Comparison of the most favoured methods for the diagnosis of hepatic encephalopathy in liver transplantation candidates

Comparison of 6 tests for diagnosing minimal hepatic encephalopathy and predicting clinical outcome: A prospective, observational study

BACKGROUND AND AIMS

Current guidelines recommend the assessment for minimal HE in patients with liver cirrhosis. Various efforts were made to find tools that simplify the diagnosis. Here, we compare the 6 most frequently used tests for their validity and their predictive value for overt hepatic encephalopathy (oHE), rehospitalization, and death.

APPROACH AND RESULTS

One hundred thirty-two patients with cirrhosis underwent the Portosystemic Encephalopathy-Syndrome-Test yielding the psychometric hepatic encephalopathy score (PHES), Animal Naming Test (ANT), Critical Flicker Frequency (CFF), Inhibitory Control Test (ICT), EncephalApp (Stroop), and Continuous Reaction Time Test (CRT). Patients were monitored for 365 days regarding oHE development, rehospitalization, and death. Twenty-three patients showed clinical signs of HE grade 1-2 at baseline. Of the remaining 109 neurologically unimpaired patients, 35.8% had abnormal PHES and 44% abnormal CRT. Percentage of abnormal Stroop (79.8% vs. 52.3%), ANT (19.3% vs. 51.4%), ICT (28.4% vs. 36.7%), and CFF results (18.3% vs. 25.7%) changed significantly when adjusted norms were used for evaluation instead of fixed cutoffs. All test results correlated significantly with each other ( p <0.05), except for CFF. During follow-up, 24 patients developed oHE, 58 were readmitted to the hospital, and 20 died. Abnormal PHES results were linked to oHE development in the multivariable model. No other adjusted test demonstrated predictive value for any of the investigated endpoints.

CONCLUSIONS

Where applicable, the diagnosis of minimal HE should be made based on adjusted norm values for the tests, exclusively. The minimal HE tests cannot be equated with one another and have an overall limited value in predicting clinical outcomes.

Development and validation of the AMMON-OHE model to predict risk of overt hepatic encephalopathy occurrence in outpatients with cirrhosis

BACKGROUND & AIMS

Neuropsychological and psychophysical tests are recommended to assess the risk of overt hepatic encephalopathy (OHE), but their accuracy is limited. Hyperammonaemia is central in the pathogenesis of OHE, but its predictive utility is unknown. In this study, we aimed to determine the role of neuropsychological or psychophysical tests and ammonia, and to develop a model (AMMON-OHE) to stratify the risk of subsequent OHE development in outpatients with cirrhosis.

METHODS

This observational, prospective study included 426 outpatients without previous OHE from three liver units followed for a median of 2.5 years. Psychometric hepatic encephalopathy score (PHES) <-4 or critical flicker frequency (CFF) <39 was considered abnormal. Ammonia was normalized to upper limit of normal (AMM-ULN) at the respective reference laboratory. Multivariable frailty competing risk and random survival forest analyses were performed to predict future OHE and to develop the AMMON-OHE model. External validation was carried out using 267 and 381 patients from two independent units.

RESULTS

Significant differences were found in time-to-OHE (log-rank p <0.001) according to PHES or CFF and ammonia, with the highest risk in patients with abnormal PHES plus high AMM-ULN (hazard ratio 4.4; 95% CI 2.4-8.1; p <0.001 compared with normal PHES and AMM-ULN). On multivariable analysis, AMM-ULN but not PHES or CFF was an independent predictor of the development of OHE (hazard ratio 1.4; 95% CI 1.1-1.9; p = 0.015). The AMMON-OHE model (sex, diabetes, albumin, creatinine and AMM-ULN) showed a C-index of 0.844 and 0.728 for the prediction of a first episode of OHE in two external validation cohorts.

CONCLUSIONS

In this study, we developed and validated the AMMON-OHE model, comprising readily available clinical and biochemical variables that can be used to identify outpatients at the highest risk of developing a first episode of OHE.

IMPACT AND IMPLICATIONS

In this study, we aimed to develop a model to predict which patients with cirrhosis are at risk of developing overt hepatic encephalopathy (OHE). Using data from three units and including 426 outpatients with cirrhosis, we developed the AMMON-OHE model - comprising sex, diabetes, albumin, creatinine and ammonia levels - which demonstrated good predictive ability. The AMMON-OHE model performs better than PHES and CFF to predict the first episode of OHE in outpatients with cirrhosis. This model was validated in 267 and 381 patients from two independent liver units. The AMMON-OHE model is available online for clinical use.

Predicting overt hepatic encephalopathy after TIPS: Value of three minimal hepatic encephalopathy tests

Background & Aims

Hepatic encephalopathy (HE) is a frequent and severe complication in patients after transjugular intrahepatic portosystemic shunt (TIPS) insertion. However, risk factors for post-TIPS HE remain poorly defined. Minimal HE (mHE) is a well-known risk factor for overt HE in patients with cirrhosis without TIPS. We aimed to evaluate three tools frequently used for diagnosing mHE for their dynamic changes and their predictive value for overt HE after TIPS.

Methods

We prospectively recruited 84 consecutive patients before TIPS insertion and monitored them for 180 days for post-TIPS HE. Before TIPS insertion, the patients underwent the portosystemic encephalopathy (PSE) syndrome test, the animal naming test (ANT), and the critical flicker frequency (CFF). Patients were retested after TIPS insertion.

Results

The majority of patients were male (67.9%), and the predominant indication for TIPS was refractory ascites (75%). Median age was 59 years, model for end-stage liver disease score was 12, and 66.3%, 64.6%, and 28.4% patients had evidence for mHE according to the PSE syndrome test, ANT, and CFF, respectively. Overall, 25 patients developed post-TIPS HE within 180 days after TIPS insertion. Post-TIPS incidence of overt HE was 22.2, 28.6, 45.5, and 55.6% in those with no, one, two, and three pathological tests at baseline, respectively. However, none of the three tests was significantly associated with post-TIPS HE. Of note, mean performance in all tests remained stable over time after TIPS insertion.

Conclusions

PSE syndrome test, ANT and CFF, which are frequently used for diagnosing mHE have limited value for predicting HE after TIPS insertion. We could not find evidence that TIPS insertion leads to a psychometric decline in the long term.

Impact and implications

This prospective observational study compared three diagnostic tests for mHE and showed the limited value of these tests for predicting overt HE in patients with cirrhosis undergoing TIPS insertion. In addition, the results suggest that cognitive performance generally remains stable after TIPS insertion. These results are important for physicians and researchers involved in the management of patients with cirrhosis undergoing TIPS procedures. The study's findings serve as a starting point for further investigations on the development of more effective strategies for predicting and managing post-TIPS HE.

Clinical trial number

ClinicalTrials.gov NCT04801290.

Diagnosis and management of hepatic encephalopathy: The French recommendations

Hepatic encephalopathy (HE) is a frequent and severe complication of liver disease with poor patient outcomes. However, it is a poorly understood complication, with no consensus for diagnosis. Therefore, HE is often underdiagnosed. Differential diagnosis may be cumbersome because of non-specific symptoms, such as confusion, cognitive disorders, the aetiological factors of cirrhosis and comorbidities, which are often observed in cirrhotic patients. Therefore, an overt or covert form of HE should be systematically investigated. Advice is provided to drive patient work-up. Effective treatments are available to prevent or treat HE bouts, but the issue of single or combination therapy has not been resolved. Transjugular intrahepatic portosystemic shunt (TIPS) placement largely improved the prognosis of cirrhotic patients, but HE occurrence of HE is often a fear, even when post-TIPS HE can be avoided by a careful selection of patients and preventive treatment. HE is an indication of liver transplantation. However, its reversibility post-transplantation and the consequences of transplantation in patients with other causes of neurological disorders remain controversial, which supports the performance of an extensive work-up in expert centres for this subset of patients. The present guidelines assist clinicians in the diagnosis of the overt or covert form of HE to implement curative and preventive treatments and clarify which patients require referral to expert centres for consideration for liver transplantation. These guidelines are very clinically oriented and address different frequent clinical issues to help physicians make bedside decisions.

