Predictors of minimal hepatic encephalopathy in patients with cirrhosis

Correlation of ammonia and blood laboratory parameters with hepatic encephalopathy: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Emerging research suggests that hyperammonemia may enhance the probability of hepatic encephalopathy (HE), a condition associated with elevated levels of circulating ammonia in patients with cirrhosis. However, some studies indicate that blood ammonia levels may not consistently correlate with the severity of HE, highlighting the complex pathophysiology of this condition.

METHODS

A systematic review and meta-analysis through PubMed, Scopus, Embase, Web of Science, and Virtual Health Library were conducted to address this complexity, analyzing and comparing published data on various laboratory parameters, including circulating ammonia, blood creatinine, albumin, sodium, and inflammation markers in cirrhotic patients, both with and without HE.

RESULTS

This comprehensive review, which included 81 studies from five reputable databases until June 2024, revealed a significant increase in circulating ammonia levels in cirrhotic patients with HE, particularly those with overt HE. Notably, significant alterations were observed in the circulating creatinine, albumin, sodium, interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNFα) in HE patients.

CONCLUSIONS

These findings suggest an association between ammonia and HE and underscore the importance of considering other blood parameters such as creatinine, albumin, sodium, and pro-inflammatory cytokines when devising new treatment strategies for HE.

Psychometric Hepatic Encephalopathy Score for the Diagnosis of Minimal Hepatic Encephalopathy in Thai Cirrhotic Patients

The psychometric hepatic encephalopathy score (PHES) is the gold standard for diagnosing minimal hepatic encephalopathy (MHE). Screening for MHE is frequently overlooked in clinical practice due to time constraints. Furthermore, the simplified animal naming test (S-ANT1) is a new simple tool for evaluating MHE in cirrhotic patients. The purpose of this study was to standardize the PHES in a healthy Thai population, assess the prevalence of MHE, and validate the S-ANT1 in detecting MHE in patients with cirrhosis. The study included 194 healthy controls and 203 cirrhotic patients without overt HE. Psychometric tests and the S-ANT1 were administered to all participants. Multiple linear regression was used to analyze factors related to PHES results, and formulas were developed to predict the results for each PHES subtest. In healthy controls, age and education were predictors of all five subtests. The PHES of the control group was −0.26 ± 2.28 points, and the threshold for detecting MHE was set at ≤ −5 points. The cirrhotic group had PHES values of −2.6 ± 3.1 points. Moreover, MHE was found to be present in 26.6% of cirrhotic patients. S-ANT1 had a moderate positive correlation with PHES (r = 0.44, p < 0.001). S-ANT1 < 22 named animals detected MHE with a sensitivity of 71.2%, specificity of 65%, and area under the receiver operating curve of 0.68 (p < 0.001). In conclusion, Thai PHES normative data have been developed to detect MHE in cirrhotic patients who do not have overt HE. The optimal cutoff for detecting MHE in Thai cirrhotic patients was PHES ≤ −5 points and S-ANT1 < 22 named.

Efficacy of rifaximin against covert hepatic encephalopathy and hyperammonemia in Japanese patients

Covert hepatic encephalopathy (CHE) impairs patient quality of life and occurs in approximately 30% of liver cirrhosis (LC) cases. Japanese clinical practice guidelines recommend rifaximin to treat overt HE (OHE). However, the usefulness of rifaximin against CHE is not thoroughly investigated in Japanese patients. We aimed to investigate the efficacy of rifaximin against hyperammonemia and CHE in Japan. We observed 102 patients with HE showing hyperammonemia secondary to LC and examined various biochemical and behavioral parameters following rifaximin treatment. CHE was diagnosed when the patients exhibited two or more abnormal neuropsychological test (NPT) scores but did not indicate OHE symptoms. In the 102 cases, a significant therapeutic effect of rifaximin on hyperammonemia was observed from 2 to 48 weeks after starting treatment. Excluding 10 patients diagnosed with OHE upon starting rifaximin treatment, 12 of the 92 remaining patients (11.8%) transitioned to OHE within 1 year. The 1 year cumulative OHE transition rate was 14.5%. Among the 24 patients with CHE diagnosed by the NPT for whom NPT results could be evaluated at 4 and 12 weeks after starting treatment, 10 (41.6%) had recovered from CHE at 12 weeks. When the factors contributing to recovery from CHE were examined by multivariate analysis, an ammonia level <129 μg/dL was a significant factor. Rifaximin was thus significantly effective against both hyperammonemia and CHE in Japanese patients.

