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

Prevalence of Minimal Hepatic Encephalopathy in Patients With Liver Cirrhosis: A Multicenter Study

INTRODUCTION

The prevalence of minimal hepatic encephalopathy (MHE), in particular in different subgroups, remains unknown. This study aimed to analyze the prevalence of MHE in different subgroups to identify patients at high risk and to pave the way for personalized screening approaches.

METHODS

In this study, data of patients recruited at 10 centers across Europe and the United States were analyzed. Only patients without clinical signs of hepatic encephalopathy were included. MHE was detected using the Psychometric Hepatic Encephalopathy Score (PHES, cut-off < or ≤-4 depending on local norms). Clinical and demographic characteristics of the patients were assessed and analyzed.

RESULTS

In total, 1,868 patients with cirrhosis with a median model for end-stage liver disease (MELD) of 11 were analyzed (Child-Pugh [CP] stages: A 46%, B 42%, and C 12%). In the total cohort, MHE was detected by PHES in 650 patients (35%). After excluding patients with a history of overt hepatic encephalopathy, the prevalence of MHE was 29%. In subgroup analyses, the prevalence of MHE in patients with CP A was low (25%), whereas it was high in CP B or C (42% and 52%). In patients with a MELD score <10, the prevalence of MHE was only 25%, but it was 48% in patients with a MELD score ≥20. Standardized ammonia levels (ammonia level/upper limit of normal of each center) correlated significantly, albeit weakly with PHES (Spearman ρ = -0.16, P < 0.001).

DISCUSSION

The prevalence of MHE in patients with cirrhosis was high but varied substantially between diseases stages. These data may pave the way for more individualized MHE screening approaches.

Influence of NOD2 risk variants on hepatic encephalopathy and association with inflammation, bacterial translocation and immune activation

BACKGROUND

Nucleotide-binding oligomerization domain containing 2 (NOD2) risk variants lead to impaired mucosal barrier function, increased bacterial translocation (BT), and systemic inflammation.

AIM

To evaluate the association between the presence of NOD2 risk variants, BT, inflammation, and hepatic encephalopathy (HE).

PATIENTS AND METHODS

This prospective multicenter study included patients with cirrhosis and testing for NOD2 risk variants (p.R702W, p.G908R, c.3020insC, N289S, and c.-958T>C). Patients were evaluated for covert (C) and overt (O) HE. Markers of systemic inflammation (leukocytes, CRP, IL-6, LBP) and immune activation (soluble CD14) as well as bacterial endotoxin (hTRL4 activation) were determined in serum.

RESULTS

Overall, 172 patients (70% men; median age 60 [IQR 54-66] years; MELD 12 [IQR 9-16]; 72% ascites) were included, of whom 53 (31%) carried a NOD2 risk variant. In this cohort, 11% presented with OHE and 27% and CHE. Presence and severity of HE and surrogates of inflammation, BT, and immune activation did not differ between patients with and without a NOD2 risk variant, also not after adjustment for MELD. HE was associated with increased ammonia and systemic inflammation, as indicated by elevated CRP (w/o HE: 7.2 [2.7-16.7]; with HE 12.6 [4.5-29.7] mg/dL; p < 0.001) and elevated soluble CD14 (w/o HE 2592 [2275-3033]; with HE 2755 [2410-3456] ng/mL; p = 0.025).

CONCLUSIONS

The presence of NOD2 risk variants in patients with cirrhosis is not associated with HE and has no marked impact on inflammation, BT, or immune activation. In contrast, the presence of HE was linked to ammonia, the acute phase response, and myeloid cell activation.

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?