Diabetes mellitus - risk factor and potential future target for hepatic encephalopathy in patients with liver cirrhosis?

Hepatic encephalopathy (HE) is one of the major complications of cirrhosis, and its presence is associated with poor survival. Several risk factors for HE are well established, including age, history of HE, portosystemic shunts, or poorer liver function. In recent years, diabetes mellitus (DM) has emerged as another potential risk factor for the development of HE. This may be important for many patients, as the incidence of type 2 DM (T2DM) is increasing worldwide and, consequently, the incidence of NAFLD-related cirrhosis is rising simultaneously. In addition, DM is a critical factor in the progression of other liver diseases, such as alcohol-related liver disease. Thus, the number of patients with cirrhosis and comorbid T2DM will also increase. To date, the prevalence of DM already ranges between 22 - 40% in patients with cirrhosis. DM-associated factors that may influence the risk of HE include systemic inflammation, insulin resistance with increased muscle protein breakdown as well as autonomic dysfunction with prolonged intestinal transit time and small intestinal bacterial overgrowth. Currently, the evidence for an association between DM and both minimal and overt HE is weak and it seems likely that only poor glycemic control has an impact on HE risk. In addition, there are some early signs indicating that DM may impair the response of patients with HE to pharmacological therapies such as rifaximin. Thus, improvements in the management of glycemic control may be a candidate future target to reduce the risk of HE. In this concise review, we summarize the current evidence on the association between DM and HE and its potential future implications.

Validation of EncephalApp_Stroop as screening tool for the detection of minimal hepatic encephalopathy in German patients with liver cirrhosis

BACKGROUND

In contrast to overt hepatic encephalopathy (OHE), the diagnosis of minimal HE (MHE) is challenging in patients with cirrhosis requiring elaborate, specialized testing. The EncephalApp_Stroop is a smartphone-based application established as screening tool for the diagnosis of MHE but has not yet been validated in a German cohort and country specific cut-offs are currently missing.

METHODS

93 patients with cirrhosis were enroled into this study. Psychometric hepatic encephalopathy score (PHES) was used to detect MHE, and a subset of the patients was tested with critical flicker frequency (CFF). All patients underwent testing with EncephalApp_Stroop. Cut-off thresholds for EncephalApp_Stroop were calculated according to Youden's Index and a separate cut-off was determined with focus on sensitivity.

RESULTS

24 (26%) patients had MHE according to PHES. EncephalApp_Stroop had a strong correlation with PHES (r=-0.76, p<0.001), while there was only a modest correlation with CFF (r=-0.51, <0.001). On time as well as on+off time discriminated best between patients with and without MHE with AUROCS of 0.87 for both measures. According to Youden's index, a cut-off of >224.7 s (sec) (on+off time) discriminated best between patients with and without MHE with a sensitivity of 71% and a specificity of 88%. The adjusted cut-off value for on+off time with focus on sensitivity (sensitivity:specificity weighed 2:1) was 185.1 s, yielding an optimized sensitivity of 92% and a negative predictive value of 96%. By using this cut-off as a pre-screening test in a stepwise diagnosis algorithm, elaborate testing with PHES could have been avoided in 49% of all patients.

CONCLUSION

EncephalApp_Stroop may be useful in a stepwise diagnosis algorithm or even as a stand-alone screening tool to detect MHE in German patients with cirrhosis.

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

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

Liver-Unrelated Comorbid Conditions Do Not Affect Cognitive Performance or Hepatic Encephalopathy Progression in Cirrhosis

INTRODUCTION

We aimed to determine the effect of comorbidities on covert hepatic encephalopathy (CHE) diagnosis and overt hepatic encephalopathy (OHE) development.

METHODS

Cirrhotic outpatients underwent CHE testing and 2-year follow-up. Cox regression was performed for time to OHE. In total, 700 patients (60 years, 84% men, model for end-stage liver disease 11) and 33% prior OHE underwent testing and follow-up.

RESULTS

Major comorbidities were hypertension (54%), diabetes (35%), and depression (29%). Common medications were proton pump inhibitor (49%), beta-blockers (32%), and opioids (21%). Approximately 90 (40%) prior-OHE patients developed recurrence 93 (30,206) days post-testing predicted only by liverrelated variables.

DISCUSSION

Demographics, cirrhosis characteristics, and opioid use, but not other comorbid conditions, were associated with CHE diagnosis and OHE progression.

Determination of Turkish norms of psychometric tests for diagnosing minimal hepatic encephalopathy and proposal of a high sensitive screening test battery

BACKGROUND

Psychometric hepatic encephalopathy score (PHES) needs local standardization.

AIMS

This study aimed at standardizing PHES for Turkish patients and compare them with German norms; to determine minimal hepatic encephalopathy (mHE) prevalence with two different methods [PHES battery and Critical Flicker Frequency (CFF)] and to assess whether sub-tests of the battery can be used for screening for mHE.

METHODS

Healthy volunteers (n = 816; 400 male) and cirrhotics (n = 124; 58 male) were included. For mHE diagnosis PHES score threshold was set at ≤ - 5 points and that of CFF at < 39 Hz. For comparing German and Turkish norms, datasets were combined. Multiple backward procedure was applied to assess effects of age, sex and education on single tests of the battery. Receiver operating characteristic (ROC) curves were created for assessing diagnostic capabilities of subtests of the battery.

RESULTS

PHES norms for Turks were developed. MHE prevalence in compensated cirrhotics was 29.8% and 27.4% with PHES and CFF tests, respectively, with low compatibility (kappa coefficient 0.389); mHE prevalence decreased to 16% when both tests were combined. Turks performed worse vs Germans in the digit symbol (DS) and serial dotting (SD) subtests but performed better in other subtests. In ROC analyzes of subtests, the combination of DS + SD tests achieved an AUROC of 0.974 versus PHES.

CONCLUSIONS

Use of two methods for diagnosing mHE is important for research purposes. From a clinical perspective, sensitivity with acceptable specificity may suffice for screening instruments for mHE. Combined use of DS and SD subtests of the PHES battery appears suitable for this purpose.

Risk of recurrent hepatic encephalopathy in patients with liver cirrhosis: a German registry study

BACKGROUND AND AIMS

Patients with hepatic encephalopathy (HE) show low quality of life, recurrent hospitalizations and an increased mortality. We aimed to assess the natural course of patients after a recent episode of overt HE and to identify risk factors for HE recurrence in Germany.

METHODS

Fifteen sites took part in a prospective, observational study including patients with liver cirrhosis who had been hospitalized for HE within 3 months before recruitment. Clinical data, psychometric hepatic encephalopathy score (PHES) and critical flicker frequency were assessed quarterly for 1 year. Primary endpoint was HE recurrence requiring hospitalization, all-cause-mortality was treated as a competing risk factor.

RESULTS

From January 2014 to March 2016, a total of 115 patients were recruited. Overall 14 premature deaths were documented. For 78 subjects follow-up data were available in accordance with the protocol. After a median of 118 days, more than half of the per-protocol cohort was readmitted to hospital due to HE (N = 34) or died (N = 11). The risk for hospitalization was significantly increased in patients who had been recruited by liver transplant centers (P = 0.003), had had frequent HE relapses prior to recruitment (P = <0.0001) or an abnormal PHES result of <-4 (P = 0.044). Abnormal PHES results barely missed level of significance as an independent risk factor for re-hospitalization in a multivariable competing risk model (P = 0.093).

CONCLUSION

Patients with a history of HE are at high risk for the development of recurrent overt HE demanding hospitalization. The PHES test may aid in detection, monitoring and risk stratification of recurrent HE.

Clinical efficiency of inhibitory control test for the diagnosis of minimal hepatic encephalopathy: A systematic review with meta-analysis

AIM

Minimal hepatic encephalopathy (MHE) is a common neuropsychiatric complication of liver cirrhosis and portosystemic shunt. The inhibitory control test (ICT) is a novel computerized psychometric test for MHE diagnosis, but its efficiency has yet to be confirmed. This study aimed to systematically review the existing evidence concerning the ICT application and then evaluate the efficiency of ICT for MHE diagnosis in clinical practice.

