Using saccades to diagnose covert hepatic encephalopathy

Covert Hepatic Encephalopathy (CHE), previously known as Minimal Hepatic Encephalopathy, is a subtle cognitive defect found in 30-70 % of cirrhosis patients. It has been linked to poor quality of life, impaired fitness to drive, and increased mortality: treatment is possible. Despite its clinical significance, diagnosis relies on psychometric tests that have proved unsuitable for use in a clinical setting. We investigated whether measurement of saccadic latency distributions might be a viable alternative. We collected data on 35 cirrhosis patients at Addenbrooke's Hospital, Cambridge, with no evidence of clinically overt encephalopathy, and 36 age-matched healthy controls. Performance on standard psychometric tests was evaluated to determine those patients with CHE as defined by the World Congress of Gastroenterology. We then compared visually-evoked saccades between those with CHE and those without, as well as reviewing blood test results and correlating saccadic latencies with biochemical parameters and prognostic scores. Cirrhosis patients have significantly longer median saccadic latencies than healthy controls. Those with CHE had significantly prolonged saccadic latencies when compared with those without CHE. Analysis of a cirrhosis patient's saccades can diagnose CHE with a sensitivity of 75 % and a specificity of 75 %. We concluded that analysis of a cirrhosis patient's saccadic latency distributions is a fast and objective measure that can be used as a diagnostic tool for CHE. This improved early diagnosis could direct avoidance of high-risk activities such as driving, and better inform treatment strategies.

Refining the ammonia hypothesis: a physiology-driven approach to the treatment of hepatic encephalopathy

Hepatic encephalopathy (HE) is one of the most important complications of cirrhosis and portal hypertension. Although the etiology is incompletely understood, it has been linked to ammonia directly and indirectly. Our goal is to review for the clinician the mechanisms behind hyperammonemia and the pathogenesis of HE to explain the rationale for its therapy. We reviewed articles collected through a search of MEDLINE/PubMed, Cochrane Database of Systematic Reviews, and Google Scholar between October 1, 1948, and December 8, 2014, and by a manual search of citations within retrieved articles. Search terms included hepatic encephalopathy, ammonia hypothesis, brain and ammonia, liver failure and ammonia, acute-on-chronic liver failure and ammonia, cirrhosis and ammonia, portosytemic shunt, ammonia and lactulose, rifaximin, zinc, and nutrition. Ammonia homeostatsis is a multiorgan process involving the liver, brain, kidneys, and muscle as well as the gastrointestinal tract. Indeed, hyperammonemia may be the first clue to poor functional reserves, malnutrition, and impending multiorgan dysfunction. Furthermore, the neuropathology of ammonia is critically linked to states of systemic inflammation and endotoxemia. Given the complex interplay among ammonia, inflammation, and other factors, ammonia levels have questionable utility in the staging of HE. The use of nonabsorbable disaccharides, antibiotics, and probiotics reduces gut ammoniagenesis and, in the case of antibiotics and probiotics, systemic inflammation. Nutritional support preserves urea cycle function and prevents wasting of skeletal muscle, a significant site of ammonia metabolism. Correction of hypokalemia, hypovolemia, and acidosis further assists in the reduction of ammonia production in the kidney. Finally, early and aggressive treatment of infection, avoidance of sedatives, and modification of portosystemic shunts are also helpful in reducing the neurocognitive effects of hyperammonemia. Refining the ammonia hypothesis to account for these other factors instructs a solid foundation for the effective treatment and prevention of hepatic encephalopathy.

Erythropoietin ameliorates the motor and cognitive function impairments in a rat model of hepatic cirrhosis

Hepatic encephalopathy (HE) is a serious consequence of hepatic cirrhosis (HC). Previous studies have demonstrated cognitive impairments in both clinical and animal experiments of HC. Some potential therapeutic agents have been used to alleviate the cognitive symptoms in the animal models of HC. In the current study, the possible effect of erythropoietin (ERY) as a potent neuroprotective agent on motor and cognitive impairments induced by HC has been studied. Male Wistar rats (180-200 g) underwent bile duct ligation (BDL) or sham surgery. Administration of ERY (5,000 IU/kg, i.p., daily for three days) was initiated 2 weeks after surgery and lasted for the next 28 days. Open field, rotarod, Morris water maze and passive avoidance learning was used to evaluate the motor and cognitive function of the animals. ANOVA and repeated measures ANOVA were used to analyze the data. p < 0.05 was considered statistically significant. BDL rats had an increased level of hepatic enzymes and bilirubin. Impairment of balance function by BDL was reversed by ERY. Spatial and passive avoidance learning impairments observed in BDL rats were also reversed by chronic administration of ERY. ERY can be offered as a potential neuroprotective agent in the treatment of patients with HC that manifest mental dysfunctions. Though further studies are needed to clarify the exact mechanisms, the neuroprotective properties of ERY against BDL impairments were demonstrated in the current study.

The predictors for continuous renal replacement therapy in liver transplant recipients

BACKGROUND

Acute renal failure (ARF) after liver transplantation requiring continuous renal replacement therapy (CRRT) adversely affects patient survival. We suggested that postoperative renal failure can be predicted if a clinically simple nomogram can be developed, thus selecting potential risk factors for preventive strategy.

METHODS

We retrospectively reviewed the medical records of 153 liver transplant recipients from January 2008 to December 2011 at Severance Hospital, Yonsei University Health System, in Seoul, Korea. There were 42 patients treated with CRRT (20 and 22 patients received transplants from living and deceased donors, respectively) and 115 were not. Univariate and stepwise logistic multivariate analyses were performed. A clinical nomogram to predict postoperative CRRT application was constructed and validated internally.

RESULTS

Hepatic encephalopathy (HEP; odds ratio OR, 5.47), deceased donor liver donations (OR, 3.47), Model for End-Stage Liver Disease (MELD) score (OR, 1.09), intraoperative blood loss (L; OR, 1.16), and tumor (hepatocellular carcinoma) as the indication for liver transplantation (OR, 0.11) were identified as independent predictive factors for postoperative CRRT on multivariate analysis. A clinical prediction model constructed for calculating the probability of CRRT post-transplantation was 1.7000 × HEP + [-4.5427 + 1.2440 × (deceased donor) + 0.0830 × (MELD score) + 0.000149 × the amount of intraoperative bleeding (L) - 2.1785 × tumor]. The validation set discriminated well with an area under the curve (AUC) of 0.90 (95% confidence interval, 0.85-0.95). The predicted and the actual probabilities were calibrated with the clinical nomogram.

CONCLUSIONS

We developed a predictive model of postoperative CRRT in liver transplantation patients. Perioperative strategies to modify these factors are needed.

Enhancement of functional connectivity, working memory and inhibitory control on multi-modal brain MR imaging with Rifaximin in Cirrhosis: implications for the gut-liver-brain axis

Minimal hepatic encephalopathy (MHE) impairs daily functioning in cirrhosis, but its functional brain impact is not completely understood. To evaluate the effect of rifaximin, a gut-specific antibiotic, on the gut-liver-brain axis in MHE.

HYPOTHESIS

Rifaximin will reduce endotoxemia, enhance cognition, increase activation during working memory(N-back) and reduce activation needed for inhibitory control tasks.

