Normalization of the psychometric hepatic encephalopathy score in Polish population. A prospective, quantified electroencephalography study

Detection of minimal hepatic encephalopathy in patients with cirrhosis based on the Stroop-CN model (NCRCID-CHESS 2106): a prospective multicenter study

Minimal hepatic encephalopathy (MHE) has a substantial impact on the clinical outcomes and quality of life (QOL) of patients with cirrhosis. However, timely diagnosis and intervention are challenging due to sophisticated diagnostic methods. In this study, 673 healthy controls and 905 patients with cirrhosis were screened, and 660 healthy controls and 757 patients with cirrhosis, divided into the test (292 patients) and validation (465 patients) cohort, were analyzed after screening. A diagnostic model of the Stroop test (Stroop-CN) was constructed by multivariate linear regression based on the results of healthy controls. The prevalence of MHE and the comparison results with psychometric hepatic encephalopathy score through the Stroop-CN model were stable in the test and validation cohorts. Moreover, the prevalence of MHE remained significantly higher in patients with worse disease conditions marked as high Child-Pugh grades and the Model for End-stage Liver Disease and Sodium (MELD-Na) scores in the test and validation cohort. The EuroQol 5-D questionnaire revealed that patients with MHE had a worse QOL than those without MHE both in the test and validation cohort. In conclusion, an easy and practical Stroop-CN model for MHE diagnosis based on the EncephalApp is established. It is found that a considerable number of Chinese patients with cirrhosis experience MHE, which significantly impacts their QOL.

Portosystemic Hepatic Encephalopathy Scores (PHES) differ between Danish and German healthy populations despite their geographical and cultural similarities

Minimal hepatic encephalopathy (MHE) is common in liver cirrhosis and is identified by psychometric tests. The portosystemic hepatic encephalopathy score (PHES) is the most widely used and serves as an inter-study comparator. PHES has not been standardised for use in the Danish population, where German normal values have been applied until now based on the notion that the populations are comparable. This study aimed to evaluate if German PHES normal values can be applied in the Danish population and establish Danish normal values if needed. 200 Danish and 217 German healthy persons underwent Number Connection Test A and B (NCT), Line Tracing Test (LTT), Digit Symbol Test (DST), and Serial Dotting Test (SDT), and based on performance, PHES was calculated. German and Danish PHES performance declined with age in all subtests but more rapidly in Danes. Both German and Danish norms were impacted by gender and education, but to a different extent in the single tests of the test battery. Accordingly, there was a need for specific Danish normal values, which are presented here. Applying the new Danish normal values instead of the German in patients with cirrhosis yielded a lower percentage of out-of-norm performances (58% vs. 66%) and, hence, a lower prevalence of MHE. Danes and Germans perform differently on PHES, and therefore, normal German values cannot be used in Danish patients. Danish normal values are presented here and yield a lower number of 'out of norm' performances.

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

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

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?

Minimal hepatic encephalopathy - diagnosis and treatment

Hepatic encephalopathy is a dysfunction of the central nervous system caused by chronic and acute liver disease. It presents a wide spectrum of symptoms from undetectable in a standard clinical examination to hepatic coma. The mildest form of hepatic encephalopathy is minimal hepatic encephalopathy. It significantly influences the quality of life, prognosis, and the incidence of complications. A wide range of psychometric and neurophysiological tests are used in the diagnostics. Treatment is based on the same principles as in overt encephalopathy. The most commonly used drugs include rifaximin, ornithine aspartate, and LOLA.

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.

Artificial Intelligence and Its Application to Minimal Hepatic Encephalopathy Diagnosis

Hepatic encephalopathy (HE) is a brain dysfunction caused by liver insufficiency and/or portosystemic shunting. HE manifests as a spectrum of neurological or psychiatric abnormalities. Diagnosis of overt HE (OHE) is based on the typical clinical manifestation, but covert HE (CHE) has only very subtle clinical signs and minimal HE (MHE) is detected only by specialized time-consuming psychometric tests, for which there is still no universally accepted gold standard. Significant progress has been made in artificial intelligence and its application to medicine. In this review, we introduce how artificial intelligence has been used to diagnose minimal hepatic encephalopathy thus far, and we discuss its further potential in analyzing speech and handwriting data, which are probably the most accessible data for evaluating the cognitive state of the patient.