METHODS

A comprehensive search of published works was carried out to identify reports concerning the ICT for MHE diagnosis between January 2000 and December 2020. The pooled sensitivity, specificity, and diagnostic odds ratio of ICT for MHE diagnosis were calculated using a random or fixed effect model. The summary receiver operator characteristic (sROC) curve was constructed, and the area under the sROC curve was calculated. Metaregression and subgroup analyses were used to identify the source of heterogeneity. Publication bias was evaluated using the Deeks funnel plot asymmetry test.

RESULTS

Twelve studies were included in this systematic review, and nine studies enrolling 1022 patients were included in the final meta-analysis. The ICT had a pooled sensitivity, specificity, and DOR of 83%, 64%, and 9, respectively. The area under the sROC curve was 0.79. The metaregression analysis indicated that different locations of studies (relative diagnostic odds ratio, 12.65; p = 0.02) were identified as the source of heterogeneity. No significant publication bias was observed.

CONCLUSIONS

The ICT has a high sensitivity and moderate specificity for MHE diagnosis, and it can be used as a primary diagnostic method for MHE.

Endovascular Management of Hepatic Encephalopathy

Transjugular intrahepatic portosystemic shunt (TIPS) and spontaneous portosystemic shunts (SPSS) may lead to new or worsening hepatic encephalopathy (HE), especially in patients with chronic liver disease. Patients with medically refractory HE (rHE) may benefit from endovascular interventions. In this review, we briefly describe the post-TIPS and SPSS vascular anatomy, pathophysiology, classification, factors associated with HE, and the medical management of HE. In addition, we will discuss current endovascular techniques for HE management, their advantages, disadvantages, and review of the current literature.

Minimal Hepatic Encephalopathy and Biejia-Ruangan Are Associated with First Hospital Readmission in Nonalcoholic Cirrhosis Patients

Introductionand Aim. Patients with cirrhosis are often hospitalized repeatedly for a variety of complications. This retrospective study aimed to assess the effects of minimal hepatic encephalopathy (MHE) and Biejia-Ruangan (BR) on first hospital readmission in nonalcoholic cirrhosis patients without previous overt hepatic encephalopathy (OHE) or hepatocellular carcinoma (HCC). Materials and Methods. A total of 176 hospitalized patients with nonalcoholic cirrhosis were included in this retrospective study. Patients who were first admitted to Beijing Ditan Hospital of Capital Medical University from January 2017 to September 2019 were enrolled. The primary endpoint was their first liver-related hospital readmission. The risk factors for readmission were analyzed by Cox proportional hazard regression analysis. Results. A total of 176 nonalcoholic cirrhosis patients without previous OHE or HCC were included; 57 patients (32.4%) were diagnosed with MHE, and 63 patients (35.8%) were administered BR (2 g, three times a day). Multivariate analysis revealed that nonalcoholic cirrhosis patients with MHE (HR, 5.805; 95% CI, 3.007-11.206; x, P < 0.001) and a higher Model for End-Stage Liver Disease (MELD) score (HR, 1.145; 95% CI, 1.068-1.227; P < 0.001) had an increased risk of first hospital readmission, and patients treated with BR (HR, 0.318; 95% CI, 0.151-0.670; P=0.003) had a decreased risk of first hospital readmission. Conclusion. MHE increased the risk of hospital readmission in nonalcoholic cirrhosis patients without previous OHE or HCC, and this risk was decreased by BR administration.

Pathomechanisms in hepatic encephalopathy

Hepatic encephalopathy (HE) is a frequent neuropsychiatric complication in patients with acute or chronic liver failure. Symptoms of HE in particular include disturbances of sensory and motor functions and cognition. HE is triggered by heterogeneous factors such as ammonia being a main toxin, benzodiazepines, proinflammatory cytokines and hyponatremia. HE in patients with liver cirrhosis is triggered by a low-grade cerebral edema and cerebral oxidative/nitrosative stress which bring about a number of functionally relevant alterations including posttranslational protein modifications, oxidation of RNA, gene expression changes and senescence. These alterations are suggested to impair astrocyte/neuronal functions and communication. On the system level, a global slowing of oscillatory brain activity and networks can be observed paralleling behavioral perceptual and motor impairments. Moreover, these changes are related to increased cerebral ammonia, alterations in neurometabolite and neurotransmitter concentrations and cortical excitability in HE patients.

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

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

Minimal Hepatic Encephalopathy and Mild Cognitive Impairment Worsen Quality of Life in Elderly Patients With Cirrhosis

BACKGROUND & AIMS

Patients with cirrhosis are growing older. The overlap between minimal hepatic encephalopathy (MHE) and predementia mild cognitive impairment (MCI) could affect quality of life (QOL). We investigated the performance of elderly patients with cirrhosis on tests for MHE and MCI and their effects on QOL.

METHODS

We recruited outpatients with cirrhosis (n = 109) and without cirrhosis (controls, n = 100), 65 years or older, at 4 centers (derivation cohort). All study participants were assessed for psychometric hepatic encephalopathy score (PHES), EncephalApp score, and QOL. MCI was tested in patients with cirrhosis using the repeatable battery for assessment of neuropsychological status and assigned to the following groups: unimpaired, MCI only, MHE only, and MCI+MHE. We created adjusted norms to detect MHE using PHES and EncephalApp scores from the controls. Findings were validated using data from a separate cohort of 77 patients with cirrhosis (mean age, 69.49 ± 4.36 y; 72% men) at the same study sites.

RESULTS

Controls were older but were more educated, performed better cognitively, and had better QOL. Among patients with cirrhosis, age, education, model for end-stage liver disease score, EncephalApp score, and QOL were similar, but PHES and repeatable battery for assessment of neuropsychological status differed among sites. In the derivation cohort, the presence of MHE, with or without MCI, was associated with poor QOL, which was lowest in the MCI+MHE group. When we adjusted for age, sex, and education, 49% of patients with cirrhosis had MHE based on the EncephalApp and 8% had MHE based on the PHES. A similar pattern (49% MHE based on EncephalApp and 6% MHE based on PHES) was found in a validation cohort.

CONCLUSIONS

In a multicenter study of patients with cirrhosis (>65 y) and controls, the presence of MHE, regardless of MCI, was associated with poor cognition and QOL. We created adjusted norms that defined the high sensitivity of EncephalApp for the detection of MHE in older individuals and validated it in a separate cohort.

Novel computerized psychometric tests as primary screening tools for the diagnosis of minimal hepatic encephalopathy

Minimal hepatic encephalopathy (MHE) is a critical neurocognitive complication of decompensated liver cirrhosis and portosystemic shunting, which results in a wide range of cognitive deficits including impairments in working attention, psychomotor speed, and executive function. Current guidelines have recommended paper-and-pencil psychometric tests for the diagnosis of MHE. Most high-risk cirrhotic patients are required to be examined; however, paper-and-pencil psychometric tests are neither convenient nor rapid to perform in the clinic. Recently, novel computerized psychometric tests, including the inhibitory control test, EncephalApp Stroop App, and critical flicker frequency, have been proven to be rapid, effective, and convenient methods for screening MHE in clinical practice and for identifying high-risk cirrhotic patients for further validation using rigid neuropsychometric examinations. However, diagnostic accuracy of these tests is influenced by educational background, age, and cultural differences. This review summarizes clinical evidence of the application of novel computerized psychometric tests for screening MHE.

