Stool microbiota are superior to saliva in distinguishing cirrhosis and hepatic encephalopathy using machine learning

BACKGROUND & AIMS

Saliva and stool microbiota are altered in cirrhosis. Since stool is logistically difficult to collect compared to saliva, it is important to determine their relative diagnostic and prognostic capabilities. We aimed to determine the ability of stool vs. saliva microbiota to differentiate between groups based on disease severity using machine learning (ML).

METHODS

Controls and outpatients with cirrhosis underwent saliva and stool microbiome analysis. Controls vs. cirrhosis and within cirrhosis (based on hepatic encephalopathy [HE], proton pump inhibitor [PPI] and rifaximin use) were classified using 4 ML techniques (random forest [RF], support vector machine, logistic regression, and gradient boosting) with AUC comparisons for stool, saliva or both sample types. Individual microbial contributions were computed using feature importance of RF and Shapley additive explanations. Finally, thresholds for including microbiota were varied between 2.5% and 10%, and core microbiome (DESeq2) analysis was performed.

RESULTS

Two hundred and sixty-nine participants, including 87 controls and 182 patients with cirrhosis, of whom 57 had HE, 78 were on PPIs and 29 on rifaximin were included. Regardless of the ML model, stool microbiota had a significantly higher AUC in differentiating groups vs. saliva. Regarding individual microbiota: autochthonous taxa drove the difference between controls vs. patients with cirrhosis, oral-origin microbiota the difference between PPI users/non-users, and pathobionts and autochthonous taxa the difference between rifaximin users/non-users and patients with/without HE. These were consistent with the core microbiome analysis results.

CONCLUSIONS

On ML analysis, stool microbiota composition is significantly more informative in differentiating between controls and patients with cirrhosis, and those with varying cirrhosis severity, compared to saliva. Despite logistic challenges, stool should be preferred over saliva for microbiome analysis.

LAY SUMMARY

Since it is harder to collect stool than saliva, we wanted to test whether microbes from saliva were better than stool in differentiating between healthy people and those with cirrhosis and, among those with cirrhosis, those with more severe disease. Using machine learning, we found that microbes in stool were more accurate than saliva alone or in combination, therefore, stool should be preferred for analysis and collection wherever possible.

Rifaximin-α reduces gut-derived inflammation and mucin degradation in cirrhosis and encephalopathy: RIFSYS randomised controlled trial

BACKGROUND & AIMS

Rifaximin-α is efficacious for the prevention of recurrent hepatic encephalopathy (HE), but its mechanism of action remains unclear. We postulated that rifaximin-α reduces gut microbiota-derived endotoxemia and systemic inflammation, a known driver of HE.

METHODS

In a placebo-controlled, double-blind, mechanistic study, 38 patients with cirrhosis and HE were randomised 1:1 to receive either rifaximin-α (550 mg BID) or placebo for 90 days.

PRIMARY OUTCOME

50% reduction in neutrophil oxidative burst (OB) at 30 days.

SECONDARY OUTCOMES

changes in psychometric hepatic encephalopathy score (PHES) and neurocognitive functioning, shotgun metagenomic sequencing of saliva and faeces, plasma and faecal metabolic profiling, whole blood bacterial DNA quantification, neutrophil toll-like receptor (TLR)-2/4/9 expression and plasma/faecal cytokine analysis.

RESULTS

Patients were well-matched: median MELD (11 rifaximin-α vs. 10 placebo). Rifaximin-α did not lead to a 50% reduction in spontaneous neutrophil OB at 30 days compared to baseline (p = 0.48). However, HE grade normalised (p = 0.014) and PHES improved (p = 0.009) after 30 days on rifaximin-α. Rifaximin-α reduced circulating neutrophil TLR-4 expression on day 30 (p = 0.021) and plasma tumour necrosis factor-α (TNF-α) (p <0.001). Rifaximin-α suppressed oralisation of the gut, reducing levels of mucin-degrading sialidase-rich species, Streptococcus spp, Veillonella atypica and parvula, Akkermansia and Hungatella. Rifaximin-α promoted a TNF-α- and interleukin-17E-enriched intestinal microenvironment, augmenting antibacterial responses to invading pathobionts and promoting gut barrier repair. Those on rifaximin-α were less likely to develop infection (odds ratio 0.21; 95% CI 0.05-0.96).

CONCLUSION

Rifaximin-α led to resolution of overt and covert HE, reduced the likelihood of infection, reduced oralisation of the gut and attenuated systemic inflammation. Rifaximin-α plays a role in gut barrier repair, which could be the mechanism by which it ameliorates bacterial translocation and systemic endotoxemia in cirrhosis.

CLINICAL TRIAL NUMBER

ClinicalTrials.gov NCT02019784.

LAY SUMMARY

In this clinical trial, we examined the underlying mechanism of action of an antibiotic called rifaximin-α which has been shown to be an effective treatment for a complication of chronic liver disease which effects the brain (termed encephalopathy). We show that rifaximin-α suppresses gut bacteria that translocate from the mouth to the intestine and cause the intestinal wall to become leaky by breaking down the protective mucus barrier. This suppression resolves encephalopathy and reduces inflammation in the blood, preventing the development of infection.

Hepatic Encephalopathy: From Metabolic to Neurodegenerative

Hepatic encephalopathy (HE) is a neuropsychiatric syndrome of both acute and chronic liver disease. As a metabolic disorder, HE is considered to be reversible and therefore is expected to resolve following the replacement of the diseased liver with a healthy liver. However, persisting neurological complications are observed in up to 47% of transplanted patients. Several retrospective studies have shown that patients with a history of HE, particularly overt-HE, had persistent neurological complications even after liver transplantation (LT). These enduring neurological conditions significantly affect patient's quality of life and continue to add to the economic burden of chronic liver disease on health care systems. This review discusses the journey of the brain through the progression of liver disease, entering the invasive surgical procedure of LT and the conditions associated with the post-transplant period. In particular, it will discuss the vulnerability of the HE brain to peri-operative factors and post-LT conditions which may explain non-resolved neurological impairment following LT. In addition, the review will provide evidence; (i) supporting overt-HE impacts on neurological complications post-LT; (ii) that overt-HE leads to permanent neuronal injury and (iii) the pathophysiological role of ammonia toxicity on astrocyte and neuronal injury/damage. Together, these findings will provide new insights on the underlying mechanisms leading to neurological complications post-LT.

Role of anthraquinones in Cassia occidentalis induced hepato-myo-encephalopathy

ETHNOPHARMACOLOGICAL RELEVANCE

The different plant parts of Cassia occidentalis Linn, (CO) such as root, leaves, seeds and pods have traditionally been used in multifarious medicines for the treatment of dysentery, diarrhea, constipation, fever, eczema, cancer and venereal diseases.

MATERIALS AND METHODS

A systematic search of literature has been done in books and scientific databases like Science Direct, Pubmed, Google Scholar and Scopus etc. These sources were used to compile, analyze and review the information regarding the phytochemistry, toxicology and mechanism of toxicity of CO. The various references on this subject are cited in our review ranging from 1956 to 2019.

RESULTS

Unintentional exposure of CO causes serious pathological condition in children, known as hepato-myo-encephalopathy (HME). The toxicity after CO consumption is associated with the presence of anthraquinones (AQs), a class of secondary plant metabolites. These AQs at high concentrations are known to cause detrimental effects on essential vital organs such as liver, kidney, spleen, brain, muscle and reproductive organs. The animal studies in rodent models as well as clinical investigations have clearly revealed that CO toxicity is associated with enhanced hepatotoxicity serum markers (ALT, AST, and LDH) and presence of necrotic lesions in liver. Furthermore, CO also causes vacuolization in muscle tissue and increases the level of CPK which is a prominent muscle damage marker. Apart from these target organs, CO consumption also causes neuronal damage via disturbing the levels of different proteins such as (GFAP and b-tubulin III). The mechanistic studies show that AQs present in CO have the potential to disturb the cellular homeostasis via binding to DNA, increasing the production ROS and showing inhibitory effects on essential enzymes etc. Therefore, AQs have been observed to be the primary culprit agents contributing to the toxicity of CO in children and animals.

CONCLUSION

Despite its therapeutic potential, CO consumption can be detrimental if consumed in high amounts. A thorough analysis of literature reveals that AQs are the primary factors contributing to toxicity of CO seeds. Exposure to CO seeds causes HME, which is a serious life threatening condition for the malnourished children from lower strata. Multiple mechanisms are involved in the CO induced HME in patients. Lack of appropriate diagnostic measures and a poor understanding of the CO toxicity mechanism in humans and animals complicate the clinical management of CO poisoning subjects. Therefore, development of point of care diagnostic kits shall help in early diagnosis & suitable management of CO poisoning.