METHODS

Cirrhotics with MHE underwent baseline endotoxin and cognitive testing, then underwent fMRI, diffusion tensor imaging and MR spectroscopy(MRS). On fMRI, two tasks; N-back (outcome: correct responses) and inhibitory control tests(outcomes: lure inhibition) were performed. All procedures were repeated after 8 weeks of rifaximin. RESULTS were compared before/after rifaximin.

RESULTS

20 MHE patients (59.7 years) were included; sixteen completed pre/post-rifaximin scanning with 92% medication compliance. Pre-rifaximin patients had cognitive impairment. At trial-end, there was a significantly higher correct 2-back responses, ICT lure inhibitions and reduced endotoxemia(p = 0.002). This was accompanied by significantly higher activation from baseline in subcortical structures (thalamus, caudate, insula and hippocampus) and left parietal operculum (LPO) during N-back, decrease in fronto-parietal activation required for inhibiting lures, including LPO during ICT compared to baseline values. Connectivity studies in N-back showed significant shifts in linkages after therapy in fronto-parietal regions with a reduction in fractional anisotropy (FA) but not mean diffusivity (MD), and no change in MRS metabolites at the end of the trial. A significant improvement in cognition including working memory and inhibitory control, and fractional anisotropy without effect on MD or MRS, through modulation of fronto-parietal and subcortical activation and connectivity was seen after open-label rifaximin therapy in MHE.

Default mode network functional connectivity: a promising biomarker for diagnosing minimal hepatic encephalopathy: CONSORT-compliant article

To investigate the contribution of brain default mode network (DMN) in the early diagnosis of the minimal hepatic encephalopathy (MHE), the mildest form of HE from cirrhotic patients by using resting-state functional magnetic resonance imaging (rs-fMRI). This study was approved by the local ethical committee, and a written informed consent was obtained from each participant. A total of 103 cirrhotic patients (34 MHE, 69 non-HE) and 103 matched healthy controls underwent rs-fMRI scanning. The DMN correlation map was acquired by using unbiased seed-based functional connectivity analysis and compared among MHE patients, non-HE patients, and healthy controls with analysis of variance tests. Pearson correlation analysis was performed between the abnormal DMN connectivity and neuropsychological performances. Receiver operator characteristic (ROC) analysis was used to evaluate the contribution of DMN connectivity strength in the differential diagnosis between MHE and non-HE. Compared with the healthy controls, MHE and non-HE patients showed decreased DMN connectivity in medial prefrontal cortex (MPFC), left superior frontal gyrus (SFG), left temporal lobe, and bilateral middle temporal gyri (MTG). The MHE patients showed even more decreased connectivity in MPFC, left SFG, and right MTG when compared with non-HE patients. Pearson correlation analyses revealed that the decreased connectivity strength of some DMN regions correlated with patients' neuropsychological tests scores. Connectivity strength of the MPFC, right MTG, and left SFG could differentiate MHE from non-HE, of which the MPFC had the highest effectiveness (sensitivity = 81.5%, specificity = 70.4%). Cirrhotic patients had gradually reduced DMN functional connectivity from non-HE patients to MHE patients. DMN function, especially the MPFC, might be a useful imaging marker for differentiating MHE from cirrhotic patients.

Covert hepatic encephalopathy: Agreement and predictive validity of different indices

AIM: To investigate the agreement and prognostic value of different measures of covert hepatic encephalopathy (CHE).

METHODS: One-hundred-and-thirty-two cirrhotic outpatients underwent electroencephalography (EEG), paper-and-pencil psychometry (PHES) and critical flicker frequency, scored on the original/modified (CFFo/CFFm) thresholds. Eighty-four patients underwent Doppler-ultrasound to diagnose/exclude portal-systemic shunt. Seventy-nine were followed-up for 11 ± 7 mo in relation to the occurrence of hepatic encephalopathy (HE)-related hospitalisations.

RESULTS: On the day of study, 36% had grade I HE, 42% abnormal EEG, 33% abnormal PHES and 31/21% abnormal CFFo/CFFm. Significant associations were observed between combinations of test abnormalities; however, agreement was poor (Cohen’s κ < 0.4). The prevalence of EEG, PHES and CFFo/CFFm abnormalities was significantly higher in patients with grade I overt HE. The prevalence of EEG and CFFm abnormalities was higher in patients with shunt. The prevalence of EEG abnormalities was significantly higher in patients with a history of HE. During follow-up, 10 patients died, 10 were transplanted and 29 had HE-related hospitalisations. Grade I HE (P = 0.004), abnormal EEG (P = 0.008) and abnormal PHES (P = 0.04) at baseline all predicted the subsequent occurrence of HE; CFF did not.

CONCLUSION: CHE diagnosis probably requires a combination of clinical, neurophysiological and neuropsychological indices.

Embolization of splenorenal shunt associated to portal vein thrombosis and hepatic encephalopathy

Hepatic encephalopathy (HE) is a cognitive disturbance characterized by neuropsychiatric alterations. It occurs in acute and chronic hepatic disease and also in patients with portosystemic shunts. The presence of these portosystemic shunts allows the passage of nitrogenous substances from the intestines through systemic veins without liver depuration. Therefore, the embolization of these shunts has been performed to control HE manifestations, but the presence of portal vein thrombosis is considered a contraindication. In this presentation we show a cirrhotic patient with severe HE and portal vein thrombosis who was submitted to embolization of a large portosystemic shunt. Case report: a 57 years-old cirrhotic patient who had been hospitalized many times for persistent HE and hepatic coma, even without precipitant factors. She had a wide portosystemic shunt and also portal vein thrombosis. The abdominal angiography confirmed the splenorenal shunt and showed other shunts. The larger shunt was embolized through placement of microcoils, and the patient had no recurrence of overt HE. There was a little increase of esophageal and gastric varices, but no endoscopic treatment was needed. Since portosystemic shunts are frequent causes of recurrent HE in cirrhotic patients, portal vein thrombosis should be considered a relative contraindication to perform a shunt embolization. However, in particular cases with many shunts and severe HE, we found that one of these shunts can be safely embolized and this procedure can be sufficient to obtain a good HE recovery. In conclusion, we reported a case of persistent HE due to a wide portosystemic shunt associated with portal vein thrombosis. As the patient had other shunts, she was successfully treated by embolization of the larger shunt.

Non invasive blood flow measurement in cerebellum detects minimal hepatic encephalopathy earlier than psychometric tests

AIM: To assess whether non invasive blood flow measurement by arterial spin labeling in several brain regions detects minimal hepatic encephalopathy.

METHODS: Blood flow (BF) was analyzed by arterial spin labeling (ASL) in different brain areas of 14 controls, 24 cirrhotic patients without and 16 cirrhotic patients with minimal hepatic encephalopathy (MHE). Images were collected using a 3 Tesla MR scanner (Achieva 3T-TX, Philips, Netherlands). Pulsed ASL was performed. Patients showing MHE were detected using the battery Psychometric Hepatic Encephalopathy Score (PHES) consisting of five tests. Different cognitive and motor functions were also assessed: alterations in selective attention were evaluated using the Stroop test. Patients and controls also performed visuo-motor and bimanual coordination tests. Several biochemical parameters were measured: serum pro-inflammatory interleukins (IL-6 and IL-18), 3-nitrotyrosine, cGMP and nitrates+nitrites in plasma, and blood ammonia. Bivariate correlations were evaluated.