Current approach to treatment of minimal hepatic encephalopathy in patients with liver cirrhosis

Minimal hepatic encephalopathy (MHE) corresponds to the earliest stage of hepatic encephalopathy (HE). MHE does not present clinically detectable neurological-psychiatric abnormalities but is characterized by imperceptible neurocognitive alterations detected during routine clinical examination via neuropsychological or psychometrical tests. MHE may affect daily activities and reduce job performance and quality of life. MHE can increase the risk of accidents and may develop into overt encephalopathy, worsening the prognosis of patients with liver cirrhosis. Despite a lack of consensus on the therapeutic indication, interest in finding novel strategies for prevention or reversion has led to numerous clinical trials; their results are the main objective of this review. Many studies address the treatment of MHE, which is mainly based on the strategies and previous management of overt HE. Current alternatives for the management of MHE include measures to maintain nutritional status while avoiding sarcopenia, and manipulation of intestinal microbiota with non-absorbable disaccharides such as lactulose, antibiotics such as rifaximin, and administration of different probiotics. This review analyzes the results of clinical studies that evaluated the effects of different treatments for MHE.

Auditory and visual P300 event-related potentials to detect minimal hepatic encephalopathy

INTRODUCTION

Diagnosis of Minimal hepatic encephalopathy (MHE) requires psychometric tests, although new methods are needed since sensitivity, specificity, and accuracy are low. The P300 event-related potential (ERP) is obtained by auditory and visual stimuli, although only the auditory P300 has been used to detect MHE. We aimed to compare the diagnostic features of auditory and visual P300 to detect MHE.

MATERIALS AND METHODS

Sixty patients with liver cirrhosis and thirty-five healthy controls completed the Psychometric Hepatic Encephalopathy Score (PHES), the critical flicker frequency (CFF), auditory, and visual P300. MHE was diagnosed if PHES and CFF scores were abnormal.

RESULTS

Fifty-three cirrhotic patients (age 54.5±8.6 years) completed all tests. Abnormal scores were: PHES (49.1%), CFF (67.9%). The proportion of MHE was 21.4%. The area under the receiver operating ROC curves (AUROC) for auditory P300 was better than visual P300 for distinguishing MHE from controls (AUROC 0.792 vs 0.725; p<0.005 for both; accuracy 73.8%vs 70.2%; sensitivity 72.2% both; specificity 74.2 vs 69.7, respectively. Among cirrhotic patients, only auditory P300 was useful to detect MHE, AUROC 0.723 p<0.05; 77.4% accuracy; 61.1% sensitivity; and 81.8% specificity.

CONCLUSIONS

The auditory P300 sensitivity, specificity, and accuracy were similar to those of CFF. Our results showed that only auditory P300 is useful to differentiate patients with MHE. Although both modalities, auditory and visual, differentiated patients with cirrhosis from controls, we consider the visual P300 is not suitable for detecting MHE.

Prediction of minimal encephalopathy in patients with HCV-related cirrhosis using albumin-bilirubin, platelets-albumin-bilirubin score, albumin-bilirubin-platelets grade and ammonia level

Background

Minimal hepatic encephalopathy (MHE) is a complication of liver cirrhosis causing low quality of life, driving skills and higher traffic violation. The neuro-psychometric tests are the gold standard but difficult clinically and time-consuming. The aim was to assess albumin-bilirubin (ALBI), platelets-albumin-bilirubin (PALBI) score, albumin-bilirubin-platelets (ALBI-PLT) grade and ammonia level as MHE predictors. All the patients (n = 257) underwent critical flicker frequency number connection, serial dotting and digit symbol test for MHE diagnosis (n = 166, 64.6%). Liver function, INR, CBC and arterial ammonia were measured.