Babao Dan improves neurocognitive function by inhibiting inflammation in clinical minimal hepatic encephalopathy

BACKGROUND AND PURPOSE

Inflammation has been considered a precipitating event that contributes to neurocognitive dysfunction in minimal hepatic encephalopathy (MHE). Inhibition TLR-4 related inflammation can effectively improve neurocognitive dysfunction of MHE. Our previous study showed that Babao Dan (BBD) effectively inhibited inflammation and ameliorated neurocognitive function in rats with acute hepatic encephalopathy (HE) and chronic HE. The mechanism may lie in the regulation of TLR4 signaling pathway. Therefore, this study aimed to evaluate the role of BBD in the treatment of MHE patients with cirrhosis and to elucidate the underlying mechanism by which BBD regulated TLR4 pathway to alleviate inflammation.

METHODS

A randomized controlled trial (n = 62) was conducted to evaluate the clinical efficacy between BBD plus lactulose (n = 31) and lactulose alone (n = 31) in MHE patients by testing neurocognitive function (NCT-A and DST), blood ammonia, liver function (ALT, AST and TBIL) and blood inflammation (IL-1β, IL-6 and TNF-α). Afterward, we detected NO, inflammatory cytokines (IL-1β, IL-6 and TNF-α) and the phosphorylation of P65, JNK, ERK as well as P38 in LPS-activated rat primary bone marrow-derived macrophages (BMDMs), peritoneal macrophages (PMs), and mouse primary BMDMs/PMs/microglia/astrocytes, to investigate the underlying mechanism of BBD inhibiting inflammation through TLR4 pathway. Also, the survival rate of mice, liver function (ALT, AST), blood inflammation (IL-1β, IL-6 and TNF-α), inflammatory cytokines (IL-1β, IL-6 and TNF-α) and histopathological changes in the liver, brain and lung were measured to assess the anti-inflammatory effect of BBD on neurocognitive function in endotoxin shock/endotoxemia mice.

RESULTS

BBD combined with lactulose significantly ameliorated neurocognitive function by decreasing NCT-A (p＜0.001) and increasing DST (p＜0.001); inhibited systemic inflammation by decreasing IL-1β (p＜0.001), IL-6(p＜0.001) and TNF-α (p＜0.001); reduced ammonia level (p = 0.005), and improved liver function by decreasing ALT(p = 0.043), AST(p = 0.003) and TBIL (p = 0.026) in MHE patients. Furthermore, BBD inhibited gene and protein expression of IL-1β, IL-6 and TNF-α as well as NO in rat primary BMDMs/PMs, and mouse primary BMDMs/PMs/microglia/astrocytes in a dose-dependent manner. BBD inhibited the activation of mouse primary BMDMs/PMs/microglia/astrocytes by regulating TLR4 pathway involving the phosphorylation of P65, JNK, ERK and P38. Also, BBD reduced the mortality of mice with endotoxin shock/endotoxemia; serum levels of ALT, AST, IL-1β, IL-6 and TNF-α; gene expression of IL-1β, IL-6 and TNF-α in the liver, brain and lung, and tissue damage in the liver and lung.

CONCLUSION

Our study provided for the first time clinical and experimental evidence supporting the use of BBD in MHE, and revealed that BBD could play a crucial role in targeting and regulating TLR4 inflammatory pathway to improve neurocognitive function in MHE patients.

Distinct gut microbial compositional and functional changes associated with impaired inhibitory control in patients with cirrhosis

Most cirrhosis etiologies, such as alcohol, hepatitis C, and obesity, involve behavior that require the loss of inhibitory control. Once cirrhosis develops, patients can also develop cognitive impairment due to minimal hepatic encephalopathy (MHE). Both processes could have distinct imprints on the gut-liver-brain axis. Determine the impact of inhibitory control versus traditional cirrhosis-related cognitive performance on gut microbial composition and function. Outpatients with cirrhosis underwent two tests for MHE: inhibitory control test (MHEICT, computerized associated with response inhibition) and psychometric hepatic encephalopathy score (MHEPHES, paper-pencil HE-specific associated with subcortical impairment) along with stool collection for metagenomics. MHEICT/not, MHEPHES/not, and discordant (positive on one test but negative on the other) were analyzed for demographics, bacterial species, and gut-brain modules (GBM) using multi-variable analyses. Ninety-seven patients [47 (49%) MHEPHES, 76 (78%) MHEICT, 41 discordant] were enrolled. MHEPHES/not: Cirrhosis severity was worse in MHEPHES without differences in alpha/beta diversity on bacterial species or GBMs. Pathobionts (Enterobacteriaceae) and γ-amino-butryic acid (GABA) synthesis GBM were higher in MHEPHES. MHEICT/not: We found similar cirrhosis severity and metagenomic alpha/beta diversity in MHEICT versus not. However, alpha/beta diversity of GBMs were different in MHEICT versus No-MHE patients. Alistipes ihumii, Prevotella copri, and Eubacterium spp. were higher, while Enterococcus spp. were uniquely lower in MHEICT versus no-MHE and discordant comparisons. GBMs belonging to tryptophan, menaquinone, GABA, glutamate, and short-chain fatty acid synthesis were also unique to MHEICT. Gut microbial signature of impaired inhibitory control, which is associated with addictive disorders that can lead to cirrhosis, is distinct from cirrhosis-related cognitive impairment.

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.

Hyponatremia in Cirrhosis: An Update

Hyponatremia is frequently seen in patients with ascites secondary to advanced cirrhosis and portal hypertension. Although not apparent in the early stages of cirrhosis, the progression of cirrhosis and portal hypertension leads to splanchnic vasodilation, and this leads to the activation of compensatory mechanisms such as renin-angiotensin-aldosterone system (RAAS), sympathetic nervous system, and antidiuretic hormone (ADH) to ameliorate low circulatory volume. The net effect is the avid retention of sodium and water to compensate for the low effective circulatory volume, resulting in the development of ascites. These compensatory mechanisms lead to impairment of the kidneys to eliminate solute-free water in decompensated cirrhosis. Nonosmotic secretion of antidiuretic hormone (ADH), also known as arginine vasopressin, further worsens excess water retention and thereby hyponatremia. The management of hyponatremia in this setting is a challenge as conventional therapies for hyponatremia including fluid restriction and correction of hypokalemia are frequently inefficacious. In this review, we discuss the pathophysiology, complications, and various treatment modalities, including albumin infusion, selective vasopressin receptor antagonists, or hypertonic saline for patients with severe hyponatremia and those awaiting liver transplantation.

Prognostic value of hepatic encephalopathy for survival of patients with liver failure: A systematic review and meta-analysis

INTRODUCTION AND OBJECTIVES

The aim of this paper was to evaluate the association of hepatic encephalopathy with survival of patients with liver failure.

MATERIALS AND METHODS

We retrieved the relevant articles from the PubMed, Embase and Cochrane Library, up to May 2017. The pooled odds ratio (OR) as well as their 95% confidence intervals (CI) was calculated by the software of R package version 3.12.

RESULTS

Total 13 studies with 2071 liver failure patients were included and reanalyzed in this meta-analysis. The results proved the prognostic value of hepatic encephalopathy for survival of patients with liver failure (OR=5.62, 95%CI=6.30-9.82, P<0.001). The subgroup analyses showed that the type of liver failure and the follow up duration may be the factor influencing the association between hepatic encephalopathy and survival of patients with liver failure.

CONCLUSIONS

The results proved that hepatic encephalopathy was a prognostic factor of survival in patients with liver failure.

The Molar Ratio of Total Branched-chain Amino Acids to Tyrosine Predicts a Digit Symbol Test Abnormality in Cirrhotic Patients

Objective We aimed to investigate the association between the digit symbol test (DST) and clinical characteristics, including the nutritional status of liver cirrhosis patients. Methods Fifty-nine cirrhotic patients without a history of overt hepatic encephalopathy were retrospectively evaluated. We examined neuropsychological abnormalities (NPAs) using the DST. We also estimated the detailed nutritional status using the Food Frequency Questionnaire (FFQ). The patients were divided into two groups according to their DST status: patients with normal DST scores (DST-Nor group, n=45) and those with abnormal DST scores (DST-Abn group, n=14). The clinical and nutritional findings of the two groups were compared. Results Overall, 14 (23.7%) patients had a DST abnormality. There were significant differences between the two groups in serum albumin (Alb; p=0.0043), valine (Val; p=0.0016), leucine (Leu; p=0.0078), isoleucine (Ile; p=0.0022), the molar ratio of total branched-chain amino acids to tyrosine (BTR; p=0.00025), total-bilirubin (T-Bil; p=0.0071), prothrombin time (%) (PT; p=0.028), and serum sodium (Na; p=0.035). A multivariate analysis found the BTR to be the only independent predictor of a DST abnormality (hazard ratio, 9.24; p<0.031). An FFQ analysis, revealed that the nutritional findings of patients with and without a DST abnormality, were similar. Conclusion The BTR was useful for predicting the risk of NPAs, as defined by a DST abnormality. The risk of NPAs may be estimated by monitoring the BTR.