RESULTS: In patients with MHE, BF was increased in cerebellar hemisphere (P = 0.03) and vermis (P = 0.012) and reduced in occipital lobe (P = 0.017). BF in cerebellar hemisphere was also increased in patients without MHE (P = 0.02). Bimanual coordination was impaired in patients without MHE (P = 0.05) and much more in patients with MHE (P < 0.0001). Visuo-motor coordination was impaired only in patients with MHE (P < 0.0001). Attention was slightly affected in patients without MHE and more strongly in patients with MHE (P < 0.0001). BF in cerebellar hemisphere and vermis correlated with performance in most tests of PHES [(number connection tests A (NCT-A), B (NCT-B)and line tracing test] and in the congruent task of Stroop test. BF in frontal lobe correlated with NCT-A. Performance in bimanual and visuomotor coordination tests correlated only with BF in cerebellar hemisphere. BF in occipital lobe correlates with performance in the PHES battery and with CFF. BF in cerebellar hemisphere correlates with plasma cGMP and nitric oxide (NO) metabolites. BF in vermis cerebellar also correlates with NO metabolites and with 3-nitrotyrosine. IL-18 in plasma correlates with BF in thalamus and occipital lobe.

CONCLUSION: Non invasive BF determination in cerebellum using ASL may detect MHE earlier than the PHES. Altered NO-cGMP pathway seems to be associated to altered BF in cerebellum.

Transjugular intrahepatic portosystemic shunt for Budd-Chiari syndrome: techniques, indications and results on 51 Chinese patients from a single centre

BACKGROUND & AIMS

In Western countries, transjugular intrahepatic portosytemic shunt (TIPS) is widely applied for the treatment of Budd-Chiari syndrome (BCS). However, the outcome of Chinese BCS patients treated with TIPS is extremely limited. Furthermore, the timing of conversion from percutaneous recanalization to TIPS remains uncertain.

METHODS

All consecutive BCS patients treated with TIPS between December 2004 and June 2012 were included. Patients were classified as the early and converted TIPS groups. Indications, TIPS-related complications, post-TIPS hepatic encephalopathy, shunt dysfunction and death were reported.

RESULTS

Of 51 patients included, 39 underwent percutaneous recanalization for 1024 days (0-4574) before TIPS. Early TIPS group (n = 19) has a shorter history of BCS and a lower proportion of prior percutaneous recanalization than converted TIPS group (n = 32). Main indications were diffuse obstruction of three HVs (n = 12), liver failure (n = 2), liver function deterioration (n = 8), refractory ascites (n = 10) and variceal bleeding (n = 19). Procedure-related intraperitoneal bleeding was reversible in three patients. The cumulative 1-year rate of being free of first episode of post-TIPS hepatic encephalopathy and shunt dysfunction was 78.38 and 61.69% respectively. The cumulative 1-, 2-, and 3-year survival rates were 83.82, 81.20 and 76.93% respectively. BCS-TIPS score, but not Child-Pugh, MELD, Clichy or Rotterdam score, could predict the survival. Age, total bilirubin and inferior vena cava thrombosis were also significantly associated with overall survival. Survival was similar between early and converted TIPS groups.

CONCLUSIONS

TIPS can achieve an excellent survival in Chinese patients in whom percutaneous recanalization is ineffective or inappropriate. BCS-TIPS score could effectively predict these patients' survival.

Effect of renal function impairment on the mortality of cirrhotic patients with hepatic encephalopathy: a population-based 3-year follow-up study

Kidney is an important organ to clear neurotoxic substance in circulation. However, it is still unknown about the effect of renal function impairment (RFI) on the mortality of cirrhotic patients with hepatic encephalopathy (HE). We used the Taiwan National Health Insurance Database to identify 4932 cirrhotic patients with HE, hospitalized between January 1, 2007 and December 31, 2007. The enrolled patients were followed up individually for 3 years to identify their 3-year mortalities. There were 411 (8.3%) patients with RFI and 4521 (91.7%) patients without RFI. The adjusted hazard ratio (HR) of RFI for 3-year mortality was 2.03 (95% CI, 1.82-2.27). In RFI group, there were 157 (38.2%) patients with acute renal failure (ARF), 61 (14.8%) with hepatorenal syndrome (HRS), 93 (22.6%) with chronic kidney disease (CKD), and 100 (24.3%) with end-stage renal disease (ESRD). Compared with the non-RFI group, the adjusted HR of ARF for 3-year mortality was 2.57 (95% CI, 2.17-3.06), CKD 1.93 (95% CI, 1.55-2.40), ESRD 1.26 (95% CI, 1.01-1.57), and HRS 3.58 (95% CI, 2.78-4.63). Among ESRD patients, there were 99 patients receiving hemodialysis regularly. Compared with the CKD group, the adjusted HR of ESRD with hemodialysis for 3-year mortality was 0.664 (95% CI, 0.466-0.945). RFI increased the 3-year mortality of cirrhotic patients with HE, especially ARF and HRS. HE patients with ESRD receiving hemodialysis had better 3-year survival rate than those with CKD.

Resting-state functional magnetic resonance imaging in hepatic encephalopathy: current status and perspectives

Hepatic encephalopathy (HE) is a neuropsychiatric syndrome which develops in patients with severe liver diseases and/or portal-systemic shunting. Minimal HE, the earliest manifestation of HE, has drawn increasing attention in the last decade. Minimal HE is associated with a series of brain functional changes, such as attention, working memory, and so on. Blood oxygen level dependent (BOLD) functional MRI (fMRI), especially resting-state fMRI has been used to explore the brain functional changes of HE, yielding important insights for understanding pathophysiological mechanisms and functional reorganization of HE. This paper briefly reviews the principles of BOLD fMRI, potential applications of resting-state fMRI with advanced post-processing algorithms such as regional homogeneity, amplitude of low frequency fluctuation, functional connectivity and future research perspective in this field.

Aberrant interhemispheric functional coordination in patients with HBV-related cirrhosis and minimal hepatic encephalopathy

Aberrant brain functional connectivity has been considered as the important mechanism underlying minimal hepatic encephalopathy (MHE); however, little is known about the change in interhemispheric connection in MHE patients. Twenty patients with HBV-related cirrhosis and MHE and 15 healthy controls were included in this study and underwent the resting-state fMRI scanning and diffusion tensor imaging. The functional connectivity between symmetric interhemispheric voxels was computed by a technique called voxel-mirrored homotopic connectivity (VMHC), in which the time series for each voxel in one hemisphere was correlated with that of its homotopic voxel. Diffusion tensor imaging was conducted to measure the mean diffusivity (MD) and fractional anisotropy (FA) values in corpus callosum (CC). Compared with controls, MHE patients showed decreased regional VMHC in medial frontal gyrus, superior frontal gryus, anterior cingulate gyrus, inferior parietal lobule, postcentral gyrus, lingual gyrus, and middle occipital gyrus. MHE patients had significant decreased FA value in CC genu and CC splenium and increased MD value in CC genu. Pearson correlation analyses showed that the VMHC in anterior cingulate gyrus/medial frontal gyrus was correlated with FA/MD values of CC genu. These findings may suggest aberrant interhemispheric coordination in MHE and may provide new insight into the disease-related mechanisms.

[Clinical characteristics of patients with acute-on-chronic liver failure and splenomegaly]

OBJECTIVE

To observe the clinical characteristics and short-term survival of patients with splenomegaly and acute-on-chronic liver failure related to chronic HBV infection.

METHODS

Electronic medical records of patients with acute-on-chronic liver failure were collected to analyze the clinical parameters and 4-week survival of patients with or without splenomegaly.