Rest-activity rhythm disturbance in liver cirrhosis and association with cognitive impairment

Cognitive impairment and disturbed sleep-wake rhythms are disabling complications of liver cirrhosis, yet there is limited understanding of how they are related. We tested the hypothesis that alterations of sleep, rest-activity, and light exposure patterns are associated with worse cognition in cirrhosis. A total of 54 ambulatory adult patients with cirrhosis and 41 age-/gender-matched healthy controls wore wrist actigraphy for rest-activity and light measurements and completed Patient-Reported Outcomes Measurement Information System sleep instruments for self-reported sleep quality. We used standard nonparametric descriptors to characterize rest-activity and light patterns, and wake after sleep onset and sleep efficiency to assess objective sleep quality. The NIH Toolbox cognition battery was used for objective cognitive evaluation using T-scores from a demographically adjusted population reference. Spearman's correlation and multivariable models were used to explore associations between measures of cognition, sleep, rest-activity, and light. Cognition was significantly impaired in cirrhosis patients. Sleep quality was worse in cirrhosis patients by subjective and objective measures compared with controls. Cirrhosis patients exhibited fragmented and dampened rest-activity rhythms, lower daytime and higher nighttime light exposure compared with controls. Worse working memory and processing speed was associated with lower daytime activity level, higher rest-activity fragmentation, lower day-to-day stability, and greater nocturnal light exposure. No association was found between cognition and sleep quality. Rest-activity fragmentation and abnormal light exposure patterns are common in patients with liver disease and are associated with the severity of cognitive impairment. Further research is needed to investigate the effects of timed bright light and exercise intervention on cognitive function in patients with liver disease.

Proposal of Stroop test cut-off values as screening for neuropsychological impairments in cirrhosis: A Japanese multicenter study

AIM

Despite its relevant clinical impact and high prevalence, covert hepatic encephalopathy (HE) still remains underdiagnosed. As patients with liver cirrhosis tend to be older in Japan, more suitable tests for the elderly and cut-off values based on this attribute are needed. Recently, a Stroop test has been developed and validated for the screening and diagnosis of covert HE in the United States. The present study aims to establish the cut-off values of the Stroop test to screen covert HE.

METHODS

This study was a prospective multicenter cross-sectional endeavor. We undertook a survey of 311 cirrhotic patients, administering the number connection test (NCT)-A and -B and the Stroop-off and -on test.

RESULTS

We determined the cut-off values of Stroop test results for cirrhotic patients in a variety of age ranges. The cut-off value of the Stroop test was strongly correlated with age. There was a significant correlation between the results of NCT-B and age, and Stroop-on test results showed a correlation with serum albumin (Alb) levels. Serum Alb ≤3.2 g/dl could have the potential to be an objective biomarker of covert HE. In addition, stepwise logistic regression analysis revealed a relationship between the results of the Stroop-on test and plasma ammonia levels.

CONCLUSIONS

We established the cut-off values of Stroop test results and confirmed the efficacy of the Stroop test as a simple tool for assessing cognitive alterations. The Stroop test could be suitable as a necessary minimum for the diagnosis of covert HE.

Covert hepatic encephalopathy and spontaneous portosystemic shunts increase the risk of developing overt hepatic encephalopathy

AIM

The aim of the study was to evaluate the presence of covert hepatic encephalopathy (cHE) and its characteristics according to the presence of spontaneous portosystemic shunts (SPSS) and their influence on the development of overt hepatic encephalopathy.

METHODS

Secondary analysis of a multicentre study, which evaluated the association between SPSS and complications of cirrhosis. The present study population includes those patients who also underwent cHE diagnostic evaluation. Presence of SPSS was evaluated by cross-sectional imaging and quantified by total SPSS-area. Logistic and Cox-regression competing risk analyses were performed.

RESULTS

About 65 patients were included of age 58 (IQR 50-66), MELD 15 (IQR 10-20), with alcoholic liver disease 63%. Thirty-two patients (49%) had cHE, had higher MELD [16 (IQR 12-24) vs 13 (IQR 9-17), P = .027], a greater proportion of SPSS [n = 18 (56%) vs n = 8 (24%); P = .008] and a higher total cross-sectional SPSS-area [28.3 (0-94.2) vs 0 (0-14.1); P = .005]. On multivariate analysis MELD [OR 1.11 (95% CI 1.01-1.21)] and presence of SPSS [OR 3.95 (95% CI 1.22-12.80)] were independently associated to cHE at baseline. During follow-up cHE was an independent predictor of oHE [cHE: HR 6.93 (95% CI 2.64-18.20). The effect of cHE on the development of oHE was greater in patients with SPSS [only cHE: HR 5.66 (95% CI 1.82-17.62), cHE and SPSS: HR 8.63 (95% CI 3.15-23.65)].