Important Unresolved Questions in the Management of Hepatic Encephalopathy: An ISHEN Consensus

Management of hepatic encephalopathy (HE) remains challenging from a medical and psychosocial perspective. Members of the International Society for Hepatic Encephalopathy and Nitrogen Metabolism recognized 5 key unresolved questions in HE management focused on (i) driving, (ii) ammonia levels in clinical practice, (iii) testing strategies for covert or minimal HE, (iv) therapeutic options, and (v) nutrition and patient-reported outcomes. The consensus document addresses these topical issues with a succinct review of the literature and statements that critically evaluate the current science and practice, laying the groundwork for future investigations.

Aberrant inter-hemispheric coordination characterizes the progression of minimal hepatic encephalopathy in patients with HBV-related cirrhosis

Patients with hepatitis B virus (HBV)-related cirrhosis (HBV-RC) and minimal hepatic encephalopathy (MHE) exhibit alterations in homotopic inter-hemispheric functional connectivity (FC) and corpus callosum (CC) degeneration. However, the progression of inter-hemispheric dysconnectivity in cirrhotic patients from no MHE (NMHE) to MHE and its association with the progression of diseased-related cognitive impairment remain uncharacterized. We hypothesized that inter-hemispheric dysconnectivity exists in NMHE patients and further deteriorates at the MHE stage, which is associated with performance measured by psychometric hepatic encephalopathy scores (PHES) that can characterize cirrhotic patients with NMHE and MHE. Using inter-hemispheric homotopic FC and CC (and its subfields) volumetric measurements in 31 patients with HBV-RC (17 with NMHE and 14 with MHE) and 37 healthy controls, we verified that MHE patients had significant attenuated inter-hemispheric homotopic FC in the bilateral cuneus, post-central gyrus, inferior parietal lobule, and superior temporal gyms, as well as CC degeneration in total CC, CC2, CC3, and CC4 (each comparison had a corrected P < 0.05). In contrast, NMHE patients had relatively less severe inter-hemispheric homotopic FC and no CC degeneration. In addition, the degeneration of the CC and inter-hemispheric homotopic functional disconnections correlated with poor PHES performances in all cirrhotic patients (NMHE and MHE). Furthermore, impairment of inter-hemispheric homotopic FC partially mediated the association between CC degeneration and worse PHES performance. Notably, a combination of inter-hemispheric homotopic FC and CC volumes had higher discriminative values according to the area under the curve (AUC) score (AUC = 0.908, P < 0.001) to classify patients into MHE or NMHE groups when compared with either alone. Our findings shed light on the progression of inter-hemispheric dysconnectivity in relation to the progression of disease-related cognitive impairment in patients with HBV-RC.

Health-related quality of life in patients with compensated and decompensated liver cirrhosis

BACKGROUND

Compensated (Child-Pugh [CP] A) and decompensated (CP B/C) liver cirrhosis significantly differs in terms of impairment of health-related quality of life (HRQoL). However, sufficient data on potentially treatable factors associated with HRQoL in both stages of the disease are still lacking. Consequently, aims of this study were to determine differences in HRQoL between patients with compensated and decompensated liver cirrhosis and to identify potentially treatable factors associated with HRQoL.

METHODS

218 patients with liver cirrhosis were enrolled into this study. Chronic Liver Disease Questionnaire (CLDQ) was used to assess HRQoL. Covert hepatic encephalopathy (CHE) was diagnosed according to a combination of Psychometric Hepatic Encephalopathy Score and Critical Flicker Frequency. Frailty was assessed by Clinical Frailty Scale (CFS).

RESULTS

HRQoL differed between patients with CP A (n = 133) and CP B/C (n = 85) liver cirrhosis (CLDQ total score: 5.6 vs. 4.8, p < 0.001). Multivariate analysis identified a history of falls in the recent year, presence of CHE, female gender, active smoking, higher CFS, and higher serum levels of CRP as independent predictors of impaired HRQoL (all p < 0.05) in patients with CP A liver cirrhosis. In patients with CP B/C liver cirrhosis, female gender, a history of overt hepatic encephalopathy, and lower hemoglobin were independently associated with impaired HRQoL (all p < 0.05).

CONCLUSIONS

Predictors of impaired HRQoL differ in patients with CP A or CP B/C liver cirrhosis. Focusing on treatable factors in routine clinical practice may improve HRQoL in all stages of liver cirrhosis.

A novel neural computational model of generalized periodic discharges in acute hepatic encephalopathy

Acute hepatic encephalopathy (AHE) due to acute liver failure is a common form of delirium, a state of confusion, impaired attention, and decreased arousal. The electroencephalogram (EEG) in AHE often exhibits a striking abnormal pattern of brain activity, which epileptiform discharges repeat in a regular repeating pattern. This pattern is known as generalized periodic discharges, or triphasic-waves (TPWs). While much is known about the neurophysiological mechanisms underlying AHE, how these mechanisms relate to TPWs is poorly understood. In order to develop hypotheses how TPWs arise, our work builds a computational model of AHE (AHE-CM), based on three modifications of the well-studied Liley model which emulate mechanisms believed central to brain dysfunction in AHE: increased neuronal excitability, impaired synaptic transmission, and enhanced postsynaptic inhibition. To relate our AHE-CM to clinical EEG data from patients with AHE, we design a model parameter optimization method based on particle filtering (PF-POM). Based on results from 7 AHE patients, we find that the proposed AHE-CM not only performs well in reproducing important aspects of the EEG, namely the periodicity of triphasic waves (TPWs), but is also helpful in suggesting mechanisms underlying variation in EEG patterns seen in AHE. In particular, our model helps explain what conditions lead to increased frequency of TPWs. In this way, our model represents a starting point for exploring the underlying mechanisms of brain dynamics in delirium by relating microscopic mechanisms to EEG patterns.

Acute mental change as the presenting sign of posthepatectomy hepatic failure: A case report

RATIONALE

Hepatectomy is a treatment to increase survival and curability of patients with intrahepatic lesions or malignant tumors. However, posthepatectomy liver failure (PHLF) can occur. This case is a patient showing acute mental change in postanesthetic care unit (PACU) as an uncommon symptom of PHLF after extended right hepatectomy.

PATIENT CONCERNS

A 68-year-old male patient was admitted for surgery of Klatskin tumor. He had hypertension and atrial fibrillation. His model for end-stage liver disease score was 16 pts. His serum bilirubin and ammonia levels were 4.75 mg/dL and 132.8 mcg/dL, respectively. Other laboratory data were nonspecific. He underwent extended right hepatic lobectomy including segments IV-VIII for 9 hours. Weight of liver specimen was 1028 g which was about 58% of total liver volume based on computed tomographic volumetry. The patient was extubated and moved to the PACU with stable vital sign and regular self-breathing. He could obey verbal commands. Fifteen minutes after admission to the PACU, the patient showed abruptly decreasing mental status and self-breathing.

DIAGNOSES

Brain computed tomography, blood culture, and sputum culture were performed to diagnose brain lesions and sepsis for evaluating the sudden onset comatous mental status. Results showed nonspecific finding.

INTERVENTIONS

He was intubated for securing airway and applying ventilatory care. The patient was moved to the intensive care unit. He received intensive conservative therapy including continuous renal replacement therapy and broad-spectrum antibiotics.

OUTCOMES

The patient's condition was worsened. He expired on postoperative day 3.

LESSONS

Acute mental change is uncommon and rare as initial symptoms of PHLF. Therefore, clinician may overlook the diagnosis of PHLF in patients with acute mental change after hepatectomy. Thus, clinician should plan an aggressive treatment for PHLF including liver transplantation by recognizing any suspicious symptom, although such symptom is rare.

A Mean Field Model of Acute Hepatic Encephalopathy

Acute hepatic encephalopathy (AHE) is a common form of delirium, a state of confusion, impaired attention, and decreased arousal due to acute liver failure. However, the neurophysiological mechanisms underlying AHE are poorly understood. In order to develop hypotheses for mechanisms of AHE, our work builds on an existing neural mean field model for similar EEG patterns in cerebral anoxia, the bursting Liley model. The model proposes that generalized periodic discharges, similar to the triphasic waves (TPWs) seen in severe AHE, arise through three types of processes a) increased neuronal excitability; b) defective brain energy metabolism leading to impaired synaptic transmission; c) and enhanced postsynaptic inhibition mediated by increased GABA-ergic and glycinergic transmission. We relate the model parameters to human EEG data using a particle-filter based optimization method that matches the TPW inter-event-interval distribution of the model with that observed in patients EEGs. In this way our model relates microscopic mechanisms to EEG patterns. Our model represents a starting point for exploring the underlying mechanisms of brain dynamics in delirium.