RESULTS

Of the 149 patients enrolled, the overall 28-day mortality rate was 48.3%, which was lower in patients with enlarged spleen than those without (34.2% vs 54.1%, P=0.034). Compared with patients without splenomegaly, patients with splenomegaly had lower platelet counts (P=0.001), lower ALT levels (P=0.005) and lower PT-INR (P=0.010). Although the occurrence of hepatic encephalopathy was comparable between patients with or without splenomegaly, severe conditions were more frequent in those without splenomegaly. Hepatic encephalopathy grades, serum creatinine levels, neutrophil percentages over 70%, PT-INR and splenomegaly were independent factors associated with the 28-day survival, and this novel model was superior to model of end-stage of liver disease in predicting the 4-week survival (P=0.017).

CONCLUSION

Patients with splenomegaly that evolves into acute-on-chronic liver failure have unique clinical characteristics and further clinical observations are warranted.

Novel therapy for non-cirrhotic hyperammonemia due to a spontaneous splenorenal shunt

Spontaneous splenorenal shunts in the absence of cirrhosis have rarely been reported as a cause hyperammonemia with encephalopathy. Several closure techniques of such lesions have been described. Here we report a case of a patient with no history of liver disease who developed significant confusion. After an extensive workup, he was found to have hyperammonemia and encephalopathy due to formation of a spontaneous splenorenal shunt. There was no evidence of cirrhosis on biopsy or imaging and no portal hypertension when directly measured. The shunt was 18 mm and too large for embolization so the segment of the splenic vein between the portal vein and the shunt was occluded using an Amplatzer plug. Thus, the superior mesenteric flow was directed entirely to the liver. After interventional radiology closure of the shunt using this technique there was complete resolution of symptoms. The case represents the first report of a successful closure of splenorenal shunt via percutaneous embolization of the splenic vein with an amplatzer plug using a common femoral vein approach.

Classification of cirrhotic patients with or without minimal hepatic encephalopathy and healthy subjects using resting-state attention-related network analysis

Background

Attention deficit is an early and key characteristic of minimal hepatic encephalopathy (MHE) and has been used as indicator for MHE detection. The aim of this study is to classify the cirrhotic patients with or without MHE (NMHE) and healthy controls (HC) using the resting-state attention-related brain network analysis.

Methods and Findings

Resting-state fMRI was administrated to 20 MHE patients, 21 NMHE patients, and 17 HCs. Three attention-related networks, including dorsal attention network (DAN), ventral attention network (VAN), and default mode network (DMN), were obtained by independent component analysis. One-way analysis of covariance was performed to determine the regions of interest (ROIs) showing significant functional connectivity (FC) change. With FC strength of ROIs as indicators, Linear Discriminant Analysis (LDA) was conducted to differentiate MHE from HC or NMHE. Across three groups, significant FC differences were found within DAN (left superior/inferior parietal lobule and right inferior parietal lobule), VAN (right superior parietal lobule), and DMN (bilateral posterior cingulate gyrus and precuneus, and left inferior parietal lobule). With FC strength of ROIs from three networks as indicators, LDA yielded 94.6% classification accuracy between MHE and HC (100% sensitivity and 88.2% specificity) and 85.4% classification accuracy between MHE and NMHE (90.0% sensitivity and 81.0% specificity).

Conclusions

Our results suggest that the resting-state attention-related brain network analysis can be useful in classification of subjects with MHE, NMHE, and HC and may provide a new insight into MHE detection.

Optimal treatment of hepatic encephalopathy

Hepatic encephalopathy (HE) is a neuropsychiatric complication of acute or chronic liver disease with symptoms encompassing a continuum from mild confusion to coma. Both covert and overt HE have a significant impact on quality of life and healthcare related costs. The pathophysiology of HE is multifactorial and there is general consensus that ammonia and inflammation act synergistically to cause astrocyte swelling and cerebral edema. Current management strategies include the identification of precipitating factors and the initiation of pharmacologic therapies aimed at modulating intestinal flora and reducing levels of ammonia and other gut-derived toxins. Lactulose and rifaximin are two commonly used treatments for the management of HE. This article will review the optimal management of hepatic encephalopathy.

Ingestion of Lactobacillus strain reduces anxiety and improves cognitive function in the hyperammonemia rat

Evidence suggests that the hyperammonemia (HA)-induced neuroinflammation and alterations in the serotonin (5-HT) system may contribute to cognitive decline and anxiety disorder during hepatic encephalopathy (HE). Probiotics that maintain immune system homeostasis and regulate the 5-HT system may be potential treatment for HA-mediated neurological disorders in HE. In this study, we tested the efficacy of probiotic Lactobacillus helveticus strain NS8 in preventing cognitive decline and anxiety-like behavior in HA rats. Chronic HA was induced by intraperitoneal injection of ammonium acetate for four weeks in male Sprague-Dawley rats. HA rats were then given Lactobacillus helveticus strain NS8 (10(9) CFU mL(-1)) in drinking water as a daily supplementation. The Morris water maze task assessed cognitive function, and the elevated plus maze test evaluated anxiety-like behavior. Neuroinflammation was assessed by measuring the inflammatory markers: inducible nitric oxide synthase, prostaglandin E2, and interleukin-1 β in the brain. 5-HT system activity was evaluated by measuring 5-HT and its metabolite, 5-HIAA, and the 5-HT precursor, tryptophan. Probiotic treatment of HA rats significantly reduced the level of inflammatory markers, decreased 5-HT metabolism, restored cognitive function and improved anxiety-like behavior. These results indicate that probiotic L. helveticus strain NS8 is beneficial for the treatment of cognitive decline and anxiety-like behavior in HA rats.

Assessment of risk of complications in cirrhosis using portal thallium scans

AIM: To investigate the usefulness of a novel thallium scan shunt index for assessing portosystemic shunt-related cirrhotic complications.

METHODS: We enrolled 209 chronic hepatitis B-related cirrhosis patients. After rectal thallium instillation, radioactive isotope activity in the heart and liver was measured. The ratio of radiation uptake between the heart and the liver was calculated (the shunt index). This value indicates the degree of portosystemic circulation shunting. Blood tests, serum biochemistry tests, abdominal ultrasonography, gastroscopy and examination of clinical features such as the occurrence of varices, bleeding and hepatic encephalopathy were performed. Multivariate analysis was used to identify independent risk factors for complications. We compared the cumulative incidence rates of complications during the follow-up period.

RESULTS: The thallium scan shunt index was significantly higher in the decompensated liver cirrhosis group than in the compensated liver cirrhosis group (0.91 ± 0.39 vs 0.39 ± 0.32, P < 0.001). It was also higher in the varices group, the hepatic encephalopathy group, and the variceal bleeding group than in the control group (P < 0.001). Multivariate analysis showed that the index was an independent risk factor for predicting decompensated liver cirrhosis. When the cut-off value was 0.75, the shunt index had a sensitivity of 82.6%, a specificity of 84%, a positive predictive value of 61.5%, and a negative predictive value of 94.4% in diagnosing decompensated cirrhosis. When the shunt index was greater than 0.75, there was a significant increase in the number of decompensated events.

CONCLUSION: The thallium shunt index is a good predictor of cirrhosis-related complications.