Standardization of the psychometric hepatic encephalopathy score in a French population

The Psychometric Hepatic Encephalopathy Score (PHES) has previously been standardized in thirteen countries on three continents, confirming its status of gold standard test to detect minimal hepatic encephalopathy (MHE). In the meantime, performance has also been shown to vary with variables such as age, education, and barely sex. The present study aimed at standardizing the PHES in a French population. One hundred and ninety-six French healthy participants completed a French version of the paper-and-pencil PHES, involving five tests and six measures. Importantly, the balance was perfect between all levels of the three controlled factors, which were sex, age (seven decade-levels from 20–29 to 80–89 years), and education (two levels below or above 12 years of education). Raw measures were transformed to fit the normal distribution. ANOVAs on transformed variables showed no effect of sex, but an effect of age on all measures, and of education on five measures. Multiple or simple regressions were completed to build up normograms. Thorough analysis of variability within each test failed to find outliers that may bias the results. Comparison between French and seminal German data showed that they highly fitted though cultural and cognitive style specificities could be observed. This is the first study to standardize the PHES in a French population and to extensively explore the effects of sex, age and education using perfectly balanced samples. Subtle differences between countries of the same continent emphasize the need to build up normative data in each country to get accurate PHES in patients.

Brain-derived neurotrophic factor as a potential diagnostic marker in minimal hepatic encephalopathy

Introduction

Minimal hepatic encephalopathy (MHE) is a common complication of liver cirrhosis not only leading to a decrease in the quality of life, but also predicting development of overt encephalopathy. The diagnosis of MHE usually relies on a combination of neuropsychological tests, while robust serum biomarkers are lacking. We aimed to assess serum concentrations of brain-derived neurotrophic factor (BDNF) in MHE patients.

Material and methods

Serum BDNF was assessed in 78 patients with liver cirrhosis (53 male, median age 55 years) and 40 healthy individuals. 43 subjects underwent extensive evaluation for MHE by psychometric hepatic encephalopathy score (PHES) and inhibitory control test (ICT) or critical flicker frequency (CFF).

Results

Serum BDNF was twofold lower in liver cirrhosis compared to healthy subjects [13.6 (7.8-22.6) vs. 33.0 (24.1-40.7) ng/ml, p < 0.001] and its decrease reflected a degree of liver insufficiency assessed by model for end-stage liver disease (MELD). BDNF showed a negative correlation with bilirubin (R = –0.35, p = 0.005) and international normalized ratio (INR) (R = –0.37, p = 0.003), and positive with platelets (PLT) (R = 0.36, p = 0.004), while no associations with age, sex, body mass index (BMI), waist-hip ratio (WHR), creatinine and ammonia were noted. Importantly, subjects with a diagnosis of MHE by at least two modalities showed the lowest levels of BDNF [10.9 (2.5-14.4) vs. 19.9 (9.3-29.4) ng/ml, p < 0.01]. Patients with self-reported sleep disturbances had significantly lower serum BDNF [13.0 (2.5-23.4) vs. 20.0 (8.4-31.3) ng/ml, p = 0.04].

Conclusions

The lowest serum BDNF concentration was noted in patients with MHE and sleep disturbances, which suggests a role in pathophysiology of hepatic encephalopathy but also as a potential biomarker.

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.

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.

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).

Diagnosis of minimal hepatic encephalopathy in a tertiary care center from eastern Romania: validation of the psychometric hepatic encephalopathy score (PHES)