Sarcopenia and cognitive impairment in liver cirrhosis: A viewpoint on the clinical impact of minimal hepatic encephalopathy

Minimal hepatic encephalopathy (MHE) represents the mildest type of hepatic encephalopathy (HE). MHE is considered as a preclinical stage of HE and is part of a wide spectrum of typical neurocognitive alterations characteristic of patients with liver cirrhosis, particularly involving the areas of attention, alertness, response inhibition, and executive functions. MHE can be detected by testing the patients’ psychometric performance, attention, working memory, psychomotor speed, and visuospatial ability, as well as by means of electrophysiological and other functional brain measures. MHE is very frequent, affecting from 20% up to 80% of patients tested, depending of the diagnostic tools used. Although subclinical, MHE is considered to be clinically relevant. In fact, MHE has been related to the patients’ falls, fitness to drive, and working ability. As a consequence, MHE affects the patients and caregivers lives by altering their quality of life and even their socioeconomic status. Recently sarcopenia, a very common condition in patients with advanced liver disease, has been shown to be strictly related to both minimal and overt HE. Aim of this review is to summarize the most recently published evidences about the emerging relationship between sarcopenia and cognitive impairment in cirrhotic patients and provide suggestions for future research.

Associated vitamin D deficiency is a risk factor for the complication of HCV-related liver cirrhosis including hepatic encephalopathy and spontaneous bacterial peritonitis

The influence of vitamin D, 25-hydroxyvitamin D (25(OH)D), deficiency on hepatitis C virus (HCV)-related cirrhosis had been poorly elucidated especially in patients with hepatic encephalopathy (HE) and spontaneous bacterial peritonitis (SBP). We aimed to investigate the association between vitamin D deficiency and the risk of SBP or HE, including the mortality rate. Serum 25(OH)D levels were prospectively determined in 135 patients. Of them, 45 patients had complications with HE and 45 patients had complications with SBP; 45 cirrhotic patients without complication served as the control group. Vitamin D deficiency was defined as 25(OH)D levels < 20 ng/ml. Receiver operating characteristic (ROC) and Kaplan-Meier method with log-rank test were used in our statistical analysis. Predictors of survival were determined using Cox regression analysis. Serum 25(OH)D levels were significantly (P < 0.05) lower in the HE and SBP groups than in the control group (6.81 ± 2.75, 7.15 ± 2.10, 16.28 ± 6.60, respectively). Moreover, serum 25(OH)D levels were significantly lower in the high HE grade than in the low grade (P < 0.001). Regarding the SBP group, classic SBP was associated with lower 25(OH)D levels compared to other types (P < 0.001). ROC curve revealed that lower 25(OH)D levels less than 7.1 ng/ml and 6.6 ng/ml could predict the mortality in SBP and HE patients, respectively, with high sensitivity and specificity. Serum 25(OH)D levels < 5 ng/ml were associated with significant higher mortality rate (HR = 2.76, P = 0.001). Lower 25(OH)D levels were associated with HE and SBP in cirrhotic patients. In addition, it may be considered a prognostic parameter for the severity of liver cirrhosis.

Pathophysiology of hepatic encephalopathy and future treatment options

Understanding of the pathophysiology of hepatic encephalopathy has conditioned new treatment options. Ammonia detoxification in hepatic encephalopathy is regulated by two enzymes: glutaminase or glutamine synthetase. The first produces ammonia and the second detoxifies the ammonia, which is why treatments are aimed at glutaminase inhibition or glutamine synthetase activation. At present, we know that both enzymes are found not only in the liver, but also in the muscle, intestine, kidney, and brain. Therefore, current treatments can be directed at each enzyme at different sites. Awareness of those potential treatment sites makes different options of approach possible in the patient with hepatic encephalopathy, and each approach should be personalized.

Hepatic Encephalopathy in Cirrhosis: Pathology and Pathophysiology

Neuropathology of hepatic encephalopathy (HE) in cirrhosis is primarily astroglial in nature characterized by Alzheimer type 2 astrocytosis together with activation of microglia indicative of neuroinflammation. Focal loss of neurons may also occur in the basal ganglia, thalamus and cerebellum. Pathophysiology of HE in cirrhosis is multifactorial, involving brain accumulation of ammonia and manganese, systemic and central inflammation, nutritional/metabolic factors and activation of the GABAergic neurotransmitter system. Neuroimaging and spectroscopic techniques reveal early deactivation of the anterior cingulate cortex in parallel with neuropsychological impairment. T1-weighted MR signal hyperintensities in basal ganglia resulting from manganese lead to a novel entity, 'Parkinsonism in cirrhosis'. Elucidation of the pathophysiological mechanisms has resulted in novel therapeutic approaches to HE aimed at reduction of brain ammonia, reduction of systemic and central inflammation, and reduction of GABAergic tone via the discovery of antagonists of the neurosteroid-modulatory site on the GABA receptor complex.

Hepatic Encephalopathy: Definition, Clinical Grading and Diagnostic Principles

In general, hepatic encephalopathy (HE) is defined as a brain dysfunction caused by liver insufficiency and/or portal-systemic blood shunting. This article relates to the so-called type C HE: that is, HE in patients with liver cirrhosis. It manifests as a wide spectrum of neurological or psychiatric abnormalities, ranging from subclinical alterations, detectable only by neuropsychological or neurophysiological assessment, to coma. Several scales have been developed for grading the extent of HE. The most often used is the West Haven criteria (WHC), which differentiate between four grades of clinically overt HE. Patients with liver cirrhosis without clinically overt symptoms of HE but neuropsychological or neurophysiological findings indicating brain dysfunction are considered to have minimal hepatic encephalopathy (MHE). For simplification, some experts suggest differentiating between covert HE (MHE plus grade I HE according to WHC) and overt HE (WHC grades II-IV). Diagnosis of both MHE and overt HE is hampered by the fact that none of the symptoms of HE or the findings in the various diagnostic measures applied are specific. Thus, a diagnosis of HE or MHE can only be made after exclusion of other possible causes of brain dysfunction.

Impaired brain glymphatic flow in experimental hepatic encephalopathy

BACKGROUND & AIMS

Neuronal function is exquisitely sensitive to alterations in the extracellular environment. In patients with hepatic encephalopathy (HE), accumulation of metabolic waste products and noxious substances in the interstitial fluid of the brain is thought to result from liver disease and may contribute to neuronal dysfunction and cognitive impairment. This study was designed to test the hypothesis that the accumulation of these substances, such as bile acids, may result from reduced clearance from the brain.

METHODS

In a rat model of chronic liver disease with minimal HE (the bile duct ligation [BDL] model), we used emerging dynamic contrast-enhanced MRI and mass-spectroscopy techniques to assess the efficacy of the glymphatic system, which facilitates clearance of solutes from the brain. Immunofluorescence of aquaporin-4 (AQP4) and behavioural experiments were also performed.

RESULTS

We identified discrete brain regions (olfactory bulb, prefrontal cortex and hippocampus) of altered glymphatic clearance in BDL rats, which aligned with cognitive/behavioural deficits. Reduced AQP4 expression was observed in the olfactory bulb and prefrontal cortex in HE, which could contribute to the pathophysiological mechanisms underlying the impairment in glymphatic function in BDL rats.

CONCLUSIONS

This study provides the first experimental evidence of impaired glymphatic flow in HE, potentially mediated by decreased AQP4 expression in the affected regions.

LAY SUMMARY

The 'glymphatic system' is a newly discovered brain-wide pathway that facilitates clearance of various substances that accumulate in the brain due to its activity. This study evaluated whether the function of this system is altered in a model of brain dysfunction that occurs in cirrhosis. For the first time, we identified that the clearance of substances from the brain in cirrhosis is reduced because this clearance system is defective. This study proposes a new mechanism of brain dysfunction in patients with cirrhosis and provides new targets for therapy.

Quality of life in patients with minimal hepatic encephalopathy

Minimal hepatic encephalopathy (MHE) represents the mildest type of hepatic encephalopathy (HE). This condition alters the performance of psychometric tests by impairing 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, depending of the diagnostic tools used for the diagnosis. MHE is related to falls, to 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 (QoL) and their socioeconomic status. MHE is detected in clinically asymptomatic patients through appropriate psychometric tests and neurophysiological methods which 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 such as non-absorbable disaccharides, poorly absorbable antibiotics such 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, to date the treatment of MHE is not routinely recommended apart from on a case-by-case basis. Aim of this review is analyze the burden of MHE on QoL of patients and provide a brief summary of therapeutic approaches.