Brainstem evoked response audiometry: an investigatory tool in detecting hepatic encephalopathy in decompensated chronic liver disease

It is estimated that globally there is a marked increase in liver disease with reports of rising morbidity and mortality, particularly in younger age groups. Brainstem auditory evoked potential (BAEP) was recorded in 60 decompensated chronic liver disease (DCLD) subjects who fulfilled the selection criteria and compared to 60 age and gender matched healthy subjects with normal liver functions. DCLD subjects were divided into two inter groups based on presence or absence of hepatic encephalopathy (HE). Group 1 comprises of 30 subjects of grade- I HE and Group 2 included 30 subjects without hepatic encephalopathy (NHE). Absolute and interpeak wave latencies were measured. Results were analysed by student independent t- test using SPSS software 11 version. Statistical significance was tested using P value. From the present study it can be concluded that the central nervous system is involved in liver cirrhosis evidenced by an abnormal BAEP latencies parameters. This shows that there may be progressive demyelination occurring along with axonal loss or dysfunction in liver cirrhosis HE. This study suggests that periodic evaluation of cirrhotic individuals to such test will help in monitoring the progress of encephalopathy. The prime goal of this study is early diagnosis and initiation of treatment before the onset of coma can reduce the fatality rate.

[Comparative effectiveness of different treatment methods of liver failure]

It was analyzed the results of treatment of 217 patients (139 men, 78 women) with chronic liver failure in case of liver cirrhosis of various etiology for study of degree of hepatic encephalopathyregression. All patients were divided into 3 groups. In the first group the drug therapy was used. In the second group additionallyplasma exchange was performed, in the third group - alsomolecular absorbent recirculating system was used (effectiveness of MARS-therapy).The results showed that the use of extracorporeal treatment techniques can effectively reduce the severity of hepatic encephalopathy in patients with liver cirrhosis. MARS-therapy improved the neurological status of patientsmore significantly in this case. It is considered that the inclusion of MARS-therapy in the combined treatment of patients leads to a significant reduction of hepatic encephalopathyseverity (1-2 points), in comparison with other methods of treatment.

Treatment of hyperammonemia in liver failure

PURPOSE OF REVIEW

Hyperammonemia is thought to be central in the pathophysiology of hepatic encephalopathy in patients suffering from liver failure. The purpose of this article is to explore existing treatment options that help lower ammonia levels in patients and alleviate symptoms of hepatic encephalopathy.

RECENT FINDINGS

There are two ways to approach modulating ammonia levels and its effect on the brain. The first targets ammonia levels itself and the second targets inflammation, which makes the brain susceptible to the deleterious effect of ammonia. Recent studies provide new evidence for the use of lactulose, probiotics and rifaximin, as well as closure of large portosystemic shunts in the treatment of hepatic encephalopathy.

SUMMARY

Over the past 20 years or so, many new approaches to treat hepatic encephalopathy have been developed based upon better understanding of interorgan ammonia metabolism. Reduction in ammonia can be achieved by targeting its production, absorption or elimination. This review will primarily focus on these strategies that reduce ammonia levels in liver failure patients.

Pathophysiology of cerebral oedema in acute liver failure

Cerebral oedema is a devastating consequence of acute liver failure (ALF) and may be associated with the development of intracranial hypertension and death. In ALF, some patients may develop cerebral oedema and increased intracranial pressure but progression to life-threatening intracranial hypertension is less frequent than previously described, complicating less than one third of cases who have proceeded to coma since the advent of improved clinical care. The rapid onset of encephalopathy may be dramatic with the development of asterixis, delirium, seizures and coma. Cytotoxic and vasogenic oedema mechanisms have been implicated with a preponderance of experimental data favouring a cytotoxic mechanism. Astrocyte swelling is the most consistent neuropathological finding in humans with ALF and ammonia plays a definitive role in the development of cytotoxic brain oedema. The mechanism(s) by which ammonia induces astrocyte swelling remains unclear but glutamine accumulation within astrocytes has led to the osmolyte hypothesis. Current evidence also supports an alternate ‘Trojan horse’ hypothesis, with glutamine as a carrier of ammonia into mitochondria, where its accumulation results in oxidative stress, energy failure and ultimately astrocyte swelling. Although a complete breakdown of the blood-brain barrier is not evident in human ALF, increased permeation to water and other small molecules such as ammonia has been demonstrated resulting from subtle alterations in the protein composition of paracellular tight junctions. At present, there is no fully efficacious therapy for cerebral oedema other than liver transplantation and this reflects our incomplete knowledge of the precise mechanisms underlying this process which remain largely unknown.

Abnormal baseline brain activity in patients with HBV-related cirrhosis without overt hepatic encephalopathy revealed by resting-state functional MRI

Neurocognitive dysfunction of varying degrees is common in patients with hepatitis B virus-related cirrhosis (HBV-RC) without overt hepatic encephalopathy (OHE). However, the neurobiological mechanisms underlying these dysfunctions are not well understood. We sought to identify changes in the neural activity of patients with HBV-RC without OHE in the resting state by using the amplitude of low-frequency fluctuation (ALFF) method and to determine whether these changes were related to impaired cognition. Resting-state functional MRI data from 30 patients with HBV-RC and 30 healthy controls matched for age, sex, and years of education were compared to determine any differences in the ALFF between the two groups. Cognition was measured with the psychometric hepatic encephalopathy score (PHES), and the relationship between these scores and ALFF variation was assessed. Compared with controls, patients showed widespread lower standardized ALFF (mALFF) values in visual association areas (bilateral lingual gyrus, middle occipital gyrus, and left inferior temporal gyrus), motor-related areas (bilateral precentral gyrus, paracentral lobule, and right postcentral gyrus), and the default mode network (bilateral cuneus/precuneus and inferior parietal lobule). Higher mALFF values were found in the bilateral orbital gyrus/rectal gyrus. In patients, mALFF values were significantly positive correlated with the PHES in the right middle occipital gyrus and bilateral precentral gyrus. Our findings of resting-state abnormalities in patients with HBV-RC without OHE suggest that neurocognitive dysfunction in patients with HBV-RC without OHE may be caused by abnormal neural activity in multiple brain regions.

Synergistic effects between CA1 mu opioid and dopamine D1-like receptors in impaired passive avoidance performance induced by hepatic encephalopathy in mice

BACKGROUND AND AIM

Numerous investigations have indicated that hepatic encephalopathy (HE) alters the levels of various neurotransmitters. However, comprehensive data regarding the effects of CA1 opioidergic and dopaminergic (DAergic) systems on HE-induced amnesia are still lacking.

METHODS

Following intra-dorsal hippocampal (CA1) injection of mu opioid and dopamine D1- and D2-like receptors antagonists in male mice, one-trial step-down and hole-board paradigms were used to assess memory and exploratory behaviors, respectively.

RESULTS

Our data demonstrated that HE impairs memory 24 days after bile duct ligation (BDL). Furthermore, while the higher dose of DA D1-like receptor antagonist (SCH23390, 0.5 μg/mouse) induced amnesia and anxiogenic-like behaviors, mu receptor antagonist (naloxone: 0.0125, 0.025 and 0.05 μg/mouse) and DA D2-like receptor antagonist (sulpiride: 0.0625, 0.125 and 0.25 μg/mouse) by themselves, could not exert an effect on memory performance in passive avoidance task. On the other hand, pre-test injection of all drugs reversed the HE-induced amnesia 24 days after BDL, while having no effect on exploratory behaviors. Pre-test co-administration of the subthreshold dose SCH23390 (0.25 μg/mouse) and sulpiride (0.0625 μg/mouse) or naloxone (0.0125 μg/mouse) could likewise reverse the BDL-induced amnesia. However, when the subthreshold sulpiride plus naloxone were co-administered, BDL-induced amnesia was not blocked.