Impaired brain function improved by L-carnitine in patients with cirrhosis: evaluation using near-infrared spectroscopy

To evaluate the effects of l-carnitine on impaired brain function in patients with liver cirrhosis. We conducted a retrospective cohort study that included sequential 80 liver cirrhosis patients with impaired brain function evaluated using near-infrared spectroscopy (NIRS). Among them, l-carnitine was administered to 48 patients. The NIRS data and blood ammonia level at baseline and after 8 weeks of treatment were compared between patients administered with l-carnitine (l-carnitine group) and those who were not (control group). The NIRS data at baseline were similar between the l-carnitine and control groups (0.04 ± 0.04 vs. 0.04 ± 0.05 mMmm, p = n.s), whereas those in the l-carnitine group (n = 48) were significantly better than that of the control group at 8 weeks of treatment (n = 32) (0.103 ± 0.081 vs. 0.040 ± 0.048 mMmm, p < 0.001). In the l-carnitine group, 35.4% (17/48) of patients had hyperammonemia. The NIRS data of the l-carnitine group at 8 weeks of treatment were significantly improved than that of the control group, irrespective of baseline ammonia levels (0.11 ± 0.09 vs. 0.04 ± 0.05 mMmm, p = 0.005, and 0.10 ± 0.06 vs. 0.02 ± 0.03 mMmm, p = 0.003, for normal baseline ammonia and elevated ammonia levels, respectively). In the multivariate analysis, l-carnitine administration (odds ratio [OR] 3.51, 95% confidence interval [CI] 1.23–9.99, p = 0.019) and baseline NIRS data of ≤ 0.07 mMmm (OR 5.21, 95% CI 1.69–16.0, p = 0.0041) were found as independent significant factors. l-carnitine improves impaired brain function in patients with liver cirrhosis.

Clinical Usefulness of the Inhibitory Control Test (ICT) in the Diagnosis of Minimal Hepatic Encephalopathy

Background: Minimal hepatic encephalopathy (MHE) refers to a number of neuropsychiatric and neurophysiological disorders in patients with cirrhosis who do not show abnormalities on physical examination or in clinical tests. The aim of this study was to determine the prevalence, risk factors, and predictive value of minimal hepatic encephalopathy and the usefulness of the inhibitory control test (ICT) in the diagnosis. Methods: Seventy patients (mean age 53 years, range 24−77) with liver cirrhosis were enrolled in the study. MHE was diagnosed based on PHES (psychometric hepatic encephalopathy score) and ICT. PHES and ICT were validated in a group of 56 control subjects. Results: Minimal hepatic encephalopathy was diagnosed using PHES in 21 patients (30%). ICT diagnosed MHE in 30 patients (42%), and the test had a sensitivity of 65% and a specificity of 57% compared to PHES. The ICT score (lures/target accuracy rate) correlated with the age of subjects (R = 0.35, p = 0.002) and only slightly with education (education in years R = −0.22, p = 0.06). MHE diagnosed with PHES or ICT was associated with a significantly higher model of end-stage liver disease (MELD) score in the follow-up. MHE diagnosed with ICT was correlated with a significantly higher incidence of symptoms of decompensated cirrhosis (p = 0.02) in the follow-up. Conclusions: ICT had moderate sensitivity and specificity in diagnosing MHE compared to PHES. Importantly, MHE detected with PHES or ICT was associated with poorer survival and a more severe progression of the disease.

Minimal Hepatic Encephalopathy

Minimal hepatic encephalopathy, previously called subclinical hepatic encephalopathy, represents the earliest and mildest form of hepatic encephalopathy. It is the most under-recognized and underdiagnosed form of hepatic encephalopathy. Although there is no diagnostic gold standard, validated testing modalities have been devised to detect this neurocognitive complication. The newest developments include medically related apps for smartphones or tablets that can be easily used to diagnose and monitor minimal hepatic encephalopathy. Although recognition of this neurocognitive impairment can be challenging, early detection is paramount with the discovery of an association with worse clinical outcomes in patients diagnosed with minimal hepatic encephalopathy.

Oral glutamine challenge is a marker of altered ammonia metabolism and predicts the risk of hepatic encephalopathy

BACKGROUND

The current therapies for hepatic encephalopathy (HE) are not completely effective in all patients, probably due to the physiopathological heterogeneity and the different conditions underlying the bout of HE. We hypothesized that oral glutamine challenge (OGC) is able to predict the risk of HE through the identification of various features and types of HE.

METHODS

We included 238 cirrhotic patients (198 without and 40 with a previous HE episode) that underwent OGC, obtaining baseline and 60 minutes post-load ammonia levels. Combined evaluation of baseline hyperammonemia (>78 mcg/dL) and impaired OGC (Δ >32 mcg/dL) defined low-, intermediate- and high-risk groups. Patients were censored at HE, liver transplantation and death or 6 years of follow-up.

RESULTS

The 28.3% (56/198) of the main cohort suffered from HE during the follow-up. In the competing risk analysis, both intermediate- (subhazard ratio (sHR) 2.01 (95% CI 1.00-4.14); P = .048) and high-risk groups (sHR 4.67 (95% CI 2.19-9.98); P = .0001) were associated with the first HE episode, together with age and albumin. Similar results were found for repeated HE events. The cumulative incidence for HE of the high-risk group was two and four times greater than the intermediate- and low-risk groups, respectively. The HE grade was also higher in individuals with the greatest risk (P = .035). The most common precipitant factor was diuretics in the high-risk group, while infections and electrolyte imbalance predominated in the rest of patients.

CONCLUSION

Oral glutamine challenge identified patients at risk of HE and defined specific features of the episodes. This tool could be useful in the decision-making process for the adequate management of HE.

Brain function and metabolism in patients with long-term tacrolimus therapy after kidney transplantation in comparison to patients after liver transplantation

Background

About 50% of the patients 5–7 years after kidney transplantation show impairment of memory, attention and executive function. Tacrolimus frequently induces neurological complications in the first few weeks after transplantation. Furthermore, tacrolimus treatment is associated with impaired cognitive function in the long-term in patients after liver transplantation. We hypothesize that long-term tacrolimus therapy is associated with cognitive dysfunction and alterations of brain structure and metabolism in patients after kidney transplantation.

Methods

Twenty-one patients 10 years after kidney transplantation underwent cognitive testing, magnetic resonance imaging and whole brain 31-phosphor magnetic resonance spectroscopy for the assessment of brain function, structure and energy metabolism. Using a cross-sectional study design the results were compared to those of patients 1 (n = 11) and 5 years (n = 10) after kidney transplantation, and healthy controls (n = 17). To further analyze the share of transplantation, tacrolimus therapy and kidney dysfunction on the results patients after liver transplantation (n = 9) were selected as a patient control group.

Results

Patients 1 and 10 years after kidney transplantation (p = 0.02) similar to patients 10 years after liver transplantation (p<0.01) showed significantly worse cognitive function than healthy controls. In contrast to patients after liver transplantation patients after kidney transplantation showed significantly reduced adenosine triphosphate levels in the brain compared to healthy controls (p≤0.01). Patients 1 and 5 years after kidney transplantation had significantly increased periventricular hyperintensities compared to healthy controls (p<0.05).

Conclusions

Our data indicate that cognitive impairment in the long-term after liver and kidney transplantation cannot exclusively be explained by CNI neurotoxicity.

Advances in psychometric tests for screening minimal hepatic encephalopathy: From paper-and-pencil to computer-aided assessment

Minimal hepatic encephalopathy (MHE) is a major neuropsychiatric complication of liver cirrhosis and portosystemic shunting. Although MHE produces a spectrum of cognitive impairments in the domains of short-term attention, working memory, and executive function, it generally does not present with obvious clinical manifestation on conventional assessments. Paper-and-pencil psychometric tests, such as the psychometric hepatic encephalopathy score and the repeatable battery for the assessment of neuropsychological status, are recommended to diagnose MHE. However, these tests are neither rapid nor convenient to use in practice. To facilitate repeated testing in clinic and follow-up, computer-aided psychometric tests, such as the scan test, Cognitive Drug Research assessment battery, inhibitory control test, EncephalApp Stroop App, and critical flicker frequency, have been used to screen for MHE among patients with liver cirrhosis. The aim of this review was to describe the progression from the utility of paper-and-pencil to computer-aided psychometric tests for MHE screening in clinical practice.