CONCLUSIONS

cHE is independently associated to the presence of SPSS (and total cross-sectional SPSS-area) and MELD. Furthermore, the presence of SPSS seems to increase the risk of cHE of developing of overt hepatic encephalopathy.

Cognition-tracking-based strategies for diagnosis and treatment of minimal hepatic encephalopathy

Minimal hepatic encephalopathy (MHE), which shows mild cognitive impairment, is a subtle complication of cirrhosis that has been shown to affect daily functioning and quality of life. However, until 2014, relevant guidelines do not give much attention to the diagnosis and treatment of MHE, resulting in patients being ignored and denied the benefits of treatment. In this review, we summarize recent cognition-based research about (1) alteration of nerve cells, including astrocytes, microglial cells and neurons, in mild cognitive impairment in MHE; (2) comparison of methods in detecting cognitive impairment in MHE; and (3) comparison of methods for therapy of cognitive impairment in MHE. We hope to provide information about diagnosis and treatment of cognitive impairment in patients with MHE.

Lauridsen M. Prediction of overt hepatic encephalopathy by the continuous reaction time method and the portosystemic encephalopathy syndrome test in clinically mentally unimpaired patients with cirrhosis

Background and aim

Predicting overt hepatic encephalopathy (OHE) is important because the condition is frequent, often requires hospitalization and is potentially preventable. The risk of OHE is related to pre-existing discrete cognitive defects, and for clinical practice it is recommended to apply two different psychometric tests to detect such deficits. We used the continuous reaction time test (CRT) and the portosystemic encephalopathy (PSE) syndrome test and examined their single and combined value for OHE prediction in cirrhosis patients.

Patients and methods

We studied 130 clinically mentally unimpaired cirrhosis patients by the two tests and followed them for an average of 38.5 months. The CRT measures velocity and stability of motor reaction times to 150 repeated auditory signals. The PSE is a five sub-set paper-and-pencil test battery evaluating cognitive and psychomotor processing, speed and vision-motor coordination. We collected data on episodes of OHE during follow-up. The clinical course was analysed in patient groups according to the outcome of each test and of both tests together. No anti-HE treatment was initiated except for cases with OHE.

Results

At baseline, the CRT test was abnormal in 74 patients and the PSE in 47. During follow-up 35 patients (27%) experienced 74 OHE events. 23 patients with abnormal CRT experienced OHE (prediction sensitivity 65%). The PSE predicted OHE in 14 patients (prediction sensitivity 40%). One or both tests were abnormal in 87/130 (67%) and this predicted OHE in 27 patients (21%) (prediction sensitivity 77%).

Conclusion

The CRT test was clinically useful in identifying two-thirds of clinically mentally unimpaired cirrhosis patients who later experienced OHE, and the use of both the CRT and PSE showed satisfactory prediction by identifying three-fourths of later OHE cases.

Critical flickering frequency test: a diagnostic tool for minimal hepatic encephalopathy

BACKGROUND

Minimal hepatic encephalopathy (MHE) is underestimated. It affects 30-55% of patients with liver cirrhosis and can change their daily functions. Psychometric tests are sensitive in diagnosing MHE, but interpretation is difficult. Availability of a simpler diagnostic tool for MHE is mandatory. Critical flicker frequency (CFF) is a simple diagnostic test.

AIM

The aim of this study was to assess the diagnostic accuracy of CFF test for MHE.

PATIENTS AND METHODS

A total of 86 patients with cirrhosis with negative history of overt hepatic encephalopathy were included. History, clinical examination, laboratory investigations, and abdominal ultrasonography data were collected. Arabic version of number connection test, serial dotting test, and line tracing test were done. Total psychometric hepatic encephalopathy score (PHES) was used to diagnose MHE. CFF was done for all patients with MHE diagnosis at 39 Hz.