CONCLUSIONS

Memory performance is impaired 24 days post BDL and CA1 mu opioid and DA D1-like receptors antagonist synergistic effects are likely involved in this phenomenon.

Liver-brain proinflammatory signalling in acute liver failure: role in the pathogenesis of hepatic encephalopathy and brain edema

A robust neuroinflammatory response characterized by microglial activation and increased brain production of pro-inflammatory cytokines is common in acute liver failure (ALF). Mechanisms proposed to explain the neuroinflammatory response in ALF include direct effects of systemically-derived proinflammatory cytokines and the effects of brain lactate accumulation on pro-inflammatory cytokine release from activated microglia. Cell culture studies reveal a positive synergistic effect of ammonia and pro-inflammatory cytokines on the expression of proteins involved in glutamate homeostasis and in oxidative/nitrosative stress. Proinflammatory cytokines have the capacity to alter blood-brain barrier (BBB) integrity and preliminary studies suggest that the presence of infection in ALF results in rupture of the BBB and vasogenic brain edema. Treatments currently under investigation that are effective in prevention of encephalopathy and brain edema in ALF which are aimed at reduction of neuroinflammation in ALF include mild hypothermia, albumin dialysis systems, N-acetyl cysteine and the antibiotic minocycline with potent anti-inflammatory actions that are distinct from its anti-microbial properties.

Oxidative stress: a systemic factor implicated in the pathogenesis of hepatic encephalopathy

Although ammonia is considered the main factor involved in the pathogenesis of hepatic encephalopathy (HE), it correlates well with the severity of HE in acute liver failure, but not in chronic liver disease. Oxidative stress is another factor believed to play a role in the pathogenesis of this syndrome; it represents an imbalance between the production and neutralization of reactive oxygen species, which leads to cellular dysfunction. In the setting of liver disease, oxidative stress represents a systemic phenomenon induced by several mechanisms: decreased antioxidant synthesis, increased systemic release of oxidant enzymes, generation of reactive oxygen species, and impaired neutrophil function. High ammonia concentrations induce cerebral oxidative stress, thus contributing to severe hepatic encephalopathy, as observed in acute liver failure. In chronic liver disease, significantly lower degrees of hyperammonemia (<500 μM) do not induce cerebral nor systemic oxidative stress. Data from both animal and human studies sustain that there is a synergistic effect between systemic oxidative stress, and ammonia that is implicated in the pathogenesis of hepatic encephalopathy.

Abnormal chloride homeostasis in the substancia nigra pars reticulata contributes to locomotor deficiency in a model of acute liver injury

BACKGROUND

Altered chloride homeostasis has been thought to be a risk factor for several brain disorders, while less attention has been paid to its role in liver disease. We aimed to analyze the involvement and possible mechanisms of altered chloride homeostasis of GABAergic neurons within the substantia nigra pars reticulata (SNr) in the motor deficit observed in a model of encephalopathy caused by acute liver failure, by using glutamic acid decarboxylase 67 - green fluorescent protein knock-in transgenic mice.

METHODS

Alterations in intracellular chloride concentration in GABAergic neurons within the SNr and changes in the expression of two dominant chloride homeostasis-regulating genes, KCC2 and NKCC1, were evaluated in mice with hypolocomotion due to hepatic encephalopathy (HE). The effects of pharmacological blockade and/or activation of KCC2 and NKCC1 functions with their specific inhibitors and/or activators on the motor activity were assessed.

RESULTS

In our mouse model of acute liver injury, chloride imaging indicated an increase in local intracellular chloride concentration in SNr GABAergic neurons. In addition, the mRNA and protein levels of KCC2 were reduced, particularly on neuronal cell membranes; in contrast, NKCC1 expression remained unaffected. Furthermore, blockage of KCC2 reduced motor activity in the normal mice and led to a further deteriorated hypolocomotion in HE mice. Blockade of NKCC1 was not able to normalize motor activity in mice with liver failure.

CONCLUSION

Our data suggest that altered chloride homeostasis is likely involved in the pathophysiology of hypolocomotion following HE. Drugs aimed at restoring normal chloride homeostasis would be a potential treatment for hepatic failure.

The effect of fractionated plasma separation and adsorption on cerebral amino acid metabolism and oxidative metabolism during acute liver failure

BACKGROUND & AIMS

Patients with acute liver failure have a disturbed amino acid metabolism and a compromised oxidative metabolism in the brain. A limited number of clinically neuroprotective interventions are available. This study aimed at assessing the effect of fractionated plasma separation and adsorption (FPSA), an extracorporeal liver support system, on cerebral amino acids and lactate to pyruvate ratio.

METHODS

Seven patients with acute liver failure and high risk of intracranial hypertension were included for cerebral microdialysis and intracranial pressure monitoring. Microdialysate, arterial blood, and venous blood from the jugular bulb were sampled, before and after an FPSA session, and the content of nineteen amino acids, lactate, and pyruvate was determined.

RESULTS

The total amino acid concentration in arterial plasma was not significantly reduced by FPSA (11.2 mM (3.0-26.0 mM) vs. 9.7 mM (2.7-13.6 mM); median with range). The total amino acid content in the microdialysate was 5.6 mM both before and after FPSA and no change in glutamine content was observed in plasma or microdialysate. The content of aromatic amino acids in arterial plasma, but not in microdialysate, was marginally reduced (p<0.05). Arterial lactate concentration and lactate to pyruvate ratio in the microdialysate did not change following FPSA.

CONCLUSIONS

One single treatment session with FPSA had a marginal effect on plasma amino acid composition. We found minimal changes in the amino acids content in the microdialysate, and the lactate to pyruvate ratio was unaffected.

Altered regional homogeneity in the development of minimal hepatic encephalopathy: a resting-state functional MRI study

Background

Little is known about how spontaneous brain activity progresses from non-hepatic encephalopathy (non-HE) to minimal HE (MHE). The purpose of this study was to evaluate the evolution pattern of spontaneous brain activities in cirrhotic patients using resting-state fMRI with a regional homogeneity (ReHo) method.

Methodology/Principal Findings

Resting-state fMRI data were acquired in 47 cirrhotic patients (minimal HE [MHE], n = 20, and non-HE, n = 27) and 25 age-and sex-matched healthy controls. The Kendall’s coefficient of concordance (KCC) was used to measure the regional homogeneity. The regional homogeneity maps were compared with ANOVA tests among MHE, non-HE, and healthy control groups and t-tests between each pair in a voxel-wise way. Correlation analyses were performed to explore the relationships between regional ReHo values and Child-Pugh scores, number connection test type A (NCT-A), digit symbol test (DST) scores, venous blood ammonia levels. Compared with healthy controls, both MHE and non-HE patients showed decreased ReHo in the bilateral frontal, parietal and temporal lobes and increased ReHo in the bilateral caudate. Compared with the non-HE, MHE patients showed decreased ReHo in the bilateral precuneus, cuneus and supplementary motor area (SMA). The NCT-A of cirrhotic patients negatively correlated with ReHo values in the precuneus, cuneus and lingual gyrus. DST scores positively correlated with ReHo values in the cuneus, precuneus and lingual gyrus, and negatively correlated with ReHo values in the bilateral caudate (P<0.05, AlphaSim corrected).