Hepatic Encephalopathy Is Reversible in the Long Term After Liver Transplantation

Cognitive dysfunction caused by hepatic encephalopathy (HE) improves within the first year after liver transplantation (LT). However, cognitive restitution seems to be incomplete in a subset of patients and after LT a new-onset cognitive decline was described. Data about the longterm development of cognitive function after liver transplantation (LT) are sparse. This prospective study analyzed whether a history of hepatic encephalopathy (HE) before LT had an impact on the longterm outcome of cognitive function after LT and if patients who underwent LT 5 years earlier showed worse cognitive function than healthy controls. The cognitive function of 34 patients was assessed before LT and at 1 year and 5 years after LT by psychometric tests, including the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and the portosystemic encephalopathy syndrome test, which provides the psychometric hepatic encephalopathy score (PHES). Furthermore, patients completed surveys to assess health-related quality of life (HRQOL). An 22 additional patients were included after LT. Patients were subdivided by having a history of HE before LT. The control group consisted of 55 healthy patients adjusted for age and education. Before LT, patients performed significantly worse than controls in the psychometric tests: RBANS Total Scale (TS), mean ± standard deviation (SD), 92.6 ± 13.3 versus 99.9 ± 12.0, P = 0.01; and PHES, median (interquartile range [IQR]), 0 (-3 to 1) versus 1 (0-2), P < 0.001. At 1 year after LT, patients with a history of HE still showed cognitive impairment compared with controls: RBANS TS, mean ± SD, 89.8 ± 15.1 versus 99.9 ± 12.0, P < 0.01; and PHES, median (IQR), 0 (-2 to 1.25) versus 1 (0-2), P = 0.03. At 5 years after LT, patients with and without a history of HE showed normal cognitive function and improved HRQOL. In conclusion, HE-associated cognitive impairment seems to be reversible within 5 years after LT.

Impact of immunosuppressive therapy on brain derived cytokines after liver transplantation

BACKGROUND

While acute neurotoxic side effects of calcineurin inhibitors (CNI) are well-known, data upon long-term effects on brain structure and function are sparse. We hypothesize that long-term CNI therapy affects the neuroimmune system, thereby, increasing the risk of neurodegeneration. Here, we measured the impact of CNI therapy on plasma levels of brain- and T cell-derived cytokines in a cohort of patients after liver transplantation (LT).

METHODS

Levels of T cell-mediated cytokines (e.g. Interferon-γ (IFN-γ)) and brain-derived cytokines (e.g. brain derived neurotrophic factor (BDNF), platelet derived growth factor (PDGF)) were measured by multiplex assays in plasma of 82 patients about 10 years after LT (17 with CNI free, 35 with CNI low dose, 30 with standard dose CNI immunosuppression) and 33 healthy controls. Data were related to psychometric test results and parameters of cerebral magnetic resonance imaging.

RESULTS

IFN-γ levels were significantly higher in the CNI free LT patient group (p=0.027) compared to healthy controls. BDNF levels were significantly lower in LT patients treated with CNI (CNI low: p<0.001; CNI standard: p=0.016) compared to controls. PDGF levels were significantly lower in the CNI low dose group (p=0.004) and for PDGF-AB/BB also in the CNI standard dose group (p=0.029) compared to controls. BDNF and PDGF negatively correlated with cognitive function and brain volume (p<0.05) in the CNI low dose group.

CONCLUSION

Our results imply that long-term treatment with CNI suppresses BDNF and PDGF expression, both crucial for neuronal signaling, cell survival and synaptic plasticity and thereby may lead to cognitive dysfunction and neurodegeneration.

Cognitive decline on the Repeatable Battery for the Assessment of Neuropsychological Status in progressive supranuclear palsy

Objective: Progressive supranuclear palsy (PSP) is associated with a variety of cognitive deficits, but few studies have reported on its cognitive trajectory across time, especially on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS).Methods: Two hundred twenty participants diagnosed with Richardson's syndrome of PSP (PSP-RS) were evaluated with the RBANS at baseline, six months, and one year with alternate forms.Results: When using dependent t-tests, significant declines were observed on all Indexes of the RBANS from baseline to six months (ps < 0.01). Between six months and one year, significant declines were observed on three Indexes of the RBANS (ps < 0.05). Using existing regression-based change formulae from cognitively intact older adults, these participants with PSP showed significant decline on all RBANS Indexes (ps < 0.01) across one year. Finally, new regression-based change formulae were developed on this sample of individuals with PSP-RS to more precisely evaluate cognitive change in this condition.Conclusion: In this large, longitudinal cohort of participants with PSP-RS, many (but not all) showed notable cognitive decline across six months and one year on the RBANS. The different methods of examining change across time yielded different results, with regression-based methods appearing to more accurately capture decline in this sample. These findings are expected to allow clinicians to more accurately evaluate cognitive trajectories in patients with PSP, as well as make better estimates of prognosis and offer more appropriate treatment recommendations. Such findings are also expected to inform clinical trials as to the changes in cognitive outcomes with this neurological condition.

Quantitative magnetic resonance imaging indicates brain tissue alterations in patients after liver transplantation

PURPOSE

To investigate cerebral microstructural alterations in patients treated with calcineurin inhibitors (CNI) after orthotopic liver transplantation (OLT) using quantitative magnetic resonance imaging (qMRI) and a cross-sectional study design.

METHODS

Cerebral qMRI was performed in 85 patients in a median 10 years after OLT compared to 31 healthy controls. Patients were treated with different dosages of CNI or with a CNI-free immunosuppression (CNI-free: n = 19; CNI-low: n = 36; CNI-standard: n = 30). T2-, T2*- and T2'- relaxation times, as well as apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were measured in brain gray and white matter by using the regions of interest method.

RESULTS

In comparison to controls, patients revealed significantly increased T2, T2*, T2', ADC and reduced FA, predominantly in the frontal white matter, indicating microstructural brain alterations represented by increased free water (increased T2), reduced neuronal metabolism (increased T2') and a lower degree of spatial organization of the nervous fibers (reduced FA). CNI-low and CNI-free patients showed more alterations than CNI-standard patients. Analysis of their history revealed impairment of kidney function while under standard CNI dose suggesting that these patients may be more vulnerable to toxic CNI side-effects.

CONCLUSION

Our findings suggest that the individual sensitivity to toxic side effects should be considered when choosing an appropriate immunosuppressive regimen in patients after liver transplantation.

Specific Gut and Salivary Microbiota Patterns Are Linked With Different Cognitive Testing Strategies in Minimal Hepatic Encephalopathy

OBJECTIVES

Minimal hepatic encephalopathy (MHE) is epidemic in cirrhosis, but testing strategies often have poor concordance. Altered gut/salivary microbiota occur in cirrhosis and could be related to MHE. Our aim was to determine microbial signatures of individual cognitive tests and define the role of microbiota in the diagnosis of MHE.

METHODS

Outpatients with cirrhosis underwent stool collection and MHE testing with psychometric hepatic encephalopathy score (PHES), inhibitory control test, and EncephalApp Stroop. A subset provided saliva samples. Minimal hepatic encephalopathy diagnosis/concordance between tests was compared. Stool/salivary microbiota were analyzed using 16srRNA sequencing. Microbial profiles were compared between patients with/without MHE on individual tests. Logistic regression was used to evaluate clinical and microbial predictors of MHE diagnosis.

RESULTS

Two hundred forty-seven patients with cirrhosis (123 prior overt HE, MELD 13) underwent stool collection and PHES testing; 175 underwent inhibitory control test and 125 underwent Stroop testing. One hundred twelve patients also provided saliva samples. Depending on the modality, 59%-82% of patients had MHE. Intertest Kappa for MHE was 0.15-0.35. Stool and salivary microbiota profiles with MHE were different from those without MHE. Individual microbiota signatures were associated with MHE in specific modalities. However, the relative abundance of Lactobacillaceae in the stool and saliva samples was higher in MHE, regardless of the modality used, whereas autochthonous Lachnospiraceae were higher in those without MHE, especially on PHES. On logistic regression, stool and salivary Lachnospiraceae genera (Ruminococcus and Clostridium XIVb) were associated with good cognition independent of clinical variables.

DISCUSSION

Specific stool and salivary microbial signatures exist for individual cognitive testing strategies in MHE. The presence of specific taxa associated with good cognitive function regardless of modality could potentially be used to circumvent MHE testing.

