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

Smartphone-based Stroop Test, EncephalApp: What is the optimal cutoff for diagnosing minimal hepatic encephalopathy?

Jiang et al explored the diagnostic capabilities of EncephalApp, a smartphone-based Stroop Test, in patients with nonalcoholic liver disease. The study included 160 patients with nonalcoholic cirrhosis and utilized the psychometric hepatic encephalopathy score as a benchmark for diagnosing minimal encephalopathy. The identified optimal cutoff times were > 101.93 seconds for the "off" time and > 205.86 seconds for the combined "on + off" time, demonstrating sensitivities of 0.84 and 0.90, and specificities of 0.77 and 0.71, respectively. The findings suggest the necessity of employing different cutoffs for patients with alcoholic vs nonalcoholic liver cirrhosis, reflecting the distinct pathophysiologies underlying each condition. Additionally, alcohol consumption itself may influence Stroop test outcomes. Therefore, it is reasonable to establish separate benchmarks for alcoholic and nonalcoholic cirrhotic patients. Further validation in larger patient cohorts with clinical outcomes is essential. The demand for noninvasive liver disease assessments remains high in clinical practice.

QuickStroop for screening for minimal hepatic encephalopathy in patients with cirrhosis

Background & Aims

QuickStroop, a shortened version of the Stroop EncephalApp, has recently been proposed for screening for minimal hepatic encephalopathy (MHE) in patients with cirrhosis in the USA. At present, there are no data on its clinical utility for MHE screening in patients in Europe, and only limited data are available regarding its comparison to the Animal Naming Test (ANT).

Methods

In total, 242 patients with cirrhosis without signs of hepatic encephalopathy (HE) ≥ grade 1 and no history of overt HE were included as the development cohort. Another independent cohort comprising 104 patients with cirrhosis from a different center served as a validation set. MHE was defined using the psychometric hepatic encephalopathy score (PHES) (PHES-MHE). All patients were tested with the complete EncephalApp Stroop. A subset was also tested with the ANT. Regression formulas were fitted for patients above and below the age of 60 years, including the first two off-state runs, age, and school education (QuickStroop).

Results

PHES-MHE was detected in 76 (31%) patients. The first two off-state runs of the EncephalApp demonstrated a comparable discriminative ability to the complete Stroop test in distinguishing between patients with and without PHES-MHE. QuickStroop had a better discriminative ability in patients below than above the age of 60 years. The discriminative ability of QuickStroop (total cohort: AUC 0.88) was superior to ANT (AUC 0.70). QuickStroop predicted PHES-MHE with a sensitivity of 74% and a specificity of 89%, and took a median of only 34.5 s to complete. The acceptable discriminative ability of QuickStroop was confirmed in the validation cohort (AUC 0.81).

Conclusion

QuickStroop is a rapid screening tool to identify patients at risk for PHES-MHE, especially in patients below 60 years of age.

Impact and implications

QuickStroop, a shortened version of the Stroop EncephalApp, has recently been proposed for screening for MHE in patients with cirrhosis in the USA. In this study, we validated QuickStroop for patients in Germany with cirrhosis and demonstrate a good diagnostic accuracy for detecting MHE, especially in patients below 60 years of age. Additionally, QuickStroop might be superior to the ANT in patients below 60 years of age. The use of QuickStroop in clinical practice could facilitate screening for MHE.

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.

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.

Minimal hepatic encephalopathy is associated with a higher risk of overt hepatic encephalopathy and poorer survival

BACKGROUND AND AIMS

Minimal hepatic encephalopathy (MHE) is a frequent complication in patients with liver cirrhosis. Its impact on predicting the development of overt hepatic encephalopathy (OHE) and survival has not been studied in large multicenter studies.

METHODS

Data from patients recruited at eight centers across Europe and the United States were analyzed. MHE was detected using the psychometric hepatic encephalopathy score (PHES). A subset was also tested with the simplified animal naming test (S-ANT1). Patients were followed for OHE development and death/liver transplantation (LTx).

RESULTS

A total of 1462 patients with a median model of end-stage liver disease of 11 were included (Child-Pugh (CP) stages: A 47%/B 41%/C 12%). Median follow-up time was 19 months, during which 336 (23%) patients developed an OHE episode and 464 (32%) reached the composite end point of death/LTx (369 deaths, 95 LTx). In multivariable analyses, MHE (defined by PHES) was associated with the development of OHE (subdistribution hazard ratio 1.74, p < 0.001) and poorer LTx-free survival (hazard ratio 1.53, p < 0.001) in the total cohort as well as in the subgroup of patients without a history of OHE. In subgroup analyses, MHE (defined by PHES) was associated with OHE development in patients with CP B, whereas there was no association in patients with CP A or C. In the subgroup of patients with available S-ANT1, MHE (defined by S-ANT1) was independently associated with OHE development. Combined testing (PHES+S-ANT1) was superior to single testing for predicting OHE and poorer LTx-free survival.