Results

There was statistically significant difference (p < 0.05) between MHE patients and those without as regards ammonia (86.59 ± 23.25 vs. 63.56 ± 24.2 μmol/L), ALBI score (−2.13 ± 0.53 vs. −2.49 ± 0.38), PALBI score (−2.33 ± 0.39 vs. −2.55 ± 0.26) and ALBI-PLT (3.98 ± 0.49 vs. 3.70 ± 0.56). Patients with MHE were mainly Child-Pugh B and C and also ALBI grade 2 and 3. For MHE discrimination, ALBI, PALBI, ALBI-PLT and ammonia had the following cutoffs >−2.36 (57.23% sensitivity, 77.78% specificity), >−2.5 (60.84% sensitivity, 67.9% specificity), > 3 (87.35% sensitivity, 27.16% specificity) and > 76.5 (69% sensitivity, 72.5% specificity) respectively (p = 0.001). On comparison of the area under the curve, ALBI is comparable to PALBI (p = 0.245) and ammonia (p = 0.603). The ALBI-PLT is inferior to ALBI (p = 0.018) and ammonia (p = 0.021) but comparable to PALBI (p = 0.281). ALBI (odds = 5.64), PALBI (odds = 7.86), ALBI-PLT (odds = 2.86), ammonia (odds = 1.05), Child-Pugh score (odds = 2.13), MELD (odds = 1.26) are independent predictors of MHE.

Conclusion

ALBI, PALBI and ammonia are clinical useful model for MHE prediction.

Prevalence of minimal hepatic encephalopathy among patients with chronic liver disease in Ilorin, Nigeria

Background

Minimal Hepatic encephalopathy is the mildest form of Hepatic Encephalopathy which presents with significant cognitive impairment and affectation of activities of daily living. The literature is scanty on the prevalence of minimal hepatic encephalopathy in Nigerians with chronic liver disease.

Aim

This study aimed at determining the prevalence of minimal hepatic encephalopathy among patients with chronic liver disease using neuro-psychometric tests.

Methods

The study was a hospital-based cross-sectional study carried out at the University of Ilorin Teaching Hospital, Ilorin from February 2015 to February 2016. Chronic liver disease was diagnosed with the presence of peripheral stigmata of liver disease, liver biochemistry, prothrombin time, and sonographic findings in keeping with liver disease. Minimal hepatic encephalopathy was diagnosed using number connection tests-A and B for patients who were educated while Line tracing test and constructional dyspraxia were used for patients without any formal education. Data obtained were analysed using Statistical Package for the Social Sciences (SPSS) version 20 computer software package.

Results

Sixty-four patients with chronic liver disease were recruited. The mean age (SD) of the patients was 47.1±14.6 yrs, and the 30-39 and 40-49 yrs age groups each had the highest frequency of 21(32.8%). There were 54 (84.4%) males and 10 (15.6%) females. The prevalence of Minimal Hepatic Encephalopathy was 43.8%.

Conclusion

The prevalence of Minimal Hepatic Encephalopathy in this study was similar to previous studies. Significant number of patients with minimal HE were in Child-Pugh class B and C.

Funding

None.

Diabetes mellitus increases the risk of hepatic encephalopathy after a transjugular intrahepatic portosystemic shunt in cirrhotic patients

OBJECTIVE

The aim of this study was to examine the effect of diabetes mellitus (DM) on the rate of hepatic encephalopathy (HE) in patients with decompensated liver cirrhosis after the creation of a transjugular intrahepatic portosystemic shunt (TIPS).