Clinical impact of microbiome in patients with decompensated cirrhosis

Cirrhosis is an increasing cause of morbidity and mortality. Recent studies are trying to clarify the role of microbiome in clinical exacerbation of patients with decompensated cirrhosis. Nowadays, it is accepted that patients with cirrhosis have altered salivary and enteric microbiome, characterized by the presence of dysbiosis. This altered microbiome along with small bowel bacterial overgrowth, through translocation across the gut, is associated with the development of decompensating complications. Studies have analyzed the correlation of certain bacterial families with the development of hepatic encephalopathy in cirrhotics. In general, stool and saliva dysbiosis with reduction of autochthonous bacteria in patients with cirrhosis incites changes in bacterial defenses and higher risk for bacterial infections, such as spontaneous bacterial peritonitis, and sepsis. Gut microbiome has even been associated with oncogenic pathways and under circumstances might promote the development of hepatocarcinogenesis. Lately, the existence of the oral-gut-liver axis has been related with the development of decompensating events. This link between the liver and the oral cavity could be via the gut through impaired intestinal permeability that allows direct translocation of bacteria from the oral cavity to the systemic circulation. Overall, the contribution of the microbiome to pathogenesis becomes more pronounced with progressive disease and therefore may represent an important therapeutic target in the management of cirrhosis.

Acute liver failure and hepatic encephalopathy in exertional heat stroke

A 31-year-old man was brought to Accident & Emergency after collapsing during a race. On presentation, the patient had a temperature of 41.7°C (rectal). External cooling was started immediately. The patient was intubated in view of a Glasgow Coma Scale of 7 and was transferred to theintensive therapy unit. Laboratory results revealed an acute kidney injury, rhabdomyolysis, disseminated intravascular coagulopathy and acute liver failure. The patient was encephalopathic, jaundiced and difficult to sedate. His liver function continued to deteriorate with alanine aminotransferase (ALT) levels reaching 9207 U/L. King's Hospital Liver Centre, London was contacted for a possible liver transplant, and they advised an infusion of N-acetylcysteine. The following day liver function tests improved; thus, transplantation was not performed. The patient failed multiple sedation holds and required a tracheostomy. He continued to spike a fever. Despite no source of sepsis being found, the patient remained on broad spectrum antibiotics to cover for any potential infective causes until day 27. After 15 days, the patient's encephalopathy gradually improved. He was weaned off the ventilator and underwent intense physiotherapy. The patient was discharged from hospital one month after admission.

Learning and Memory Impairments in Patients with Minimal Hepatic Encephalopathy are Associated with Structural and Functional Connectivity Alterations in Hippocampus

Patients with minimal hepatic encephalopathy (MHE) show mild cognitive impairment associated with alterations in attentional and executive networks. There are no studies evaluating the relationship between memory in MHE and structural and functional connectivity (FC) changes in the hippocampal system. This study aimed to evaluate verbal learning and long-term memory in cirrhotic patients with (C-MHE) and without MHE (C-NMHE) and healthy controls. We assessed the relationship between alterations in memory and the structural integrity and FC of the hippocampal system. C-MHE patients showed impairments in learning, long-term memory, and recognition, compared to C-NMHE patients and controls. Cirrhotic patients showed reduced fimbria volume compared to controls. Larger volumes in hippocampus subfields were related to better memory performance in C-NMHE patients and controls. C-MHE patients presented lower FC between the L-presubiculum and L-precuneus than C-NMHE patients. Compared to controls, C-MHE patients had reduced FC between L-presubiculum and subiculum seeds and bilateral precuneus, which correlated with cognitive impairment and memory performance. Alterations in the FC of the hippocampal system could contribute to learning and long-term memory impairments in C-MHE patients. This study demonstrates the association between alterations in learning and long-term memory and structural and FC disturbances in hippocampal structures in cirrhotic patients.

Complications of Cirrhosis in Primary Care: Recognition and Management of Hepatic Encephalopathy

Approximately 3.7% of patients in primary care settings have chronic liver disease, and 18% with chronic liver disease in the specialty care setting have cirrhosis. For cirrhotic patients without complications, prognosis is generally favorable; increased morbidity and mortality are observed when complications (i.e., hepatic encephalopathy [HE]) occur. HE occurs in up to 70% of patients with cirrhosis. Neurologic signs in HE span a wide spectrum, from those not easily apparent (covert) to more clinically obvious signs (overt). Providers should consider overt HE in patients with cirrhosis and signs of impaired cognition, confusion, consciousness and/or personality changes, and/or impaired memory. Overt HE treatment includes identifying and treating precipitating factors and reducing bacterial-derived toxin loads. For acute overt HE, lactulose is first-line treatment. To prevent HE recurrence, lactulose plus rifaximin is recommended. Patients with cirrhosis and HE often present in primary care; recognizing and properly managing HE are important in this setting.

Critical flicker frequency test predicts overt hepatic encephalopathy and survival in patients with liver cirrhosis

BACKGROUND

A critical flicker frequency (CFF) ≤39 Hz identifies cirrhotic patients with minimal hepatic encephalopathy (mHE) and predicts the risk of both overt hepatic encephalopathy (oHE) and mortality in patients with previous episodes of decompensation and/or oHE.

AIMS

Herein, we evaluated the effectiveness of CFF in predicting the first episode of oHE and survival in cirrhotics who had never experienced an episode of oHE.

METHODS

Our cohort study of 134 patients and 150 healthy subjects were examined. A CFF > 39 Hz was considered normal and pathological when ≤39 Hz. The median follow up was 36 months.

RESULTS

At baseline, all controls had CFF > 39 Hz. Ninety-three patients had a CFF > 39 Hz and 41 had a CFF ≤ 39 Hz. The prevalence of CFF ≤ 39 Hz significantly increased with the progression of the Child-Pugh class (p = 0.003). Moreover, the risk of oHE was increased by CFF ≤ 39 (p < 0.001, by log-rank test) [HR = 7.57; CI(3.27-17.50); p < 0.0001, by Cox model] and ammonia [HR = 1.02 CI(1.01-1.03), p = 0.0009]. Both a CFF value ≤ 39 Hz and Child-Pugh class were independent predictors of mortality by Cox model [HR = 1.97; CI(1.01-3.95), p = 0.049; HR = 3.85 CI(1.68-8.83), p = 0.003].

CONCLUSIONS

CFF predicts the first episode of oHE in cirrhotics that had never experienced oHE, and predicts mortality risk. These findings suggest that cirrhotic patients should be routinely screened by CFF.

Which of the branched-chain amino acids increases cerebral blood flow in hepatic encephalopathy? A double-blind randomized trial

Branched-chain amino acids increase the brain perfusion of patients with hepatic encephalopathy (HE), but the amino acid and the mechanisms involved are still unknown. This study compared brain perfusion and clinical improvement during leucine or isoleucine supplementation. After randomization, 27 subjects with cirrhosis and HE received leucine or isoleucine supplements for one year. Brain single Photon Emission Computed Tomography (SPECT) and dynamic brain scintigraphy (DBS) were performed pretreatment and at 1, 8 and 12 months of supplementation. Brain perfusion was increased only in the isoleucine group at 8 months of treatment by both SPECT and DBS (p < 0.001 and p = 0.05, respectively) and by SPECT at the 12th month (p < 0.05). This was associated with hepatic encephalopathy improvement at 8 and 12 months (p = 0.008 and 0.004, respectively), which was not observed in the leucine group (p = 0.313 and 0.055, respectively). Isoleucine supplementation achieved a better impact on brain perfusion restoration in HE.

Impact of previous episodes of hepatic encephalopathy on short-term brain function recovery after liver transplantation: a functional connectivity strength study

Neuropsychological studies have documented an incomplete reversal of pre-existing cognitive dysfunction in cirrhotic patients after liver transplantation (LT) and have found this is more severe in patients with hepatic encephalopathy (HE). In this study, we aimed to investigate the impact of prior HE episodes on post-transplantation brain function recovery. Resting-state functional magnetic resonance imaging data was collected from 30 healthy controls and 33 cirrhotic patients (HE, n = 15 and noHE, n = 18) before and one month after LT. Long- and short-range functional connectivity strength (FCS) analysis indicated that before transplantation both noHE and HE groups showed diffuse FCS abnormalities relative to healthy controls. For the noHE group, the abnormal FCS found before LT largely returned to normal levels after LT, except for in the cerebellum, precuneus, and orbital middle frontal gyrus. However, the abnormal FCS prior to LT was largely preserved in the HE group, including high-level cognition-related (frontal and parietal lobes) and vision-related areas (occipital lobe, cuneus, and precuneus). In addition, comparisons between HE and noHE groups revealed that weaker FCS in default mode network (DMN) in HE group persisted from pre- to post- LT. Correlation analysis showed that changes in FCS in the left postcentral and right middle frontal gyrus correlated with alterations in neuropsychological performance and ammonia levels. In conclusion, the findings in this study demonstrate potential adverse effects of pre-LT episode of HE on post-LT brain function recovery, and reveal that DMN may be the most affected brain region by HE episodes, which can't be reversed by LT.

