Validation of the Korean Stroop Test in Diagnosis of Minimal Hepatic Encephalopathy

Effect of L-carnitine on quality of life in covert hepatic encephalopathy: a randomized, double-blind, placebo-controlled study

BACKGROUND/AIMS

L-carnitine is potentially beneficial in patients with hepatic encephalopathy (HE). We aimed to evaluate the impact of L-carnitine on the quality of life and liver function in patients with liver cirrhosis and covert HE.

METHODS

We conducted an investigator-initiated, prospective, multi-center, double- blind, randomized phase III trial in patients with covert HE. A total of 150 patients were randomized 1:1 to L-carnitine (2 g/day) or placebo for 24 weeks. Changes in quality of life and liver function were assessed at 6 months. The model for end-stage liver disease (MELD), the 36-Item Short Form Survey (SF-36), the psychometric hepatic encephalopathy score (PHES), and the Stroop Test were evaluated in all patients.

RESULTS

The total SF-36 score significantly improved in the L-carnitine group after 24 weeks (difference: median, 2; interquartile range, 0 to 11; p < 0.001); however, these values were comparable between the two groups. Furthermore, there was a significant ordinal improvement in PHES scores among patients with minimal HE who were in the L-carnitine group (p = 0.007). Changes in the total carnitine level also positively correlated with improvements in the Stroop test in the L-carnitine group (color test, r = 0.3; word test, r = 0.4; inhibition test, r = 0.5; inhibition/switching test, r = 0.3; all p < 0.05). Nevertheless, the MELD scores at week 24 did not differ between the groups.

CONCLUSION

Twenty-four weeks of L-carnitine supplementation was safe but ineffective in improving quality of life and liver function.

EncephalApp Stroop Test validation for the screening of minimal hepatic encephalopathy in Brazil

INTRODUCTION AND OBJECTIVES

The EncephalApp Stroop Test was developed to more easily diagnose minimal hepatic encephalopathy (MHE). A cut-off of >274.9sec (ONtime+OFFtime) reached a 78% sensitivity and 90% specificity in the validation study, but it has been poorly studied in Brazil. We aim to analyze the usefulness of this diagnostic method and to describe a cut-off value to screen MHE in Brazil.

METHODS

In this cross-sectional and single-center study, three positive psychometric tests defined the diagnosis of MHE as the gold standard. We evaluated gender, age, education, familiarity with smartphones, etiology of cirrhosis, Child-Pugh/MELD scores, and previous hepatic encephalopathy (HE). Healthy controls and patients without HE were compared for the task validation. The Chi-square and Mann-Whitney tests, logistic regression analysis, and ROC curves were used for statistical evaluation.

RESULTS

We included 132 patients with cirrhosis (61% male) and 42 controls (62% male) around 51y. Sixty-three were diagnosed with MHE on psychometric tests and 23 had clinical HE. Viral hepatitis (38%) was the major etiology of cirrhosis. The median MELD was 10 and Child-Pugh A was more frequent (70%). There was no significant difference in test results between controls and patients without HE. There was also no influence of gender, age, education, and familiarity with smartphones in the test results. Child-Pugh A was associated with MHE (p=0.0106). A cut-off of >269.8sec (ONtime+OFFtime) had an 87% sensitivity and 77% specificity to detect MHE (p=0.002).

CONCLUSION

This is a valid and reliable tool for screening MHE. However, optimal cut-off values need to be validated locally.

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?

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.

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.

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.