PATIENTS AND METHODS

This study retrospectively reviewed 436 consecutive patients with cirrhosis receiving TIPS in our department from 2008 to 2016. By comparing two groups of patients, with or without DM, the incidence of developing overt HE after TIPS, as well as the correlation between diabetes and HE, was analyzed. Data were analyzed using the χ-tests, unpaired t-tests, logistic regression, and Kaplan-Meier curves. After the initial data processing, we used a regression model to analyze whether or not DM is associated with the development of HE after TIPS.

RESULTS

Of the 436 patients who underwent TIPS, 85 (19.5%) had diabetes at admission and 126 (28.9%) had HE after TIPS. Patients with DM more frequently had HE compared with those without DM (44.7 vs. 25.1%; P = 0.000). The logistic regression analysis showed that DM (P = 0.015) and age (P = 0.002) were independent risk factors for HE after TIPS. Finally, using the Kaplan-Meier curves, we found that diabetes significantly increases the incidence of overt HE (log-rank P = 0.026).

CONCLUSION

Similar to old age, DM may increase the risk of HE in cirrhotic patients after the creation of TIPS.

Detection of Minimal Hepatic Encephalopathy in Iranian Patients with Cirrhosis

BACKGROUND

Minimal hepatic encephalopathy (MHE) is the mildest type of hepatic encephalopathy in patients with cirrhosis. Patients with MHE have normal clinical and physical examination but they show some neurocognitive dysfunctions that affect their quality of life negatively. The aim of the current study is to diagnose MHE in patients with cirrhosis and its associated factors.

METHODS

This is a cross-sectional study on 120 known cases of cirrhosis referred to hospitals affiliated to Isfahan University of Medical Sciences during 2014-17. The patients’ cirrhosis severity was evaluated using laboratory tests and physical examinations based on MELD (Model for End-stage Liver Disease) and Child-Pugh criteria. The patients’ demographics were filled in a checklist. All included patients with cirrhosis were asked to respond to the questions of Psychometric Hepatic Encephalopathy Score (PHES) test.

RESULTS

Mean age of the patients was 51.2 ± 9.7 years. 62 (51.7%) patients were men and 58 (48.3%) patients were women. The mean score of the patients based on MELD criteria was 14.03 ± 6.09. 26.7% of the patients presented MHE. Mean age of the patients with MHE was statistically less than the patients without MHE (p value < 0.001). Mean score of MELD criteria among the patients with diagnosis of MHE was significantly higher than the other group (p value < 0.001). The patients’ Child class was statistically associated with MHE (p value < 0.001). Men were significantly more affected than women (p value = 0.03).

CONCLUSION

MHE was associated with MELD score and Child class of the patients with cirrhosis. The noticeable point was reversible association of age with MHE. Further studies are recommended.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Prevalence of and Factors Associated With Minimal Hepatic Encephalopathy in Patients With Cirrhosis of Liver

BACKGROUND/OBJECTIVES

Minimal hepatic encephalopathy (MHE), though highly prevalent, is a frequently underdiagnosed complication of cirrhosis of the liver. Because lack of time is reported as the major reason for non-testing, identifying patients at high risk of MHE would help in targeting them for screening. We aimed to determine the factors associated with MHE to help identify patient subgroups with a higher risk of MHE for targeted screening.

METHODS

Patients with cirrhosis of liver presenting between April 2015 and November 2016 were included. Those with a Psychometric Hepatic Encephalopathy Score (PHES) of ≤-5 points on psychometric testing were diagnosed to have MHE. Various demographic, clinical and laboratory parameters were included in a univariate and later multiple logistic regression models.

RESULTS

Of the 180 (male = 166, 92.2%) patients included 94 (52.2%) had MHE. Though serum albumin, serum total bilirubin, serum aspartate aminotransferase, international normalized ration, Child-Turcotte-Pugh and Model-For-End-Stage-Liver-Disease scores were significant on univariate analysis, only CTP score was found to be significantly associated with MHE (P = 0.002) on multivariate analysis. A higher CTP class was associated with a higher risk of the presence of MHE. The Odds ratio for having MHE was higher with CTP classes of B (P ≤ 0.001) and C (P ≤ 0.001) compared to class A.