The psychometric hepatic encephalopathy score (PHES) is frequently used as a "gold standard" for the diagnosis of minimal hepatic encephalopathy (MHE). In Romania, there are currently no widely available tests for the detection of MHE. In this study we aimed to standardize the PHES in a healthy Romanian population and to estimate the prevalence of MHE in a group of Romanian patients with liver cirrhosis. A total of 260 healthy volunteers and 106 patients with liver cirrhosis were included in the study. The five neuropsychological tests comprising the PHES were administered to all enroled subjects. Blood samples for routine tests and serum ammonia were collected. In the healthy volunteer group age and education years were found to be predictors of all tests and gender only in two tests: digit symbol test and serial dotting test. The PHES of the healthy volunteer group was 0,43 ± 1,37 and the cut-off between normal and pathological values was set at -3 points. In the liver cirrhosis group the mean PHES was -2,44 ± 3,41, significantly lower than in the control group (p = 0,001). The estimated prevalence of MHE was 34,7 % (37 patients). In patients with cirrhosis there was a significant correlation between PHES and the severity of the liver disease according to Child-Pugh classification (r = 0,529, p = 0,001) and MELD score (r = -0,525, p = 0,001). According to our results, accurate Romanian PHES norms for the diagnosis of MHE have been developed. MHE was diagnosed in a significant proportion of Romanian patients with liver cirrhosis.

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.

Minimal hepatic encephalopathy: A review

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

Diagnosis and Treatment of Low-Grade Hepatic Encephalopathy

Minimal hepatic encephalopathy (mHE) is common among patients with cirrhotic liver disease and causes significant morbidity and mortality. It may present as cognitive impairment, behavioural changes and, less frequently, with neurological symptoms which make diagnosis of the disease challenging. A history of falls and accidents may also be suggestive of mHE. Diagnosis primarily relies on at least two positive psychometric tests of which the psychometric hepatic encephalopathy score (PHES) is essential. Alternatively, PHES and an electroencephalogram may be used to establish a diagnosis. Biochemical markers of encephalopathy currently have no role in the diagnosis of mHE. Treatment is not always advocated for a diagnosis of mHE but is dependent on the degree of impairment caused by the symptoms. After treatment of other metabolic abnormalities and co-morbidities associated with cirrhosis, more specific treatment for mHE largely relies on therapies used to lower ammonia levels. Laxatives and rifaximin are commonly used in treatment and work through decreasing ammonia absorption from the gut. Other therapies, such as BCAA, LOLA, L-carnitine and phenylbutyrate, modify responses to ammonia as well as enhancing metabolism and excretion. mHE resulting from spontaneous portosystemic shunts or transhepatic intraportal systemic shunts may require ablation or reduction of the shunt. Early detection and appropriate treatment of mHE is important to prevent significant cognitive impairments and progression to overt HE.

Diagnosis of minimal hepatic encephalopathy

Minimal hepatic encephalopathy (mHE) has significant impact upon a liver patient's daily living and health related quality of life. Therefore a majority of clinicians agree that mHE should be diagnosed and treated. The optimal means for diagnosing mHE, however, is controversial. This paper describes the currently most frequently used methods-EEG, critical flicker frequency, Continuous Reaction time Test, Inhibitory Control Test, computerized test batteries such as the Cognitive Drug Research test battery, the psychometric hepatic encephalopathy score (PHES) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS)-and their pros and cons.

Hepatic encephalopathy in patients with acute decompensation of cirrhosis and acute-on-chronic liver failure

Hepatic encephalopathy in a hospitalized cirrhotic patient is associated with a high mortality rate and its presence adds further to the mortality of patients with acute-on-chronic liver failure (ACLF). The exact pathophysiological mechanisms of HE in this group of patients are unclear but hyperammonemia, systemic inflammation (including sepsis, bacterial translocation, and insulin resistance) and oxidative stress, modulated by glutaminase gene alteration, remain as key factors. Moreover, alcohol misuse, hyponatremia, renal insufficiency, and microbiota are actively explored. HE diagnosis requires exclusion of other causes of neurological, metabolic and psychiatric dysfunction. Hospitalization in the ICU should be considered in every patient with overt HE, but particularly if this is associated with ACLF. Precipitating factors should be identified and treated as required. Evidence-based specific management options are limited to bowel cleansing and non-absorbable antibiotics. Ammonia lowering drugs, such as glycerol phenylbutyrate and ornithine phenylacetate show promise but are still in clinical trials. Albumin dialysis may be useful in refractory cases. Antibiotics, prebiotics, and treatment of diabetes reduce systemic inflammation. Where possible and not contraindicated, large portal-systemic shunts may be embolized but liver transplantation is the most definitive step in the management of HE in this setting. HE in patients with ACLF appears to be clinically and pathophysiologically distinct from that of acute decompensation and requires further studies and characterization.