[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.