Cognitive deficits in progressive supranuclear palsy on the Repeatable Battery for the Assessment of Neuropsychological Status

Progressive supranuclear palsy (PSP) is associated with a variety of cognitive deficits, as well as motor and psychiatric disturbances. As clinical trials for PSP evolve, briefer screening instruments will be needed to determine cognitive effects of interventions. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) may fill this gap. Three hundred four participants diagnosed with Richardson's syndrome of PSP were evaluated with the RBANS, as well as other scales typically used in PSP. RBANS performances for these participants fell significantly below expectations for the Total Scale score and all five Indexes. Cognitive scores on the RBANS were also significantly related to other markers of PSP (e.g., motor and functional abilities, depression, global cognition). Compared to other clinical conditions from the literature, patients with PSP show impairment on tests of visuospatial perception and construction and attention. Although additional research is needed, the current study supports the clinical applicability of the RBANS in patients with PSP, as well as its potential for future clinical trials.

Brain metabolic alterations in patients with long-term calcineurin inhibitor therapy after liver transplantation

BACKGROUND

Calcineurin inhibitor (CNI) neurotoxicity after liver transplantation might be due to impairment of the cerebral metabolism.

AIMS

To investigate CNI-related alterations of brain metabolite distributions and associations between cognitive function and brain metabolism in patients with long-term CNI treatment after liver transplantation.

METHODS

Eighty-two patients (19 CNI free, 34 CNI low-dose and 29 standard-dose CNI immunosuppression) 10 years after liver transplantation and 32 adjusted healthy controls underwent nonlocalised brain phosphorus magnetic resonance spectroscopy (MRS) and single voxel proton MRS in the parietal white matter to estimate brain metabolite contents. The MRS results were correlated with psychometric data assessing cognitive function.

RESULTS

Phosphorus metabolite concentrations with the exception of phosphocreatine (PCr) were reduced in patients compared to controls. Particularly, patients with low-dose CNI therapy showed a significant decrease in adenosine triphosphate (0.209 ± 0.012 vs 0.222 ± 0.010; P < 0.001) and a significant increase in PCr (0.344 ± 0.026 vs 0.321 ± 0.017; P < 0.001) compared to controls. Myo-Inositol in the CNI free group (2.719 ± 0.549 institutional unit [iu]) was significantly lower compared to controls (3.181 ± 0.425 iu; P = 0.02), patients on low-dose (3.130 ± 0.513 iu; P < 0.05) and standard-dose CNI therapy (3.207 ± 0.632 iu; P < 0.02). Glutamate and glutamine levels correlated negatively with cognitive function (Repeatable Battery for the Assessment of Neuropsychological Status Total Scale: R = -0.362, P = 0.029).

CONCLUSION

Long-term CNI therapy after liver transplantation might be associated with alterations of brain metabolites.

Updates on the pathophysiology and therapeutic targets for hepatic encephalopathy

PURPOSE OF REVIEW

Hepatic encephalopathy is one of the most debilitating clinical manifestations of cirrhosis and associated with increased morbidity and mortality. Treatment modalities available include the nonabsorbable disaccharides (lactulose) and the nonabsorbable antibiotics (rifaximin).

RECENT FINDINGS

Newer therapeutic targets under evaluation include ammonia scavengers (ornithine phenylacetate) and modulation of gut microbiota (fecal microbiota transplantation).

SUMMARY

This review will focus on the pathophysiology of hepatic encephalopathy along with an update on therapeutic targets under investigation.

Microstructural brain abnormalities correlate with neurocognitive dysfunction in minimal hepatic encephalopathy: a diffusion kurtosis imaging study

PURPOSE

To investigate the diffusion kurtosis imaging (DKI) in early minimal hepatic encephalopathy (MHE) diagnosis and evaluate the correlations between changes in DKI metrics and cognitive performance.

METHODS

We enrolled 116 cirrhosis patients, divided into non-HE (n = 61) and MHE (n = 55), and 46 normal controls (NCs). All patients underwent cognitive testing before magnetic resonance imaging. DKI metrics were calculated through whole-brain voxel-based analysis (VBA) and differences between the groups were assessed. Pearson correlation between the DKI metrics and cognitive performance was analysed. The receiver operating characteristic (ROC) curve was used to analyse the diagnostic efficiency of DKI metrics for MHE.

RESULTS

MHE patients had significantly altered DKI metrics in a wide range of regions; lower fractional anisotropy (FA) and higher mean diffusivity (MD) are mainly located in the corpus callosum, left temporal white matter (WM), and right medial frontal WM. Furthermore, significantly altered kurtosis metrics included lower mean kurtosis (MK) in the corpus callosum and left thalamus, lower radial kurtosis (RK) in the corpus callosum, and lower axial kurtosis (AK) in the right anterior thalamic radiation. Alterations in axial diffusivity (AD), radial diffusivity (RD), and MD were closely correlated with cognitive scores. The ROC curves indicated AD in the forceps minor had the highest predictive performance for MHE in the cirrhosis patients (area under curve = 0.801, sensitivity = 77.05%, specificity = 74.55%).

CONCLUSIONS

Altered DKI metrics indicate brain microstructure abnormalities in MHE patients, some of which may be used as neuroimaging markers for early MHE diagnosis.

Cognitive impairment after liver transplantation: residual hepatic encephalopathy or posttransplant encephalopathy?

Liver transplantation (LT) represents the definitive treatment for end-stage liver disease. Cognitive impairment following LT is frequent, referred to as postliver transplant encephalopathy (PLTE). LT removes the underlying chronic liver disease, and until recently hepatic encephalopathy (HE) was assumed to be fully reversible after LT. However, increasing evidence indicates that some degree of cognitive impairment may be present after LT. To which extent PLTE reflects cognitive impairment caused by residual HE (RHE) or the combined effect of other factors affecting brain function before, during, and after LT is not clarified. None of the available psychometric and neurophysiological tests used for detecting HE is shown to be able to distinguish between etiologies. The available, mostly retrospective, clinical studies indicate a high prevalence of abnormal psychometric tests after LT, and not all seem to recover completely. The patients with earlier HE show the most marked improvements, suggesting that the clinical picture of the early PLTE, in fact, represents RHE. Other early post-LT etiologies for PLTE comprise cerebral ischemia, critical illness encephalopathy, and immunosuppressive therapy. Late-onset etiologies comprise diabetes and hypertension, among others. PLTE regardless of etiology is a worrying issue and needs more attention in the form of mechanistic research, development of diagnostic/discriminative tools, and standardized prospective clinical studies.

Validation of the simplified Animal Naming Test as primary screening tool for the diagnosis of covert hepatic encephalopathy

BACKGROUND

Diagnosis of covert hepatic encephalopathy (CHE) is time consuming in clinical practice. Recently, a new diagnostic tool - the simplified Animal Naming Test (S-ANT1) - was presented with promising results in an Italian cohort. The aim of the present study was to validate S-ANT1 in a cohort of cirrhotic patients from a German tertiary referral centre.

METHODS

143 cirrhotic patients and 37 healthy controls were enrolled. Hepatic encephalopathy (HE) grade 1 (HE1) was clinically diagnosed according to the West-Haven Criteria. Critical flicker frequency and Psychometric Hepatic Encephalopathy Score were used to detect minimal HE (MHE). All participants were additionally examined by S-ANT1.

RESULTS

58 (40.6%) patients presented with CHE (40 MHE, 18 HE1). S-ANT1 was lowest in patients with HE1, followed by patients with MHE, patients without CHE, and healthy controls, respectively (each p < 0.05). Naming <20 animals discriminated best between patients with and without CHE in ROC analysis (with Youden's index). With a cut-off value of ≥23 mentioned animal names further testing for CHE could be avoided in 38.5% of patients with a negative predictive value of 84%.

CONCLUSIONS

S-ANT1 may become an important first screening tool for the assessment of CHE in clinical practice.

Hepatic Encephalopathy: Definition, Clinical Grading and Diagnostic Principles

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

Diagnosis of Minimal Hepatic Encephalopathy: A Systematic Review of Point-of-Care Diagnostic Tests

OBJECTIVES

Minimal hepatic encephalopathy (HE) is common, characterized by deficits in reaction time and executive function, and strongly associated with disability and mortality. Point-of-care diagnostics performed without specialized skills or equipment are now available, albeit with limited data regarding their generalizability.