CONCLUSIONS

MHE is a common complication in patients with cirrhosis of liver and higher CTP scores independently predict the presence of MHE. Patients with CTP class B and C have a higher risk of suffering from MHE than CTP class A. Screening of patients in CTP class B and C is likely to increase the MHE detection rates while saving time, although select CTP class A patients may also need screening in view of public safety or poor quality of life.

Sarcopenia predicts minimal hepatic encephalopathy in patients with liver cirrhosis

AIM

Minimal hepatic encephalopathy (MHE) and sarcopenia impair the health-related quality of life and prognosis of patients with liver cirrhosis; however, the relationship between MHE and sarcopenia remains unclear. The aim of this study was to investigate their relationship and to identify the predictors of MHE in cirrhotic patients.

METHODS

This retrospective study evaluated 120 cirrhotic patients who were tested for MHE and sarcopenia. Minimal hepatic encephalopathy was diagnosed by using the computer-aided neuropsychiatric test. Sarcopenia was diagnosed based on the assessment criteria recommended by the Japan Society of Hepatology. Muscle mass and muscle strength were measured by using bio-impedance analysis and digital grip strength dynamometer. Univariate and multivariate logistic regression analyses were carried out to identify the predictors of MHE.

RESULTS

Of the 120 cirrhotic patients, 28 (23%) and 32 (27%) were diagnosed with MHE and sarcopenia, respectively. The prevalence of MHE was higher in patients with sarcopenia than in those without sarcopenia (P = 0.01). By the univariate analysis, MHE was significantly complicated with sarcopenia (P < 0.01). In the multivariate analysis, sarcopenia (odds ratio = 3.31, 95% confidence interval = 1.19-9.42; P = 0.02) and serum branched-chain amino acids levels <327 nmol/mL (odds ratio = 2.98, 95% confidence interval = 1.08-8.34; P = 0.03) were found to be associated with MHE.

CONCLUSIONS

Sarcopenia and serum branched-chain amino acids levels were predictors of MHE. The amelioration of sarcopenia and/or amino acids imbalance may improve MHE in patients with liver cirrhosis.

Minimal hepatic encephalopathy: A review

Minimal hepatic encephalopathy (MHE) is the earliest form of hepatic encephalopathy and can affect up to 80% of patients with liver cirrhosis. By definition, MHE is characterized by cognitive function impairment in the domains of attention, vigilance and integrative function, but obvious clinical manifestation are lacking. MHE has been shown to affect daily functioning, quality of life, driving and overall mortality. The diagnosis can be achieved through neuropsychological testing, recently developed computerized psychometric tests, such as the critical flicker frequency and the inhibitory control tests, as well as neurophysiological procedures. Event related potentials can reveal subtle changes in patients with normal neuropsychological performances. Spectral analysis of electroencephalography (EEG) and quantitative analysis of sleep EEG provide early markers of cerebral dysfunction in cirrhotic patients with MHE. Neuroimaging, in particular MRI, also increasingly reveals diffuse abnormalities in intrinsic brain activity and altered organization of functional connectivity networks. Medical treatment for MHE to date has been focused on reducing serum ammonia levels and includes non-absorbable disaccharides, probiotics or rifaximin. Liver transplantation may not reverse the cognitive deficits associated with MHE. We performed here an updated review on epidemiology, burden and quality of life, neuropsychological testing, neuroimaging, neurophysiology and therapy in subjects with MHE.