RESULTS

Of the 86 patients, 45 (52.3%) had MHE with PHES. Patients with MHE had significantly older age, presentation with jaundice, ascites, lower hemoglobin level, lower serum albumin, prolonged INR, higher Child class and score (P≤0.001), and higher model of end stage liver disease score (P=0.001) than patients without MHE. In comparison with PHES, CFF has a sensitivity of 91.1±8.32%, specificity of 92.7±7.96%, positive predictive value of 93.2±7.44%, and negative predictive value of 90.4±8.91%. In receiver operating characteristic curve, CFF is excellent in diagnosis of MHE, with area under the curve 0.937 (P<0.001).

CONCLUSION

MHE is common among patients with liver cirrhosis. CFF is a simple, rapid, noninvasive test for diagnosis of MHE, with a very good accuracy at 39 Hz.

Predicting Overt Hepatic Encephalopathy for the Population With Cirrhosis

Hepatic encephalopathy (HE) is associated with poor quality of life, sharply increased mortality, repeated hospitalizations, falls, and motor vehicle accidents. HE manifests with a dynamic spectrum of severity. Overt HE is clinically obvious disorientation, even coma. Although multiple strategies are available to characterize early-stage HE, data are limited that validate these methods in predicting overt HE, many are impractical in clinical practice, and test cutoffs relevant to the average patient clinicians manage are lacking. To accurately and efficiently classify the risk of overt HE in the population with cirrhosis, novel strategies may be needed. Herein, we review the potential competing strategies for the prediction of overt HE. Conclusion: We propose refining diagnostic cutoffs for tests that are designed to define early HE, using overt HE as a gold standard and expanding prediction tools by using measures of components from the risk pathway for HE.

Covert hepatic encephalopathy leads to distinct alterations in the emotional state, independently of MELD-Score

BACKGROUND AND AIMS

Covert hepatic encephalopathy impairs many aspects of quality of life, although its impact on the emotional state has not been evaluated. This study aims to evaluate the impact of covert hepatic encephalopathy on the emotional state and which factors are associated with changes in the emotional state in patients with cirrhosis.

METHODS

This single-center study included all patients with cirrhosis who underwent the portosystemic encephalopathy syndrome (PSE) test, critical flicker frequency, and emotional state assessment with the Eigenschaftswörterliste 60-S in 2011. Covert hepatic encephalopathy was defined by abnormal PSE. Parametric and non-parametric tests were used according to variable distribution.

RESULTS

One hundred seventeen patients with cirrhosis were included (median age: 59 [interquartile range: 48 - 67], 32 % female, 74 % alcohol-associated). Seventy patients had covert hepatic encephalopathy (60 %) with a higher MELD (16 [interquartile range: 13 - 21], p = 0.001) and a higher Child-Pugh score (p = 0.003) compared to patients without encephalopathy. Patients with covert encephalopathy felt reduced mental activity (p = 0.004), lower general well-being (p = 0.001), and reduced extraversion (p = 0.021). The scores in the negative domains such as general lethargy (p = 0.031) and anxiousness/depressiveness (p = 0.033) were higher in patients with covert hepatic encephalopathy. There was no correlation between MELD and the emotional state. Patients with 2 pathological tests (critical flicker frequency and PSE) showed the most distinct alterations in the emotional state in the group of patients with covert hepatic encephalopathy.

CONCLUSIONS

Patients with covert hepatic encephalopathy have an alteration of the emotional state, which is more marked in patients with 2 pathological tests. Interestingly, MELD had no impact on the emotional state.

Recent advances in hepatic encephalopathy

Hepatic encephalopathy describes the array of neurological alterations that occur during acute liver failure or chronic liver injury. While key players in the pathogenesis of hepatic encephalopathy, such as increases in brain ammonia, alterations in neurosteroid levels, and neuroinflammation, have been identified, there is still a paucity in our knowledge of the precise pathogenic mechanism. This review gives a brief overview of our understanding of the pathogenesis of hepatic encephalopathy and then summarizes the significant recent advances made in clinical and basic research contributing to our understanding, diagnosis, and possible treatment of hepatic encephalopathy. A literature search using the PubMed database was conducted in May 2017 using "hepatic encephalopathy" as a keyword, and selected manuscripts were limited to those research articles published since May 2014. While the authors acknowledge that many significant advances have been made in the understanding of hepatic encephalopathy prior to May 2014, we have limited the scope of this review to the previous three years only.