METHODS

We systematically reviewed MEDLINE, EMBASE, Cochrane Library, and Scopus for diagnostic studies of MHE using broad search terms including HE and minimal, covert, or the names of published diagnostic modalities. We included tests that provide results during clinical visits without requiring neuropsychologists to administer and/or special equipment. These include the Inhibitory Control Test (ICT, n=16), EncephalApp Stroop (n=3), an algorithm based on the Sickness Impact Profile (n=2), and the Animal Naming Test (ANT, n=1).

RESULTS

The populations enrolled in the included study were highly selected, excluding patients with recent (6-months) alcohol or psychoactive medications use. Cutoffs for MHE for each test varied widely. For the ICT, the optimal cutoffs for MHE varied by 300%, whereas healthy control performance varied >400%. The optimal cutoffs for the EncephalApp also varied (by 50%). The gold standards for MHE varied substantially between studies, and clinical outcomes were never used to develop test cutoffs. Data comparing the performance of each modality are lacking. Longitudinal data are limited but suggest that good performance on the ICT, EncephalApp or ANT is associated with reduced risk of developing overt HE.

CONCLUSION

The point-of-care tests for MHE are promising tools. However, additional longitudinal studies are needed in clinically representative populations of at-risk patients with cutoffs validated based on the development of clinical outcomes.

Longterm calcineurin inhibitor therapy and brain function in patients after liver transplantation

Calcineurin inhibitors (CNIs) frequently induce neurological complications early after orthotopic liver transplantation (OLT). We hypothesize that longterm CNI therapy after OLT causes dose-dependent cognitive dysfunction and alteration of brain structure. In this study, 85 OLT patients (20 with CNI-free, 35 with CNI low-dose, and 30 with standard-dose CNI immunosuppression) underwent psychometric testing and cerebral magnetic resonance imaging approximately 10 years after OLT to assess brain function and structural brain alterations. A total of 33 healthy patients adjusted for age, sex, and education served as controls. Patients receiving CNI showed a significantly worse visuospatial/constructional ability compared with controls (P ≤ 0.04). Furthermore, patients on low-dose CNI therapy had an overall impaired cognitive function compared with controls (P = 0.01). The tacrolimus total dose and mean trough level were negatively correlated to cognitive function. CNI doses had been adjusted in 91% of the patients in the low-dose and CNI-free groups in the past due to CNI-induced kidney damage. Patients treated with CNI showed significantly more white matter hyperintensities (WMH) than patients on CNI-free immunosuppression and controls (P < 0.05). Both the mean cyclosporine A and tacrolimus trough levels correlated significantly with WMH. In conclusion, longterm CNI therapy carries a risk of cognitive dysfunction especially in patients who already showed nephrotoxic side effects indicating an increased susceptibility of these patients against toxic CNI effects. This subgroup of patients might benefit from a change to CNI-free immunosuppression. Liver Transplantation 24 56-66 2018 AASLD.

The continuous reaction time test for minimal hepatic encephalopathy validated by a randomized controlled multi-modal intervention-A pilot study

BACKGROUND

Minimal hepatic encephalopathy (MHE) is clinically undetectable and the diagnosis requires psychometric tests. However, a lack of clarity exists as to whether the tests are in fact able to detect changes in cognition.

AIM

To examine if the continuous reaction time test (CRT) can detect changes in cognition with anti-HE intervention in patients with cirrhosis and without clinically manifest hepatic encephalopathy (HE).

METHODS

Firstly, we conducted a reproducibility analysis and secondly measured change in CRT induced by anti-HE treatment in a randomized controlled pilot study: We stratified 44 patients with liver cirrhosis and without clinically manifest HE according to a normal (n = 22) or abnormal (n = 22) CRT. Each stratum was then block randomized to receive multimodal anti-HE intervention (lactulose+branched-chain amino acids+rifaximin) or triple placebos for 3 months in a double-blinded fashion. The CRT is a simple PC-based test and the test result, the CRT index (normal threshold > 1.9), describes the patient's stability of alertness during the 10-minute test. Our study outcome was the change in CRT index in each group at study exit. The portosystemic encephalopathy (PSE) test, a paper-and-pencil test battery (normal threshold above -5), was used as a comparator test according to international guidelines.

RESULTS

The patients with an abnormal CRT index who were randomized to receive the active intervention normalized or improved their CRT index (mean change 0.92 ± 0.29, p = 0.01). Additionally, their PSE improved (change 3.85 ± 1.83, p = 0.03). There was no such effect in any of the other study groups.

CONCLUSION

In this cohort of patients with liver cirrhosis and no manifest HE, the CRT identified a group in whom cognition improved with intensive anti-HE intervention. This finding infers that the CRT can detect a response to treatment and might help in selecting patients for treatment.

The animal naming test: An easy tool for the assessment of hepatic encephalopathy

Screening for hepatic encephalopathy (HE) that does not cause obvious disorientation or asterixis (minimal HE [MHE]/grade 1 HE) is important. We examined if the animal naming test (ANT₁ ) (maximum number of animals listed in 1 minute) is useful in this context. In total, 208 healthy controls, 40 controls with inflammatory bowel disease, and 327 consecutive patients with cirrhosis underwent the ANT₁ . Patients were tested for MHE by the psychometric HE score, and 146 were assessed by electroencephalography; 202 patients were followed up regarding the occurrence of overt HE and death. In the healthy controls, ANT₁ was influenced by limited education (<8 years) and advanced age (>80 years, P < 0.001). Using an age and education adjusting procedure, the simplified ANT₁ (S-ANT₁ ) was obtained. An S-ANT₁ of <10 animals was abnormal. Of the patients, 169 were considered unimpaired, 32 as having HE ≥grade 2, and 126 as having MHE/grade 1 HE. This group had lower S-ANT₁ than unimpaired patients (12 ± 0.4 versus 16 ± 0.7, P < 0.001) and higher S-ANT₁ than those with HE ≥grade 2 (4 ± 0.9). In grade 1 HE the S-ANT₁ was lower than in MHE. Following receiver operating characteristic analysis (Youden's index), 15 animals produced the best discrimination between unimpaired and MHE/grade 1 HE patients. Thus, a three-level score (0 for S-ANT₁ ≥15, 1 for 10 ≤ S-ANT₁ < 15, 2 for S-ANT₁ <10) was obtained. This score was correlated both to the psychometric HE score (P < 0.0001) and to electroencephalography (P = 0.007). By sample random split validation, both S-ANT₁ and its three-level score showed prognostic value regarding the 1-year risk of overt HE and death. No inflammatory bowel disease control had S-ANT <15.

CONCLUSION

The S-ANT₁ is an easily obtainable measure useful for the assessment of HE. (Hepatology 2017;66:198-208).

Hepatic Encephalopathy: An Update on the Pathophysiology and Therapeutic Options

Hepatic encephalopathy is a spectrum of reversible neuropsychiatric abnormalities, seen in patients with liver dysfunction and/or portosystemic shunting. One of the most debilitating complications of cirrhosis, encephalopathy affects 30-45% of cirrhotics. In addition to significantly affecting the lives of patients and their caregivers, it is also associated with increased morbidity and mortality as well as significant utilization of health care resources. In this paper, we provide an overview on the pathophysiology, diagnosis, management and newer therapies of hepatic encephalopathy.

Hepatic encephalopathy before and neurological complications after liver transplantation have no impact on the employment status 1 year after transplantation

AIM

To investigate the impact of hepatic encephalopathy before orthotopic liver transplantation (OLT) and neurological complications after OLT on employment after OLT.

METHODS

One hundred and fourteen patients with chronic liver disease aged 18-60 years underwent neurological examination to identify neurological complications, neuropsychological tests comprising the PSE-Syndrome-Test yielding the psychometric hepatic encephalopathy score, the critical flicker frequency and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), completed a questionnaire concerning their occupation and filled in the short form 36 (SF-36) to assess health-related quality of life before OLT and 12 mo after OLT, if possible. Sixty-eight (59.6%) patients were recruited before OLT, while on the waiting list for OLT at Hannover Medical School [age: 48.7 ± 10.2 years, 45 (66.2%) male], and 46 (40.4%) patients were included directly after OLT.