Child-Pugh Versus MELD Score for the Assessment of Prognosis in Liver Cirrhosis: A Systematic Review and Meta-Analysis of Observational Studies

Child-Pugh and MELD scores have been widely used for the assessment of prognosis in liver cirrhosis. A systematic review and meta-analysis aimed to compare the discriminative ability of Child-Pugh versus MELD score to assess the prognosis of cirrhotic patients.PubMed and EMBASE databases were searched. The statistical results were summarized from every individual study. The summary areas under receiver operating characteristic curves, sensitivities, specificities, positive and negative likelihood ratios, and diagnostic odds ratios were also calculated.Of the 1095 papers initially identified, 119 were eligible for the systematic review. Study population was heterogeneous among studies. They included 269 comparisons, of which 44 favored MELD score, 16 favored Child-Pugh score, 99 did not find any significant difference between them, and 110 did not report the statistical significance. Forty-two papers were further included in the meta-analysis. In patients with acute-on-chronic liver failure, Child-Pugh score had a higher sensitivity and a lower specificity than MELD score. In patients admitted to ICU, MELD score had a smaller negative likelihood ratio and a higher sensitivity than Child-Pugh score. In patients undergoing surgery, Child-Pugh score had a higher specificity than MELD score. In other subgroup analyses, Child-Pugh and MELD scores had statistically similar discriminative abilities or could not be compared due to the presence of significant diagnostic threshold effects.Although Child-Pugh and MELD scores had similar prognostic values in most of cases, their benefits might be heterogeneous in some specific conditions. The indications for Child-Pugh and MELD scores should be further identified.

Minimal hepatic encephalopathy

Minimal hepatic encephalopathy (MHE) is the earliest form of hepatic encephalopathy and can affect up to 80% of cirrhotic patients. By definition, it has no obvious clinical manifestation and is characterized by neurocognitive impairment in attention, vigilance and integrative function. Although often not considered to be clinically relevant and, therefore, not diagnosed or treated, MHE has been shown to affect daily functioning, quality of life, driving and overall mortality. The diagnosis of MHE has traditionally been achieved through neuropsychological examination, psychometric tests or the newer critical flicker frequency test. A new smartphone application (EncephalApp Stroop Test) may serve to function as a screening tool for patients requiring further testing. In addition to physician reporting and driving restrictions, medical treatment for MHE includes non-absorbable disaccharides (eg, lactulose), probiotics or rifaximin. Liver transplantation may not result in reversal of the cognitive deficits associated with MHE.

[Minimal hepatic encephalopathy: a better diagnostic to improve prognostic]

BACKGROUND AND AIMS

Minimal hepatic encephalopathy (MHE) is the mildest form of the spectrum of hepatic encephalopathy that impairs health-related quality of life. The aim of this study is to evaluate the prevalence of MHE in patients with liver cirrhosis and analyze risk factors.

METHODS

Between September 2011 and December 2012, consecutive cirrhotic patients seen in our department were evaluated. Patients included were screened by the psychometric hepatic encephalopathy score (PHES) battery comprising 5 tests: number connection test A and B, line tracing test, serial dotting test and digit symbol test. Patients included were regularly followed-up for the development of overt hepatic encephalopathy, driving accidents, falls and death.

RESULTS

We included 45 cirrhotic patients. Etiology of cirrhosis was viral in half of cases. Child-Pugh score was A in 55.6 %, B in 26.7 % and C in 17.8 %. Median Meld score was 14. According to the PHES score, MHE was detected in 44.4 % of patients. Univariate analysis identified 4 variables significantly associated with the presence of MHE: age ≥ 55 years (P=0.031), poor educational status with years of study< 9 years (P=0.007), MELD score ≥ 15 (P=0.002) and Child-Pugh ≥ 7 (P=0.001). At multivariate analysis, the only independent risk factor of MHE was a MELD score≥15 (OR=15.4; P<0.001). During the follow-up, patients with MHE developed more often overt encephalopathy, falls and driving accidents, and had a lower survival, although the difference was not statically significant.

CONCLUSION

In this preliminary small series, prevalence of MHE in Tunisian cirrhotic patient was 44.4 %. A MELD score ≥ 15 was the only independent risk factor. MHE had a negative impact on the outcome, justifying an early diagnostic. Adequate therapy may improve cognitive function.