The genotypic and phenotypic spectrum of MTO1 deficiency

BACKGROUND

Mitochondrial diseases, a group of multi-systemic disorders often characterized by tissue-specific phenotypes, are usually progressive and fatal disorders resulting from defects in oxidative phosphorylation. MTO1 (Mitochondrial tRNA Translation Optimization 1), an evolutionarily conserved protein expressed in high-energy demand tissues has been linked to human early-onset combined oxidative phosphorylation deficiency associated with hypertrophic cardiomyopathy, often referred to as combined oxidative phosphorylation deficiency-10 (COXPD10).

MATERIAL AND METHODS

Thirty five cases of MTO1 deficiency were identified and reviewed through international collaboration. The cases of two female siblings, who presented at 1 and 2years of life with seizures, global developmental delay, hypotonia, elevated lactate and complex I and IV deficiency on muscle biopsy but without cardiomyopathy, are presented in detail.

RESULTS

For the description of phenotypic features, the denominator varies as the literature was insufficient to allow for complete ascertainment of all data for the 35 cases. An extensive review of all known MTO1 deficiency cases revealed the most common features at presentation to be lactic acidosis (LA) (21/34; 62% cases) and hypertrophic cardiomyopathy (15/34; 44% cases). Eventually lactic acidosis and hypertrophic cardiomyopathy are described in 35/35 (100%) and 27/34 (79%) of patients with MTO1 deficiency, respectively; with global developmental delay/intellectual disability present in 28/29 (97%), feeding difficulties in 17/35 (49%), failure to thrive in 12/35 (34%), seizures in 12/35 (34%), optic atrophy in 11/21 (52%) and ataxia in 7/34 (21%). There are 19 different pathogenic MTO1 variants identified in these 35 cases: one splice-site, 3 frameshift and 15 missense variants. None have bi-allelic variants that completely inactivate MTO1; however, patients where one variant is truncating (i.e. frameshift) while the second one is a missense appear to have a more severe, even fatal, phenotype. These data suggest that complete loss of MTO1 is not viable. A ketogenic diet may have exerted a favourable effect on seizures in 2/5 patients.

CONCLUSION

MTO1 deficiency is lethal in some but not all cases, and a genotype-phenotype relation is suggested. Aside from lactic acidosis and cardiomyopathy, developmental delay and other phenotypic features affecting multiple organ systems are often present in these patients, suggesting a broader spectrum than hitherto reported. The diagnosis should be suspected on clinical features and the presence of markers of mitochondrial dysfunction in body fluids, especially low residual complex I, III and IV activity in muscle. Molecular confirmation is required and targeted genomic testing may be the most efficient approach. Although subjective clinical improvement was observed in a small number of patients on therapies such as ketogenic diet and dichloroacetate, no evidence-based effective therapy exists.

Portacaval shunting causes differential mitochondrial superoxide production in brain regions

The portacaval shunting (PCS) prevents portal hypertension and recurrent bleeding of esophageal varices. On the other hand, it can induce chronic hyperammonemia and is considered to be the best model of mild hepatic encephalopathy (HE). Pathogenic mechanisms of HE and dysfunction of the brain in hyperammonemia are not fully elucidated, but it was originally suggested that the pathogenetic defect causes destruction of antioxidant defense which leads to an increase in the production of reactive oxygen species (ROS) and the occurrence of oxidative stress. In order to gain insight into the pathogenic mechanisms of HE in the brain tissue, we investigated the effects of PCS in rats on free radicals production and activity levels of antioxidant and prooxidant enzymes in mitochondria isolated from different brain areas. We found that O₂^·- production, activities of Mn-superoxide dismutase (Mn-SOD), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione transferase (GT), nitric oxide synthase (NOS), and levels of carbonylated proteins differed between the four brain regions both in the amount and response to PCS. In PCS rats, Mn-SOD activity in the cerebellum was significantly decreased, and remained unchanged in the neocortex, hippocampus and striatum compared with that in sham-operated animals. Among the four brain regions in control rats, the levels of the carbonyl groups in mitochondrial proteins were maximal in the cerebellum. 4 weeks after PCS, the content of carbonylated proteins were higher only in mitochondria of this brain region. Under control conditions, O₂^·- production by submitochondrial particles in the cerebellum was significantly higher than in other brain regions, but was significantly increased in each brain region from PCS animals. Indeed, the production of O₂^·- by submitochondrial particles correlated with mitochondrial ammonia levels in the four brain regions of control and PCS-animals. These findings are the first to suggest that in vivo levels of ammonia in the brain directly affect the rate of mitochondrial O₂^·- production.

Portal systemic shunt between the hepatic portal vein and right renal vein in a patient with multifocal hepatocellular carcinoma: Case report

Portal hypertension is a clinical syndrome characterized by the development of collateral circulation and portosystemic shunts, as well as ascites and hepatic encephalopathy. We present the case of a large portosystemic shunt between the hepatic portal vein and aneurysmal right renal vein in a cirrhotic 64-year-old man with thrombosis of the portal vein and hepatocellular carcinoma. This is a very rare clinical manifestation which, to our knowledge, has been described only once previously in the literature. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:524-527, 2017.

Altered dynamic functional connectivity in the default mode network in patients with cirrhosis and minimal hepatic encephalopathy

PURPOSE

Abnormal brain intrinsic functional connectivity (FC) has been documented in minimal hepatic encephalopathy (MHE) by static connectivity analysis. However, changes in dynamic FC (dFC) remain unknown. We aimed to identify altered dFC within the default mode network (DMN) associated with MHE.

METHODS

Resting-state functional MRI data were acquired from 20 cirrhotic patients with MHE and 24 healthy controls. DMN seed regions were defined using seed-based FC analysis (centered on the posterior cingulate cortex (PCC)). Dynamic FC architecture was calculated using a sliding time-window method. K-means clustering (number of clusters = 2-4) was applied to estimate FC states.

RESULTS

When the number of clusters was 2, MHE patients presented weaker connectivity strengths compared with controls in states 1 and 2. In state 1, decreased FC strength was found between the PCC/precuneus (PCUN) and right medial temporal lobe (MTL)/bilateral lateral temporal cortex (LTC); left inferior parietal lobule (IPL) and right MTL/left LTC; right IPL and right MTL/bilateral LTC; right MTL and right LTC; and medial prefrontal cortex (MPFC) and right MTL/bilateral LTC. In state 2, reduced FC strength was observed between the PCC/PCUN and bilateral MTL/bilateral LTC; left IPL and left MTL/bilateral LTC/MPFC; and left LTC and right LTC. Altered connectivities from state 1 were correlated with patient cognitive performance. Similar findings were observed when the number of clusters was set to 3 or 4.

CONCLUSION

Aberrant dynamic DMN connectivity is an additional characteristic of MHE. Dynamic connectivity analysis offers a novel paradigm for understanding MHE-related mechanisms.

Hybrid Surgery for Portosystemic Encephalopathy in a Patient with Liver Cirrhosis: a case report

Regarding the treatment for a portosystemic shunt, surgical or interventional radiological closure of the shunt was established. Interventional radiology including balloon-occluded retrograde transvenous obliteration can worsen portal hypertension and create a large thrombus close to the major venous system in the case of a huge portosystemic shunt. In contrast, it is also difficult to treat some cases through surgery alone when huge complicated shunts exist very deep in the body. Herein, we report a successful case of surgical shunt ligation for portosystemic encephalopathy in a hybrid operation room that enabled intraoperative angiography and computed tomography. A 62-year-old woman with chronic hepatitis C was referred to our hospital due to high levels of serum ammonia and hepatic encephalopathy. She had a massive, complicated portosystemic shunt from the inferior mesenteric vein to the left renal vein but did not have esophageal or gastric varices. It was difficult to occlude the portosystemic shunt by interventional radiologic techniques because the shunt had an extremely large amount of blood flow and many collateral routes. We performed the shunt ligation in the hybrid operation room. Intraoperative angiography provided detailed information about the portosystemic shunt, such as direction or volume of blood flow and collateral routes in real time. Her encephalopathy disappeared completely and she remains healthy with improved liver functional reserve to date. In conclusion, this is a successful case of a hybrid operation for an extremely large and complicated portosystemic shunt, providing for intraoperative angiography as a safe and reliable surgical treatment for portosystemic encephalopathy in patients with liver cirrhosis.

The PHES battery does not detect all cirrhotic patients with early neurological deficits, which are different in different patients

Background and aims

The psychometric hepatic encephalopathy score (PHES) is the “gold standard” for minimal hepatic encephalopathy (MHE) diagnosis. Some reports suggest that some cirrhotic patients “without” MHE according to PHES show neurological deficits and other reports that neurological alterations are not homogeneous in all cirrhotic patients. This work aimed to assess whether: 1) a relevant proportion of cirrhotic patients show neurological deficits not detected by PHES; 2) cirrhotic patients with mild neurological deficits are a homogeneous population or may be classified in sub-groups according to specific deficits.