Conclusions/Significance

Diffused abnormal homogeneity of baseline brain activity was nonspecific for MHE, and only the progressively decreased ReHo in the SMA and the cuneus, especially for the latter, might be associated with the development of MHE. The ReHo analysis may be potentially valuable for detecting the development from non-HE to MHE.

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

BACKGROUND AND PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Structural and functional abnormalities of default mode network in minimal hepatic encephalopathy: a study combining DTI and fMRI

Background and Purpose

Live failure can cause brain edema and aberrant brain function in cirrhotic patients. In particular, decreased functional connectivity within the brain default-mode network (DMN) has been recently reported in overt hepatic encephalopathy (HE) patients. However, so far, little is known about the connectivity among the DMN in the minimal HE (MHE), the mildest form of HE. Here, we combined diffusion tensor imaging (DTI) and resting-state functional MRI (rs-fMRI) to test our hypothesis that both structural and functional connectivity within the DMN were disturbed in MHE.

Materials and Methods

Twenty MHE patients and 20 healthy controls participated in the study. We explored the changes of structural (path length, tracts count, fractional anisotropy [FA] and mean diffusivity [MD] derived from DTI tractography) and functional (temporal correlation coefficient derived from rs-fMRI) connectivity of the DMN in MHE patients. Pearson correlation analysis was performed between the structural/functional indices and venous blood ammonia levels/neuropsychological tests scores of patients. All thresholds were set at P<0.05, Bonferroni corrected.

Results

Compared to the healthy controls, MHE patients showed both decreased FA and increased MD in the tract connecting the posterior cingulate cortex/precuneus (PCC/PCUN) to left parahippocampal gyrus (PHG), and decreased functional connectivity between the PCC/PCUN and left PHG, and medial prefrontal cortex (MPFC). MD values of the tract connecting PCC/PCUN to the left PHG positively correlated to the ammonia levels, the temporal correlation coefficients between the PCC/PCUN and the MPFC showed positive correlation to the digital symbol tests scores of patients.

Conclusion

MHE patients have both disturbed structural and functional connectivity within the DMN. The decreased functional connectivity was also detected between some regions without abnormal structural connectivity, suggesting that the former may be more sensitive in detecting the early abnormalities of MHE. This study extends our understanding of the pathophysiology of MHE.

Cognitive evoked response potentials in patients with liver cirrhosis without diagnosis of minimal or overt hepatic encephalopathy. A pilot study

Liver cirrhosis is often accompanied by cognitive deficits called minimal hepatic encephalopathy (MHE) when it is observed to a moderate extent. In the present study, brain activity and cognitive functioning were examined in patients with liver cirrhosis without MHE or overt clinical hepatic encephalopathy. A battery of neuropsychological tests and event related potentials (ERPs) were used. Moreover, an additional n-back task was administered with two difficulty levels (1- and 2-back). This task was designed to engage cognitive processes of storage and manipulation of information in working memory. The participants have to decide whether the letter shown was the same as a target (congruence condition). No significant differences were found in the performance of either the neuropsychological tests or the n-back task. However, the expected effects of decreased performance as well as a decrease in P3 amplitude with difficulty level were identified. The interaction of group x congruence condition was also observed in the P2 component time window. These results may indicate group differences manifesting in early stages of information processing in working memory. It confirms that the patients whose neuropsychological performance is within the normal range can still reveal subtle changes in CNS functioning visible in ERP research. The study confirms the usability of the ERP method in diagnosis of neurocognitive functions in patients with liver cirrhosis, which seems to be more sensitive than neuropsychological tests.

A longitudinal systems biology analysis of lactulose withdrawal in hepatic encephalopathy

The pathogenesis of hepatic encephalopathy(HE) is unclear. However gut flora changes, inflammation and neuro-glial injury have been implicated. The aim was to evaluate factors that were associated with HE recurrence after lactulose withdrawal by analyzing the clinical phenotype, stool microbiome and systemic metabolome longitudinally. HE patients on a standard diet who were adherent on lactulose underwent characterization of their phenotype [cognition, inflammatory cytokines, in-vivo brain MR spectroscopy(MRS)], gut microbiome (stool Multitag Pyrosequencing) and metabolome (urine/serum ex-vivo MRS) analysis while on lactulose and on days 2, 14 and 30 post-withdrawal. Patients whose HE recurred post-withdrawal were compared to those without recurrence. We included seven men (53 ± 8 years) who were adherent on lactulose after a precipitated HE episode were included. HE recurred in three men 32 ± 6 days post-withdrawal. In-vivo brain MRS showed increased glutamine+glutamate (Glx) and decreased myoinositol with a reduction in stool Faecalibacterium spp., post-withdrawal. HE recurrence was predicted by poor baseline inhibitory control and block design performance and was associated with a shift of choline metabolism from tri-methylamine oxide formation towards the development of di-methylglycine, glycine and creatinine. This was accompanied by a mixed effect on the immune response (suppressed IL-10 and Th1/Th2/Th17 response). The correlation network showed Prevotella to be linked to improved cognition and decreased inflammation in patients without HE recurrence. We conclude that lactulose withdrawal results in worsening cognition, mixed inflammatory response effect, lowered stool Faecalibacterium and increase in MR-measurable brain Glx. HE recurrence post-lactulose withdrawal can be predicted by baseline cognitive performance and is accompanied by disrupted choline metabolism.

Selective impairments of resting-state networks in minimal hepatic encephalopathy

BACKGROUND

Minimal hepatic encephalopathy (MHE) is a neuro-cognitive dysfunction characterized by impairment in attention, vigilance and integrative functions, while the sensorimotor function was often unaffected. Little is known, so far, about the exact neuro-pathophysiological mechanisms of aberrant cognition function in this disease.

METHODOLOGY/PRINCIPAL FINDINGS

To investigate how the brain function is changed in MHE, we applied a resting-state fMRI approach with independent component analysis (ICA) to assess the differences of resting-state networks (RSNs) between MHE patients and healthy controls. Fourteen MHE patients and 14 age-and sex-matched healthy subjects underwent resting-state fMRI scans. ICA was used to identify six RSNs [dorsal attention network (DAN), default mode network (DMN), visual network (VN), auditory network (AN), sensorimotor network (SMN), self-referential network (SRN)] in each subject. Group maps of each RSN were compared between the MHE and healthy control groups. Pearson correlation analysis was performed between the RSNs functional connectivity (FC) and venous blood ammonia levels, and neuropsychological tests scores for all patients. Compared with the healthy controls, MHE patients showed significantly decreased FC in DAN, both decreased and increased FC in DMN, AN and VN. No significant differences were found in SRN and SMN between two groups. A relationship between FC and blood ammonia levels/neuropsychological tests scores were found in specific regions of RSNs, including middle and medial frontal gyrus, inferior parietal lobule, as well as anterior and posterior cingulate cortex/precuneus.

CONCLUSIONS/SIGNIFICANCE

MHE patients have selective impairments of RSNs intrinsic functional connectivity, with aberrant functional connectivity in DAN, DMN, VN, AN, and spared SMN and SRN. Our fMRI study might supply a novel way to understand the neuropathophysiological mechanism of cognition function changes in MHE.