The mind and liver test: a new approach to the diagnosis of minimal hepatic encephalopathy in resource-poor settings

Background and Aims. Minimal hepatic encephalopathy (MHE) is diagnosed using neuropsychometric tests or neurophysiological tests that are either inapplicable to illiterate patient population in resource-poor settings or require sophisticated and expensive equipment. The available tests assess discrete domains of mental impairment. Our aim was (a) to design a neuropsychometric test that measures all domains of mental impairment in MHE using one metric; (b) to evaluate its sensitivity, specificity, and reproducibility. Methods. The mind and liver test (MALT), a psychometric test assessing cognition, memory, and psychometric impairment, each on a scale of 20, was designed keeping in mind the requirements of a universal test. 40 cirrhotics and 36 controls were subjected to critical flicker frequency (CFF) and MALT in same sitting. ROC curve was plotted for MALT using CFF as gold standard. Bland-Altman plot was used to find test-retest agreement. Results. CFF values and MALT scores varied significantly between the cases and the controls (P < 0.05). MALT was 94% sensitive and 83% specific. Using ROC with CFF as gold standard, the AUC for diagnosis of MHE using MALT score was 0.89. Test-retest agreement was high (ICC = 0.89). Conclusion. In this pilot study, MALT proved to be highly sensitive, specific, inexpensive, and reproducible.

Meta-analysis: The diagnostic accuracy of critical flicker frequency in minimal hepatic encephalopathy

BACKGROUND

Minimal hepatic encephalopathy (MHE) reduces quality of life, increases the risk of road traffic incidents and predicts progression to overt hepatic encephalopathy and death. Current psychometry-based diagnostic methods are effective, but time-consuming and a universal 'gold standard' test has yet to be agreed upon. Critical Flicker Frequency (CFF) is a proposed language-independent diagnostic tool for MHE, but its accuracy has yet to be confirmed.

AIM

To assess the diagnostic accuracy of CFF for MHE by performing a systematic review and meta-analysis of all studies, which report on the diagnostic accuracy of this test.

METHODS

A systematic literature search was performed to locate all publications reporting on the diagnostic accuracy of CFF for MHE. Data were extracted from 2 × 2 tables or calculated from reported accuracy data. Collated data were meta-analysed for sensitivity, specificity, diagnostic odds ratio (DOR) and summary receiver operator curve (sROC) analysis. Prespecified subgroup analysis and meta-regression were also performed.

RESULTS

Nine studies with data for 622 patients were included. Summary sensitivity was 61% (95% CI: 55-67), specificity 79% (95% CI: 75-83) and DOR 10.9 (95% CI: 4.2-28.3). A symmetrical sROC gave an area under the receiver operator curve of 0.84 (SE = 0.06). The heterogeneity of the DOR was 74%.

CONCLUSIONS

Critical Flicker Frequency has a high specificity and moderate sensitivity for diagnosing minimal hepatic encephalopathy. Given the advantages of language independence and being both simple to perform and interpret, we suggest the use of critical flicker frequency as an adjunct (but not replacement) to psychometric testing.

Metformin inhibits glutaminase activity and protects against hepatic encephalopathy

AIM

To investigate the influence of metformin use on liver dysfunction and hepatic encephalopathy in a retrospective cohort of diabetic cirrhotic patients. To analyze the impact of metformin on glutaminase activity and ammonia production in vitro.

METHODS

Eighty-two cirrhotic patients with type 2 diabetes were included. Forty-one patients were classified as insulin sensitizers experienced (metformin) and 41 as controls (cirrhotic patients with type 2 diabetes mellitus without metformin treatment). Baseline analysis included: insulin, glucose, glucagon, leptin, adiponectin, TNFr2, AST, ALT. HOMA-IR was calculated. Baseline HE risk was calculated according to minimal hepatic encephalopathy, oral glutamine challenge and mutations in glutaminase gene. We performed an experimental study in vitro including an enzymatic activity assay where glutaminase inhibition was measured according to different metformin concentrations. In Caco2 cells, glutaminase activity inhibition was evaluated by ammonia production at 24, 48 and 72 hours after metformina treatment.

