatial resting-state connectivity corresponding to the video game training domains. No significant corresponding improvement in HRQOL or HVLT performance was noted, but cognitive performance did transiently improve on cognitive tests similar to the video games during training. Although multimodal brain imaging changes suggest reductions in tract edema and improved neural network connectivity, this trial of video game brain training did not improve the HRQOL or produce lasting improvement in cognitive function in patients with CHE.

A longitudinal study of patients with cirrhosis treated with L-ornithine L-aspartate, examined with magnetization transfer, diffusion-weighted imaging and magnetic resonance spectroscopy

The presence of overt hepatic encephalopathy (HE) is associated with structural, metabolic and functional changes in the brain discernible by use of a variety of magnetic resonance (MR) techniques. The changes in patients with minimal HE are less well documented. Twenty-two patients with well-compensated cirrhosis, seven of whom had minimal HE, were examined with cerebral 3 Tesla MR techniques, including T₁- and T₂-weighted, magnetization transfer and diffusion-weighted imaging and proton magnetic resonance spectroscopy sequences. Studies were repeated after a 4-week course of oral L-ornithine L-aspartate (LOLA). Results were compared with data obtained from 22 aged-matched healthy controls. There was no difference in mean total brain volume between patients and controls at baseline. Mean cerebral magnetization transfer ratios were significantly reduced in the globus pallidus and thalamus in the patients with cirrhosis irrespective of neuropsychiatric status; the mean ratio was significantly reduced in the frontal white matter in patients with minimal HE compared with healthy controls but not when compared with their unimpaired counterparts. There were no significant differences in either the median apparent diffusion coefficients or the mean fractional anisotropy, calculated from the diffusion-weighted imaging, or in the mean basal ganglia metabolite ratios between patients and controls. Psychometric performance improved in 50 % of patients with minimal HE following LOLA, but no significant changes were observed in brain volumes, cerebral magnetization transfer ratios, the diffusion weighted imaging variables or the cerebral metabolite ratios. MR variables, as applied in this study, do not identify patients with minimal HE, nor do they reflect changes in psychometric performance following LOLA.

Recent developments in the diagnosis and treatment of covert/minimal hepatic encephalopathy

The terms minimal hepatic encephalopathy and covert hepatic encephalopathy are defined. Clinical assessment is unreliable and both require the use of diagnostic tools. Of these, psychometric tests are the most widely used. They require proper standardization and may be biased by patient cooperation or lack thereof. The measure of the critical flicker frequency and of the electroencephalogram, possibly quantified, are also useful. The alteration of any of them is not strictly parallel in size and may vary from patient to patient. When possible, the use of multiple measures might increase diagnostic reliability. These functional measures should be interpreted within the clinical/biochemical profile of the patient to exclude other disorders. A flow chart for treatment is proposed on the basis of current knowledge.

Evaluation of cognitivity, proinflammatory cytokines, and brain magnetic resonance imaging in minimal hepatic encephalopathy induced by cirrhosis and extrahepatic portal vein obstruction

BACKGROUND AND AIMS

Minimal hepatic encephalopathy (MHE) is the mildest form of hepatic encephalopathy (HE) and is characterized by deficits in neurocognitive performance without any clinical symptoms of HE. In the current study, we aim to evaluate and compare the neurocognitive, biochemical, and brain magnetic resonance (MR) imaging changes between patients with cirrhotic MHE and extrahepatic portal vein obstruction (EHPVO) MHE.

METHODS

Thirty-three cirrhotic and 14 EHPVO patients were diagnosed with MHE and were included in the analysis along with 24 normal healthy volunteers. All subjects underwent MR imaging including diffusion tensor imaging and proton MR spectroscopy (¹ H-MRS) followed by cognitive assessments, critical flicker frequency (CFF) measurements, quantification of blood ammonia, and serum proinflammatory cytokine levels.