RESULTS

Before OLT 43.0% of the patients were employed. The patients not employed before OLT were more often non-academics (employed: Academic/non-academic 16 (34.0%)/31 vs not employed 10 (17.6%)/52, P = 0.04), had more frequently a history of hepatic encephalopathy (HE) (yes/no; employed 15 (30.6%)/34 vs not employed 32 (49.2%)/33, P = 0.05) and achieved worse results in psychometric tests (RBANS sum score mean ± SD employed 472.1 ± 44.5 vs not employed 443.1 ± 56.7, P = 0.04) than those employed. Ten patients (18.2%), who were not employed before OLT, resumed work afterwards. The patients employed after OLT were younger [age median (range, min-max) employed 47 (42, 18-60) vs not employed 50 (31, 29-60), P = 0.01], achieved better results in the psychometric tests (RBANS sum score mean ± SD employed 490.7 ± 48.2 vs not employed 461.0 ± 54.5, P = 0.02) and had a higher health-related quality of life (SF 36 sum score mean ± SD employed 627.0 ± 138.1 vs not employed 433.7 ± 160.8; P < 0.001) compared to patients not employed after OLT. Employment before OLT (P < 0.001), age (P < 0.01) and SF-36 sum score 12 mo after OLT (P < 0.01) but not HE before OLT or neurological complications after OLT were independent predictors of the employment status after OLT.

CONCLUSION

HE before and neurological complications after OLT have no impact on the employment status 12 mo after OLT. Instead younger age and employment before OLT predict employment one year after OLT.

Adventures in Developing an App for Covert Hepatic Encephalopathy

Patient-reported outcomes (PRO) are critical to understand the spectrum of disease in chronic conditions but are often ignored in clinical practice. Cirrhosis, one of the leading causes of morbidity, is associated with severely impaired PROs likely due to covert hepatic encephalopathy (CHE). The clinical relevance and logistic barriers to routine CHE testing led us to develop the “EncephalApp Stroop App”, which is now being used to diagnose CHE. The Primer discusses this example which can potentially be applied to other diseases.

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

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

Qualifying and quantifying minimal hepatic encephalopathy

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

Stepwise diagnosis in covert hepatic encephalopathy: critical flicker frequency and MELD-score as a first-step approach

BACKGROUND

The diagnosis of covert hepatic encephalopathy (CHE) by means of portosystemic encephalopathy syndrome (PSE) test is costly and therefore infrequently performed.

AIM

To determine the ability of critical flicker frequency (CFF) alone or in combination with laboratory findings, as an initial test to pre-select which patients should undergo further testing for the diagnosis of covert hepatic encephalopathy.

METHODS

This single-centre study included all patients with cirrhosis who underwent PSE and CFF in 2011. CHE was defined by abnormal PSE test. Logistic regression analysis was performed to identify predictors of CHE. ROC curves were used to identify cut-offs of these independent predictors.

RESULTS

One hundred and seventeen patients were included. Seventy (60%) had CHE with a higher MELD [16 (IQR 13-21); P = 0.001] and lower CFF [38 Hz (IQR 36-41) P = 0.0011]. On multivariate analyses, CFF [OR 0.83 (95% CI 0.74-0.94)] and MELD [OR 1.13 (95% CI 1.04-1.22)] were identified as independent predictors of CHE. Sensitivity and specificity of a CFF cut-off of 43 Hz was 93.5% and 42.9%, and for a MELD cut-off of 24, it was 97.5% and 32.8% respectively. Most patients with a MELD-Score <24 and a CFF >43 Hz did not have CHE (78%) and with a MELD-Score >24 and CFF <43 Hz most patients had CHE (85%). Therefore, 27% of patients could avoid further testing with a diagnostic accuracy of 81%.

CONCLUSION

The combination of MELD-score and critical flicker frequency may be used as a first diagnostic step to filter patients, in whom further covert hepatic encephalopathy testing could be avoided.

Effects of common chronic medical conditions on psychometric tests used to diagnose minimal hepatic encephalopathy

Many chronic medical conditions are accompanied by cognitive disturbances but these have only to a very limited extent been psychometrically quantified. An exception is liver cirrhosis where hepatic encephalopathy is an inherent risk and mild forms are diagnosed by psychometric tests. The preferred diagnostic test battery in cirrhosis is often the Continuous Reaction Time (CRT) and the Portosystemic Encephalopathy (PSE) tests but the effect on these of other medical conditions is not known. We aimed to examine the effects of common chronic (non-cirrhosis) medical conditions on the CRT and PSE tests. We studied 15 patients with heart failure (HF), 15 with end stage renal failure (ESRF), 15 with dysregulated type II diabetes (DMII), 15 with chronic obstructive pulmonary disease (COPD), and 15 healthy persons. We applied the CRT test, which is a 10-min computerized test measuring sustained attention and reaction time stability and the PSE test, which is a paper-pencil test battery consisting of 5 subtests. We found that a high fraction of the patients with HF (8/15, 0.002) or COPD (7/15, p = 0.006) had pathological CRT test results; and COPD patients also frequently had an abnormal PSE test result (6/15, p < 0.0001). Both tests were unaffected by ESRF and DMII. Half of the patients with HF or COPD had psychometrically measurable cognitive deficits, whereas those with ESRF or DMII had not. This adds to the understanding of the clinical consequences of chronic heart- and lung disease, and implies that the psychometric tests should be interpreted with great caution in cirrhosis patients with heart- or lung comorbidity.

Diagnosis of Minimal Hepatic Encephalopathy Using Stroop EncephalApp: A Multicenter US-Based, Norm-Based Study

OBJECTIVES

Diagnosing minimal hepatic encephalopathy (MHE) is challenging, and point-of-care tests are needed. Stroop EncephalApp has been validated for MHE diagnosis in single-center studies. The objective of the study was to validate EncephalApp for MHE diagnosis in a multicenter study.

METHODS

Outpatient cirrhotics (with/without prior overt hepatic encephalopathy (OHE)) and controls from three sites (Virginia (VA), Ohio (OH), and Arkansas (AR)) underwent EncephalApp and two gold standards, psychometric hepatic encephalopathy score (PHES) and inhibitory control test (ICT). Age-/gender-/education-adjusted values for EncephalApp based on direct norms, and based on ICT and PHES, were defined. Patients were followed, and EncephalApp cutoff points were used to determine OHE prediction. These cutoff points were then used in a separate VA-based validation cohort.

RESULTS

A total of 437 cirrhotics (230 VA, 107 OH, 100 AR, 36% OHE, model for end-stage liver disease (MELD) score 11) and 308 controls (103 VA, 100 OH, 105 AR) were included. Using adjusted variables, MHE was present using EncephalApp based on norms in 51%, EncephalApp based on PHES in 37% (sensitivity 80%), and EncephalApp based on ICT in 54% of patients (sensitivity 70%). There was modest/good agreement between sites on EncephalApp MHE diagnosis using the three methods. OHE developed in 13% of patients, which was predicted by EncephalApp independent of the MELD score. In the validation cohort of 121 VA cirrhotics, EncephalApp directly and based on gold standards remained consistent for MHE diagnosis with >70% sensitivity.

CONCLUSIONS

In this multicenter study, EncephalApp, using adjusted population norms or in the context of existing gold standard tests, had good sensitivity for MHE diagnosis and predictive capability for OHE development.

Covert and Overt Hepatic Encephalopathy: Diagnosis and Management

Hepatic encephalopathy (HE) is part of a spectrum of neurocognitive changes in cirrhosis. HE is divided into 2 broad categories based on severity: covert hepatic encephalopathy (CHE) and overt hepatic encephalopathy (OHE). CHE has a significant impact on a patient's quality of life, driving performance, and recently has been associated with increased hospitalizations and death. Likewise, OHE is associated with increased rates of hospitalizations and mortality, and poor quality of life. Given its significant burden on patients, care takers, and the health care system, early diagnosis and management are imperative. In addition, focus also should be directed on patient and family member education on the disease progression and adherence to medications. Treatment strategies include the use of nonabsorbable disaccharides, antibiotics (ie, rifaximin), and, potentially, probiotics. Other therapies currently under further investigation include L-ornithine-L-aspartate, ornithine phenylacetate, glycerol phenylbutyrate, molecular adsorbent recirculating system, and albumin infusion.