Methods

Cirrhotic patients “without” (n = 56) or “with” MHE (n = 41) according to PHES and controls (n = 52) performed psychometric tests assessing attention, concentration, mental processing speed, working memory and bimanual and visuomotor coordination. Heterogeneity of neurological alterations was analysed using Hierarchical Clustering Analysis.

Results

PHES classified as “with” MHE 42% of patients. Around 40% of patients “without” MHE according to PHES fail two psychometric tests. Oral SDMT, d2, bimanual and visuo-motor coordination tests are failed by 54, 51, 51 and 43% of patients, respectively. The earliest neurological alterations are different for different patients. Hierarchical clustering analysis shows that patients “without” MHE according to PHES may be classified in clusters according to the tests failed. In some patients coordination impairment appear before cognitive impairment while in others concentration and attention deficits appear before.

Conclusions

PHES is not sensitive enough to detect early neurological alterations in a relevant proportion of cirrhotic patients. Oral SDMT, d2 and bimanual and visuo-motor coordination tests are more sensitive. The earliest neurological alterations are different in different cirrhotic patients. These data also have relevant clinical implications. Patients classified as “without MHE” by PHES belonging to clusters 3 and 4 in our study have a high risk of suffering clinical complications, including overt HE and must be diagnosed and clinically followed.

Qualifying and quantifying minimal hepatic encephalopathy

Minimal hepatic encephalopathy is the term applied to the neuropsychiatric status of patients with cirrhosis who are unimpaired on clinical examination but show alterations in neuropsychological tests exploring psychomotor speed/executive function and/or in neurophysiological variables. There is no gold standard for the diagnosis of this syndrome. As these patients have, by definition, no recognizable clinical features of brain dysfunction, the primary prerequisite for the diagnosis is careful exclusion of clinical symptoms and signs. A large number of psychometric tests/test systems have been evaluated in this patient group. Of these the best known and validated is the Portal Systemic Hepatic Encephalopathy Score (PHES) derived from a test battery of five paper and pencil tests; normative reference data are available in several countries. The electroencephalogram (EEG) has been used to diagnose hepatic encephalopathy since the 1950s but, once popular, the technology is not as accessible now as it once was. The performance characteristics of the EEG are critically dependent on the type of analysis undertaken; spectral analysis has better performance characteristics than visual analysis; evolving analytical techniques may provide better diagnostic information while the advent of portable wireless headsets may facilitate more widespread use. A large number of other diagnostic tools have been validated for the diagnosis of minimal hepatic encephalopathy including Critical Flicker Frequency, the Inhibitory Control Test, the Stroop test, the Scan package and the Continuous Reaction Time; each has its pros and cons; strengths and weaknesses; protagonists and detractors. Recent AASLD/EASL Practice Guidelines suggest that the diagnosis of minimal hepatic encephalopathy should be based on the PHES test together with one of the validated alternative techniques or the EEG. Minimal hepatic encephalopathy has a detrimental effect on the well-being of patients and their care-givers. It responds well to treatment with resolution of test abnormalities and the associated detrimental effects on quality of life, liver-related mortality and morbidity. Patients will only benefit in this way if they can be effectively diagnosed. Corporate efforts and consensus agreements are needed to develop effective diagnostic algorithms.

Artesunate restores spatial learning of rats with hepatic encephalopathy by inhibiting ammonia-induced oxidative damage in neurons and dysfunction of glutamate signaling in astroglial cells

BACKGROUND

Artesunate (ART) is an antimalarial drug with potential anti-inflammatory effect. This study aimed to explore the potential protective role of ART in hepatic encephalopathy (HE), involving its function against ammonia toxicity.

METHODS

HE rats were induced by the administration of thioacetamide (TAA, 300mg/kg/day). Spatial learning ability was tested in both Morris water and eight-arm radial maze. Rat cerebellar granule neurons (CGNs) were prepared for ammonia treatment in vitro, in line with SH-SY5Y and C6 cells. ART was administrated at 50 or 100mg/kg/day in vivo or added at 50 or 100μM in vitro. Oxidative damages were evaluated by the changes of cell viability, reactive oxygen species (ROS) levels and glutathione (GSH) content, while glutamate uptake and release, and the activities of glutamine synthetase (GS) and Na⁺K⁺-ATPase were measured to indicate the dysfunction of glutamate signaling.

RESULTS

Decreased escape latency and increased numbers of working errors were observed in TAA-induced HE rats, which could be significantly restored by ART at a dosage-dependent manner. Decreased cell viability and GSH content and increased ROS accumulation were detected in ammonia-treated SH-SY5Y and CGNs, while ammonia-treated C6 cells showed reduced glutamate uptake, increased glutamate release, and decrease of GSH content, GS and Na⁺K⁺-ATPase activity. In contrast, ART, especially at 100μM, strongly reversed all changes induced by ammonia, showing a similar dosage-dependent manner in vitro.

CONCLUSION

This study revealed a new neuroprotective role of ART in the pathogenesis of HE, by protecting neurons and astroglial cells from ammonia-induced damages and dysfunctions.

Intracortical inhibitory and excitatory circuits in subjects with minimal hepatic encephalopathy: a TMS study

Minimal hepatic encephalopathy (MHE) is the earliest form of hepatic encephalopathy (HE) and affects up to 80 % of patients with liver cirrhosis. By definition, MHE is characterized by psychomotor slowing and subtle cognitive deficits,  but obvious clinical manifestations are lacking. Given its covert nature, MHE is often underdiagnosed. This study was aimed at detecting neurophysiological changes, as assessed by means of transcranial magnetic stimulation (TMS), involved in the early pathogenesis of the HE. We investigated motor cortex excitability in 15 patients with MHE and in 15 age-matched age-matched cirrhotic patients without MHE; the resting motor threshold, the short-interval intracortical inhibition (SICI) and the intracortical facilitation (ICF) were examined. Paired-pulse TMS revealed significant increased SICI and reduced ICF in the patients with MHE. These findings may reflect abnormalities in intrinsic brain activity and altered organization of functional connectivity networks. In particular, the results suggest a shift in the balance between intracortical inhibitory and excitatory mechanisms towards a net increase of inhibitory neurotransmission. Together with other neurophysiological (in particular EEG) and neuroimaging techniques, TMS may thus provide early markers of cerebral dysfunction in cirrhotic patients with MHE.

Vigilance and wake EEG architecture in simulated hyperammonaemia: a pilot study on the effects of L-Ornithine-L-Aspartate (LOLA) and caffeine

Hyperammonaemia/mild hepatic encephalopathy (HE) can be simulated by the oral administration of a so-called amino acid challenge (AAC). This study sought to assess the effects of the AAC alone and in combination with either ammonia-lowering [L-ornithine-L-aspartate (LOLA)] or vigilance-enhancing medication (caffeine). Six patients with cirrhosis (5 males; 61.3 ± 9.2 years; 5 Child A, 1 Child B) and six healthy volunteers (5 males; 49.8 ± 10.6 years) were studied between 08:00 and 19:00 on Monday of three consecutive weeks. The following indices were obtained: hourly capillary ammonia, hourly subjective sleepiness, paper & pencil/computerized psychometry and wake electroencephalography (EEG) at 12:00, i.e. at the time of the maximum expected effect of the AAC.

RESULTS

On average, patients had worse neuropsychological performance and slower EEG than healthy volunteers in all conditions but differences did not reach significance. In healthy volunteers, the post-AAC increase in capillary ammonia levels was contained by both the administration of LOLA and of caffeine (significant differences between 10:00 and 14:00 h). The administration of caffeine also resulted in a reduction in subjective sleepiness and in the amplitude of the EEG on several frontal/temporal-occipital sites (p < 0.05; paired t-test). Changes in ammonia levels, subjective sleepiness and the EEG in the three conditions were less obvious in patients. In conclusion, both LOLA and caffeine contained the AAC-induced increase in capillary ammonia, especially in healthy volunteers. Caffeine also counteracted the AAC effects on sleepiness/EEG amplitude. The association of ammonia-lowering and vigilance-enhancing medication in the management of HE is worthy of further study.