Simultaneous combined balloon-occluded retrograde transvenous obliteration and partial splenic embolization for portosystemic shunts

PURPOSE

To evaluate the efficacy and safety of simultaneous combined balloon-occluded retrograde transvenous obliteration (B-RTO) and partial splenic embolization (PSE) for gastric varices and/or hepatic encephalopathy.

MATERIALS AND METHODS

B-RTO was performed in 19 consecutive patients with gastric varices and/or hepatic encephalopathy, of whom 10 received simultaneous combined B-RTO and PSE (group 1) and nine received B-RTO monotherapy (group 2). To evaluate the safety of these techniques, we analyzed 20 patients who received PSE monotherapy during the same period as a control group (group 3). Outcomes were retrospectively assessed.

RESULTS

No significant differences were observed in baseline characteristics among the three groups except for significantly lower platelet counts and larger spleen volumes in group 3. In all cases in groups 1 and 2, gastric varices disappeared and hepatic encephalopathy improved after treatment. Procedure times were not significantly different between groups 1 and 2 (P = .7435). In group 1, the volume of sclerosing agent required for B-RTO was significantly lower (P = .0355) and exacerbation of esophageal varices was significantly less frequent (P = .0146) than in group 2. Few serious complications occurred in patients who received combined therapy.

CONCLUSIONS

This study indicates that concomitant PSE may help diminish the increase in portal venous pressure after B-RTO for portosystemic shunts, and may allow a reduction in the volume of hazardous sclerosing agent used. It is worth evaluating the efficacy of simultaneous B-RTO and PSE in a prospective study.

Abnormal baseline brain activity in low-grade hepatic encephalopathy: a resting-state fMRI study

Resting-state functional magnetic resonance imaging (fMRI) has been used to detect the alterations of spontaneous neuronal activity in various neuropsychiatric diseases, but rarely in low-grade hepatic encephalopathy (HE), a common neuropsychiatric complication of liver cirrhosis. We conducted a resting-state fMRI in 19 healthy controls, 18 cirrhotic patients without HE, and 22 cirrhotic patients with low-grade HE. The amplitude of low-frequency fluctuations (ALFF) of fMRI signal was computed to measure the spontaneous neuronal activity. Several regions showing significant ALFF differences among three groups were the precuneus, occipital lobe, left frontal lobe and anterior/middle cingulate cortex, and left cerebellum posterior lobe. Compared to controls or patients without HE, patients with low-grade HE showed decreased ALFF in the precuneus and adjacent cuneus, visual cortex, and left cerebellum posterior lobe. Compared to controls, patients with low-grade HE showed higher ALFF in both cortical and subcortical regions, including the right middle cingulate gyrus, and left anterior/middle cingulate gyrus, inferior frontal gyrus, insula lobe, parahippocampal gyrus, middle temporal gyrus and lentiform nucleus; compared to patients without HE, patients with low-grade HE showed higher ALFF in the left medial frontal gyrus and anterior cingulate gyrus, bilateral superior frontal gyrus, and right middle frontal gyrus. Moreover, correlations between ALFF changes and poor neurocognitive performances were found in patients with low-grade HE. These results suggested the existence of aberrant brain activity at the baseline state in low-grade HE, which may be implicated in the neurological pathophysiology underlying HE.

Hepatic encephalopathy after transjugular intrahepatic portosystemic shunt

Transjugular intrahepatic portosystemic shunt (TIPS) has been used for more than 20 years to treat some of the complications of portal hypertension. When TIPS was initially proposed, it was claimed that the optimal calibration of the shunt could allow an adequate reduction of portal hypertension, avoiding, at the same time, the occurrence of hepatic encephalopathy (HE), a neurologic syndrome. However, several clinical observations have shown that HE occurred rather frequently after TIPS, and HE has become an important issue to be taken into consideration in TIPS candidates and a problem to be faced after the procedure.

New perspectives in hepatic encephalopathy

The terminology of hepatic encephalopathy (HE) remained poorly defined for decades. One major problem was the lack of definition of what constituted acute versus chronic HE. Chronic HE caused more confusion because it was proposed to signify any bout of HE in patients with chronic liver disease, whereas others thought it denoted a protracted period of loss of consciousness. Numerous other versions were rampant. This mass confusion was solved by the report of the Hepatic Encephalopathy Consensus Group at the World Congress of Gastroenterology in 1998. This new multi-axial definition led to standardization of diagnosis and explosion in the field of research in HE.

Assessment of minimal hepatic encephalopathy (with emphasis on computerized psychometric tests)

Minimal hepatic encephalopathy (MHE) is associated with a high risk of development of overt hepatic encephalopathy, impaired quality of life, and driving accidents. The detection of MHE requires specialized testing because it cannot, by definition, be diagnosed on standard clinical examination. Psychometric and neurophysiologic techniques are often used to test for MHE. Paper-pencil psychometric batteries and computerized tests have proved useful in diagnosing MHE and predicting its outcomes. Neurophysiologic tests also provide useful information. The diagnosis of MHE is an important issue for clinicians and patients alike. Testing strategies depend on the normative data available, patient comfort, and local expertise.

[Hepatic encephalopathy and colon pathology in liver cirrhosis]

to define a role of structural and functional changes of a colon, expression indicators of epithelial cells of mucous coat of colon that produce serotonin and hromogranin-A at in encephalopathy development at liver cirrhoses. We have examined 146 patients with liver cirrhosis of various classes using the clinical, endoscopic, morphologic and immunohistochemical methods. It is established that with increase of a class of a cirrhosis frequency of revealing of a hepatic encephalopathy, structural changes, degree dysbacteriosis of a colon. Progressing of a hepatic encephalopathy at liver cirrhoses associates with development destructive and atrophic changes of a mucous membrane of a colon and a dysbacteriosis. The increase in the morphometric rates of epithelial cells of mucous coat of colon that produce serotonin and hromogranin-A at liver cirrhoses plays a part in development of a manifesting of a hepatic encephalopathy.

White matter microsusceptibility changes in patients with hepatic encephalopathy

We report a new radiological finding in two patients with hepatic encephalopathy. A new susceptibility-weighted (SWI) magnetic resonance imaging sequence revealed multiple bilateral microsusceptibility changes in the corpus callosum and white matter, while the conventional T1 and T2 weighted images were unremarkable. We postulate that the etiology of the microsusceptibility changes may be related to hepatic coagulopathy and other factors, such as impaired cerebral blood flow and brain edema.

A randomized double blind placebo controlled trial of probiotics in minimal hepatic encephalopathy

BACKGROUND AND AIM

Hepatic encephalopathy (HE) is a common and serious complication of liver disease. Minimal HE has major impact on all aspects of a patient's life. The aim of this study was to asses the efficacy of probiotics in minimal hepatic encephalopathy in patients with cirrhosis of the liver.

METHODS

Stable cirrhotics with minimal hepatic encephalopathy diagnosed by number connection test and evoked responses were recruited for the study. The patients were randomized to two groups and the drugs were administered in a double blind fashion. Improvement in number connection test score, evoked response time and arterial ammonia levels were noted.

RESULTS

43 patients were recruited for the study; 21 in the probiotics group and 22 in the placebo group. There was no statistically significant change in the parameters like arterial ammonia, evoked responses and number connection test before and after treatment with probiotics when compared to placebo.

CONCLUSION

Short term administration of probiotics did not produce any significant improvement in the various parameters assessed in patients with minimal hepatic encephalopathy when compared with placebo.