RESULTS

Hepatic encephalopathy was diagnosed during follow-up in 23.2% (19/82): 4.9% (2/41) in patients receiving metformin and 41.5% (17/41) in patients without metformin treatment (logRank 9.81; p=0.002). In multivariate analysis, metformin use [H.R.11.4 (95% CI: 1.2-108.8); p=0.034], age at diagnosis [H.R.1.12 (95% CI: 1.04-1.2); p=0.002], female sex [H.R.10.4 (95% CI: 1.5-71.6); p=0.017] and HE risk [H.R.21.3 (95% CI: 2.8-163.4); p=0.003] were found independently associated with hepatic encephalopathy. In the enzymatic assay, glutaminase activity inhibition reached 68% with metformin 100 mM. In Caco2 cells, metformin (20 mM) decreased glutaminase activity up to 24% at 72 hours post-treatment (p<0.05).

CONCLUSIONS

Metformin was found independently related to overt hepatic encephalopathy in patients with type 2 diabetes mellitus and high risk of hepatic encephalopathy. Metformin inhibits glutaminase activity in vitro. Therefore, metformin use seems to be protective against hepatic encephalopathy in diabetic cirrhotic patients.

Critical flicker frequency and continuous reaction times for the diagnosis of minimal hepatic encephalopathy: a comparative study of 154 patients with liver disease

Minimal hepatic encephalopathy (MHE) is intermittently present in up to 2/3 of patients with chronic liver disease. It impairs their daily living and can be treated. However, there is no consensus on diagnostic criteria except that psychometric methods are required. We compared two easy-to-perform reproducible bedside methods: the critical flicker frequency (CFF) and continuous reaction times (CRT) tests. A CFF <39 Hz and CRT-index <1.9 (index: the ratio 50/(90 minus 10) percentiles of reaction times) indicates cerebral dysfunction. 154 patients with acute or chronic liver disease with out overt hepatic encephalopathy (HE) underwent both tests at the same occasion. Both tests were abnormal in 20% of the patients and both tests were normal in 40% of the patients. In more than 1/3 the two tests were not in agreement as CFF classified 32% and CRT-index classified 48% of the patients as having MHE (p < 0.005). The two tests were weakly linearly correlated (r(2) = 0.14, p < 0.001) and neither test correlated with the metabolic liver function measured by the Galactose Elimination Capacity (GEC), nor with the blood ammonia concentration. Both tests identified a large fraction of the patients as having MHE and cleared only 40%. The two tests did not show concordant results, likely because they describe different aspects of MHE: the CFF gives a measure of astrocytic metabolic state and hence pathogenic aspects of MHE, whereas the CRT measures a composite key performance, viz. the ability of reacting appropriately to a sensory stimulus. The choice of test depends on the information needed in the clinical and scientific care and study of the patients.

Advances in the evaluation and management of minimal hepatic encephalopathy

Minimal hepatic encephalopathy (MHE) is a neurocognitive disorder that affects up to 80% of cirrhotic patients. Similar to overt hepatic encephalopathy, ammonia and oxidative stress play key roles in the pathogenesis of MHE. However, MHE is characterized by subtle deficits and psychomotor abnormalities that can only be elicited by specialized psychometric tests. Although no gold standard exists for the diagnosis, MHE remains an important entity for clinicians to recognize because of its negative impact on a patient's health-related quality of life and association with driving impairment and vehicle accidents. MHE has also been associated with an increased rate in the development of overt hepatic encephalopathy and increased mortality; therefore, identification and treatment should not be delayed. Treatment to date has been focused on reducing serum ammonia levels with agents such as lactulose, probiotics, and synbiotics. MHE is a real and growing problem that is epidemic in cirrhosis, and increasing awareness of this condition is necessary for adequate management of these patients.