Identifying minimal hepatic encephalopathy in cirrhotic patients by measuring spontaneous brain activity

It has been demonstrated that minimal hepatic encephalopathy (MHE) is associated with aberrant regional intrinsic brain activity in cirrhotic patients. However, few studies have investigated whether altered intrinsic brain activity can be used as a biomarker of MHE among cirrhotic patients. In this study, 36 cirrhotic patients (with MHE, n = 16; without MHE [NHE], n = 20) underwent resting-state functional magnetic resonance imaging (fMRI). Spontaneous brain activity was measured by examining the amplitude of low-frequency fluctuations (ALFF) in the fMRI signal. MHE was diagnosed based on the Psychometric Hepatic Encephalopathy Score (PHES). A two-sample t-test was used to determine the regions of interest (ROIs) in which ALFF differed significantly between the two groups; then, ALFF values within ROIs were selected as classification features. A linear discriminative analysis was used to differentiate MHE patients from NHE patients. The leave-one-out cross-validation method was used to estimate the performance of the classifier. The classification analysis was 80.6 % accurate (81.3 % sensitivity and 80.0 % specificity) in terms of distinguishing between the two groups. Six ROIs were identified as the most discriminative features, including the bilateral medial frontal cortex/anterior cingulate cortex, posterior cingulate cortex/precuneus, left precentral and postcentral gyrus, right lingual gyrus, middle frontal gyrus, and inferior/superior parietal lobule. The ALFF values within ROIs were correlated with PHES in cirrhotic patients. Our findings suggest that altered regional brain spontaneous activity is a useful biomarker for MHE detection among cirrhotic patients.

Lower values of handgrip strength and adductor pollicis muscle thickness are associated with hepatic encephalopathy manifestations in cirrhotic patients

Hepatic encephalopathy (HE) is a late complication of liver cirrhosis and is clearly associated with poor outcomes. Chronic liver insufficiency leads to progressive muscle wasting, impairing ammonia metabolism and thus increasing the risk for HE. Given the association between lean mass and adductor pollicis muscle thickness (APMT), it has been used to predict outcome and complications in many conditions, but not yet in cirrhotic patients. Therefore, this article aimed to study the association between HE manifestations and measures related to muscle mass and strength. This cross-sectional study included 54 cirrhotic outpatients with HE varying from subclinical to grade II according to the West-Haven criteria, who were submitted to neuropsychometric tests, electroencephalogram, brain Single Photon Emission Computed Tomography (SPECT), anthropometric measurements, handgrip strength (HGS) and dual energy X-ray absorptiometry exam (DXA). Multiple logistic regression analysis was performed to investigate the association between body composition measures and HE grade. Analysis of the area under the receiver operator characteristic (AUROC) curve revealed the values related to neurological manifestations (HE grades I and II). Reductions in APMT and HGS were associated with higher HE grades, suggesting a big impact caused by the loss of muscle mass and function on HE severity. The link between HE manifestations and anthropometric measures, namely APMT and HGS, point to a significant relation concerning skeletal muscles and the neurological impairment in this population.

Plasma Amino Acid Concentrations Predict Mortality in Patients with End-Stage Liver Disease

BACKGROUND

The liver plays a key role in amino acid metabolism. In former studies, a ratio between branched-chain and aromatic amino acids (Fischer's ratio) revealed associations with hepatic encephalopathy. Furthermore, low concentrations of branched-chain amino acids were linked to sarcopenia in literature. Encephalopathy and sarcopenia are known to dramatically worsen the prognosis. Aim of this study was to investigate a complex panel of plasma amino acids in the context of mortality in patients with end-stage liver disease.

METHODS

166 patients evaluated for orthotopic liver transplantation were included. 19 amino acids were measured from citrated plasma samples using mass spectrometry. We performed survival analysis for plasma amino acid constellations and examined the relationship to established mortality predictors.

RESULTS

33/166 (19.9%) patients died during follow-up. Lower values of valine (p<0.001), Fischer's ratio (p<0.001) and valine to phenylalanine ratio (p<0.001) and higher values of phenylalanine (p<0.05) and tyrosine (p<0.05) were significantly associated with mortality. When divided in three groups, the tertiles discriminated cumulative survival for valine (p = 0.016), phenylalanine (p = 0.024) and in particular for valine to phenylalanine ratio (p = 0.003) and Fischer's ratio (p = 0.005). Parameters were also significantly correlated with MELD and MELD-Na score.

CONCLUSIONS

Amino acids in plasma are valuable biomarkers to determine increased risk of mortality in patients with end-stage liver disease. In particular, valine concentrations and constellations composed of branched-chain and aromatic amino acids were strongly associated with prognosis. Due to their pathophysiological importance, the identified amino acids could be used to examine individual dietary recommendations to serve as potential therapeutic targets.

Modulation of GABAA receptors by neurosteroids. A new concept to improve cognitive and motor alterations in hepatic encephalopathy

Hepatic encephalopathy (HE) is a complex neuropsychiatric syndrome affecting patients with liver diseases, mainly those with liver cirrhosis. The mildest form of HE is minimal HE (MHE), with mild cognitive impairment, attention deficit, psychomotor slowing and impaired visuo-motor and bimanual coordination. MHE may progress to clinical HE with worsening of the neurological alterations which may lead to reduced consciousness and, in the worse cases, may progress to coma and death. HE affects several million people in the world and is a serious health, social and economic problem. There are no specific treatments for the neurological alterations in HE. The mechanisms underlying the cognitive and motor alterations in HE are beginning to be clarified in animal models. These studies have allowed to design and test in animal models of HE new therapeutic approaches which have successfully restored cognitive and motor function in rats with HE. In this article we review the evidences showing that.

A low-cost, user-friendly electroencephalographic recording system for the assessment of hepatic encephalopathy

Electroencephalography (EEG) is useful to objectively diagnose/grade hepatic encephalopathy (HE) across its spectrum of severity. However, it requires expensive equipment, and hepatogastroenterologists are generally unfamiliar with its acquisition/interpretation. Recent technological advances have led to the development of low-cost, user-friendly EEG systems, allowing EEG acquisition also in settings with limited neurophysiological experience. The aim of this study was to assess the relationship between EEG parameters obtained from a standard-EEG system and from a commercial, low-cost wireless headset (light-EEG) in patients with cirrhosis and varying degrees of HE. Seventy-two patients (58 males, 61 ± 9 years) underwent clinical evaluation, the Psychometric Hepatic Encephalopathy Score (PHES), and EEG recording with both systems. Automated EEG parameters were calculated on two derivations. Strong correlations were observed between automated parameters obtained from the two EEG systems. Bland and Altman analysis indicated that the two systems provided comparable automated parameters, and agreement between classifications (normal versus abnormal EEG) based on standard-EEG and light-EEG was good (0.6 < κ < 0.8). Automated parameters such as the mean dominant frequency obtained from the light-EEG correlated significantly with the Model for End-Stage Liver Disease score (r = -0.39, P < 0.05), fasting venous ammonia levels (r = -0.41, P < 0.01), and PHES (r = -0.49, P < 0.001). Finally, significant differences in light-EEG parameters were observed in patients with varying degrees of HE.

CONCLUSION

Reliable EEG parameters for HE diagnosing/grading can be obtained from a cheap, commercial, wireless headset; this may lead to more widespread use of this patient-independent tool both in routine liver practice and in the research setting. (

Machine Learning Classification of Cirrhotic Patients with and without Minimal Hepatic Encephalopathy Based on Regional Homogeneity of Intrinsic Brain Activity

Machine learning-based approaches play an important role in examining functional magnetic resonance imaging (fMRI) data in a multivariate manner and extracting features predictive of group membership. This study was performed to assess the potential for measuring brain intrinsic activity to identify minimal hepatic encephalopathy (MHE) in cirrhotic patients, using the support vector machine (SVM) method. Resting-state fMRI data were acquired in 16 cirrhotic patients with MHE and 19 cirrhotic patients without MHE. The regional homogeneity (ReHo) method was used to investigate the local synchrony of intrinsic brain activity. Psychometric Hepatic Encephalopathy Score (PHES) was used to define MHE condition. SVM-classifier was then applied using leave-one-out cross-validation, to determine the discriminative ReHo-map for MHE. The discrimination map highlights a set of regions, including the prefrontal cortex, anterior cingulate cortex, anterior insular cortex, inferior parietal lobule, precentral and postcentral gyri, superior and medial temporal cortices, and middle and inferior occipital gyri. The optimized discriminative model showed total accuracy of 82.9% and sensitivity of 81.3%. Our results suggested that a combination of the SVM approach and brain intrinsic activity measurement could be helpful for detection of MHE in cirrhotic patients.

Clinical and Neurologic Manifestation of Minimal Hepatic Encephalopathy and Overt Hepatic Encephalopathy

Hepatic encephalopathy (HE) shows a wide spectrum of neuropsychiatric manifestations. A combined effort with neuropsychological and psychometric evaluation has to be performed to recognize the syndrome, whereas minimal HE (MHE) is largely under-recognized. Subtle symptoms of MHE can only be diagnosed through specialized neuropsychiatric testing. Early diagnosis and treatment may drastically improve the quality of life for many cirrhotic patients. Further research to gain better insight into the pathophysiology and diagnostic accuracy of HE will help determine future management strategies.