RESULTS

We observed abnormal neurocognitive functions and CFF measurements in both cirrhotic MHE and EHPVO MHE patients as compared with controls. Significantly increased blood ammonia, serum proinflammatory cytokines (IL-6, TNF-α) level, mean diffusivity in multiple brain sites, ¹ H-MRS derived glutamate/glutamine (Glx)/creatine (Cr), and significantly decreased ¹ H-MRS derived myo-inositol/Cr were observed in both cirrhotic MHE and EHPVO MHE compared with those of controls. Choline/Cr level was significantly decreased in cirrhotic MHE as compared with controls and EHPVO MHE.

CONCLUSIONS

Cirrhotic MHE showed more severe changes on mean diffusivity in multiple brain sites and inflammation as compared with EHPVO MHE. This study confirms that there are significant difference in neurocognitive, biochemical, and MR profile between cirrhotic MHE and EHPVO MHE, which may help to understand the pathophysiologies of these two types of MHE and may contribute to improve their clinical managements.

Clinical effects of joint application of β-sodium aescinate and mannitol in treating early swelling after upper limb trauma surgery

The aim of the present study was to examine the clinical merits of joint application of β-sodium aescinate and mannitol for the treatment of early swelling of upper limb trauma after surgery. We verified whether the expression of serum aquaporin 1 (AQP-1) was involved in swelling mechanism. A total of 102 patients with swelling after upper limb trauma surgery were enrolled into the study and divided randomly into 3 groups (n=34 cases per group). Group A was treated with β-sodium aescinate; group B was treated with with mannitol and group C was treated with both β-sodium aescinate and mannitol. The expression level of AQP-1, and clinical effects and complications before and after treatment were compared§. The time of swelling subsidence in group C was significantly shorter than that of the other two groups and differences were statistically significant (P<0.05). The recovery ratio and total efficiency in group C were significantly higher than those in other two groups and differences were statistically significant (P<0.05). Three and seven days after treatment, the AQP-1 levels in group A and group C were decreased and AQP-1 level decreased further with time. Differences of comparison within groups were statistically significant (P<0.05), although the differences of comparison between the groups showed no statistical significance (P>0.05). We also compared the AQP-1 level in group B before and after treatment, and the differences were not statistically significant (P>0.05). When the complication incidence in the 3 groups was compared, no statistical significance was detected (P>0.05). We concluded that the joint use of β-sodium aescinate and mannitol in treating early swelling after upper limb trauma surgery produced satisfactory outcomes. This might be related to reduction of the AQP-1 level.

Impaired Gut-Liver-Brain Axis in Patients with Cirrhosis

Cirrhosis is associated with brain dysfunction known as hepatic encephalopathy (HE). The mechanisms behind HE are unclear although hyperammonemia and systemic inflammation through gut dysbiosis have been proposed. We aimed to define the individual contribution of specific gut bacterial taxa towards astrocytic and neuronal changes in brain function using multi-modal MRI in patients with cirrhosis. 187 subjects (40 controls, 147 cirrhotic; 87 with HE) underwent systemic inflammatory assessment, cognitive testing, stool microbiota analysis and brain MRI analysis. MR spectroscopy (MRS) changes of increased Glutamate/glutamine, reduced myo-inositol and choline are hyperammonemia-associated astrocytic changes, while diffusion tensor imaging (DTI) demonstrates changes in neuronal integrity and edema. Linkages between cognition, MRI parameters and gut microbiota were compared between groups. We found that HE patients had a significantly worse cognitive performance, systemic inflammation, dysbiosis and hyperammonemia compared to controls and cirrhotics without HE. Specific microbial families (autochthonous taxa negatively and Enterobacteriaceae positively) correlated with MR spectroscopy and hyperammonemia-associated astrocytic changes. On the other hand Porphyromonadaceae, were only correlated with neuronal changes on DTI without linkages with ammonia. We conclude that specific gut microbial taxa are related to neuronal and astrocytic consequences of cirrhosis-associated brain dysfunction.