CONCLUSIONS

This large multicenter study demonstrates that screening for MHE is a useful tool for predicting OHE and poorer survival.

Prediction and prevention of the first episode of overt hepatic encephalopathy in patients with cirrhosis

Hepatic encephalopathy (HE) is one of the most important complications of patients with liver cirrhosis. In addition, HE is associated with a dismal prognosis and has detrimental effects on patients' quality of life. Thus, it is of pivotal importance to identify patients at high risk for overt HE (OHE) in whom primary prophylaxis may be justified. In this narrative review, we aim to provide insight into predictors and prediction tools for a first-time episode of OHE and to scrutinize the current level of evidence of primary prophylaxis. In recent decades, several cognitive tests, composite scores, and blood-based biomarkers have been demonstrated to be predictive of a first-time episode of OHE. Among the best validated are the established tests for minimal HE, such as the Psychometric Hepatic Encephalopathy Score, determination of the critical flicker frequency, Stroop EncephalApp, or the Animal Naming Test. Individualized risk stratification using blood-based biomarkers and cross-sectional imaging (sarcopenia and spontaneous portosystemic shunts) is coming to the fore, but validation in larger multicenter cohorts is often lacking. On the basis of current evidence, a recommendation for primary prophylaxis of a first episode of OHE cannot be made in general. Only 2 studies have investigated the prevention of a first-time OHE episode as the primary endpoint. In this narrative review, we provide a concise overview of the current evidence levels on prediction tools and pharmacological prevention of a first episode of OHE. In addition, we give an outlook on future research targets to improve knowledge on this important topic.

Current vision on diagnosis and comprehensive care in hepatic encephalopathy

The first clinical guidelines on hepatic encephalopathy were published in 2009. Almost 14 years since that first publication, numerous advances in the field of diagnosis, treatment, and special condition care have been made. Therefore, as an initiative of the Asociación Mexicana de Gastroenterología A.C., we present a current view of those aspects. The manuscript described herein was formulated by 24 experts that participated in six working groups, analyzing, discussing, and summarizing the following topics: Definition of hepatic encephalopathy; recommended classifications; epidemiologic panorama, worldwide and in Mexico; diagnostic tools; conditions that merit a differential diagnosis; treatment; and primary and secondary prophylaxis. Likewise, these guidelines emphasize the management of certain special conditions, such as hepatic encephalopathy in acute liver failure and acute-on-chronic liver failure, as well as specific care in patients with hepatic encephalopathy, such as the use of medications and types of sedation, describing those that are permitted or recommended, and those that are not.

A shortened Stroop test to identify covert hepatic encephalopathy and predict overt hepatic encephalopathy in patients with cirrhosis

BACKGROUND

Covert hepatic encephalopathy (CHE) adversely affects the clinical outcomes of patients with cirrhosis but remains largely undiagnosed and untreated. Although the Stroop test is a useful method for CHE detection, a faster, simpler, and more accurate test is required to diagnose CHE. This prospective study aimed to develop a new shortened Stroop test that can detect CHE and predict overt hepatic encephalopathy (OHE) in Japanese patients with cirrhosis.

METHODS

Patients who underwent neuropsychological tests (NPT) and the Stroop test between November 2018 and December 2021 were enrolled and followed until OHE occurrence or March 2022. The discriminative ability of various run combinations in the off and on states to detect CHE was evaluated using the area under the receiver-operating characteristic curve (AUC) and compared with that of the total Stroop test time.

RESULTS

Among the 227 eligible patients, the On1-2Time cutoff value of 44.4 s had a comparable discriminative ability with the total Stroop test time to detect CHE, with an AUC of 0.791, a sensitivity of 0.827, and a specificity of 0.685. During a median follow-up period of 16 months, 37 patients developed OHE. On1-2Time ≥ 44.4 s (hazard ratio [HR], 3.93; 95% confidence interval [CI] 1.36-11.36) and serum albumin levels (HR, 0.28; 95% CI 0.11-0.67) were independently associated with OHE occurrence.

CONCLUSIONS

The shortened Stroop test (On1-2Time) is equivalent to the total Stroop test not only for identifying CHE but also for estimating the risk of progression to OHE.