Minimal hepatic encephalopathy characterized by parallel use of the continuous reaction time and portosystemic encephalopathy tests

Identifying Minimal Hepatic Encephalopathy: A New Perspective from Magnetic Resonance Imaging

Type C hepatic encephalopathy (HE) is a condition characterized by brain dysfunction caused by liver insufficiency and/or portal-systemic blood shunting, which manifests as a broad spectrum of neurological or psychiatric abnormalities, ranging from minimal HE (MHE), detectable only by neuropsychological or neurophysiological assessment, to coma. Though MHE is the subclinical phase of HE, it is highly prevalent in cirrhotic patients and strongly associated with poor quality of life, high risk of overt HE, and mortality. It is, therefore, critical to identify MHE at the earliest and timely intervene, thereby minimizing the subsequent complications and costs. However, proper and sensitive diagnosis of MHE is hampered by its unnoticeable symptoms and the absence of standard diagnostic criteria. A variety of neuropsychological or neurophysiological tests have been performed to diagnose MHE. However, these tests are nonspecific and susceptible to multiple factors (eg, aging, education), thereby limiting their application in clinical practice. Thus, developing an objective, effective, and noninvasive method is imperative to help detect MHE. Magnetic resonance imaging (MRI), a noninvasive technique which can produce many objective biomarkers by different imaging sequences (eg, Magnetic resonance spectroscopy, DWI, rs-MRI, and arterial spin labeling), has recently shown the ability to screen MHE from NHE (non-HE) patients accurately. As advanced MRI techniques continue to emerge, more minor changes in the brain could be captured, providing new means for early diagnosis and quantitative assessment of MHE. In addition, the advancement of artificial intelligence in medical imaging also presents the potential to mine more effective diagnostic biomarkers and further improves the predictive efficiency of MHE. Taken together, advanced MRI techniques may provide a new perspective for us to identify MHE in the future. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.

The Assessment of Driving Fitness Using an On-Road Evaluation in Patients With Cirrhosis

INTRODUCTION

The association between cirrhosis and driving performance is of particular clinical relevance because of the life-threatening safety issues both for the driver with cirrhosis and the general public. Study aims were to assess (i) driving competency through the use of an in-office computerized battery and on-road driving assessment (DriveABLE) and (ii) the association between minimal hepatic encephalopathy (MHE), in-office paper-pencil tools, and additional measures (e.g., frailty, depression, cognitive testing) with unsafe driving.

METHODS

Patients were prospectively recruited from 2 tertiary care liver clinics. In-office tests and in-office and on-road assessments of driving competence were completed. The χ 2 test and 1-way analysis of variance were used to analyze differences among those with and without MHE. Logistic regression was used to evaluate predictors of an indeterminate/fail result on the in-office computerized driving assessment battery (DriveABLE Cognitive Assessment Tool [DCAT]).

RESULTS

Eighty patients participated with a mean age of 57 years, 70% male, 75% Child-Pugh B/C, and 36% with a history of overt hepatic encephalopathy. Thirty percent met MHE criteria on both the psychometric hepatic encephalopathy score and the Stroop app tests. Only 2 patients (3%) were categorized as "unfit to drive" in the on-road driving test, one with MHE and the other without. Fifty-eight percent of the patients were scored as indeterminate/fail on the DCAT. This corresponded to a higher mean number of on-road driving errors (5.3 [SD 2.1] vs 4.2 [SD 1.6] in those who passed the DCAT, P = 0.01). Older age (odds ratio 1.3; confidence interval 1.1, 1.5; P = 0.001) and MHE by Stroop/psychometric hepatic encephalopathy score (odds ratio 11.0; confidence interval 2.3, 51.8; P = 0.002) were independently predictive of worse performance on the DCAT.

DISCUSSION

Worse performance in in-office testing was associated with worse scores on a computerized driving assessment battery and more on-road driving errors, but in-office tools were insufficient to predict on-road driving failures. A diagnosis of MHE should not be used alone to restrict driving in patients with cirrhosis. At-risk patients require on-road driving tests under the supervision of driving regulatory agencies. Future studies should continue to refine and evaluate in-office or at-home testing to predict driving performance.

The effect of induced hyperammonaemia on sleep and melanopsin-mediated pupillary light response in patients with liver cirrhosis: A single-blinded randomized crossover trial

Background & aims

Sleep disturbances are related to hepatic encephalopathy and hyperammonaemia in patients with cirrhosis. The circadian rhythm is regulated by light stimulation of the retina via melanopsin-containing ganglion cells. The study aimed to investigate whether induced hyperammonaemia affects the pupillary light response and sleep efficiency in patients with cirrhosis.

Methods

The study was a single-blinded crossover trial including nine patients with cirrhosis. Sleep was evaluated by Pittsburgh Sleep Quality Index (PSQI) and monitored for twelve nights with wrist accelerometers and sleep diaries. On two experimental days, separated by one week, patients were randomized to ingest either an oral amino acid challenge (AAC) or an isocaloric glucose solution (GS). We measured pupillary light response, capillary ammonia, the Karolinska Sleepiness Scale (KSS), and two neuropsychological tests on both experimental days.

Results

The patients had poor self-assessed sleep quality. The amino acid challenge led to a significant increase in capillary ammonia and KSS. The time spent in bed sleeping after AAC was longer and with a reduced movement index compared to baseline but not different from GS. We found no difference in the pupillary light response or neuropsychiatric tests when comparing the effect of AAC with GS.

Conclusions

Patients with cirrhosis had impaired sleep quality. Induced hyperammonaemia led to increased sleepiness but had no acute effect on pupillary light response or the neuropsychiatric tests.

Trial registration

Registration number: NCT04771104.

The Prevalence and Association of Cognitive Impairment with Sleep Disturbances in Patients with Chronic Liver Disease

Introduction/Aim. The aim of this study was to assess the prevalence of cognitive impairments and their association with sleep patterns in a cohort of patients diagnosed with chronic liver disease (CLD). Material and methods. The present paper is a prospective cohort study, carried out over a period of 12 months, among patients with various stages of CLD. We evaluated the cognitive function through psychometric hepatic encephalopathy score (PHES), while sleep was assessed by actigraphy and two self-reported questionnaires: Epworth Sleepiness Scale (ESS) and Pittsburgh Sleep Quality Index (PSQI). Results. Seventy-four patients with CLD were considered eligible and were enrolled between December 2020−November 2021. The prevalence of minimal hepatic encephalopathy (MHE) in the entire cohort was 41.9%, and the diagnosis was considered for PHES scores ≤ −3. Patients with cirrhosis recorded significantly lower PHES scores compared to patients with other CLDs but without cirrhosis (−3.19 ± 3.89 vs. 0.19 ± 2.92, p < 0.05). Patients who exhibited MHE suffered from poor sleep, daytime somnolence, disturbed nighttime sleep, and low overall sleep efficacy. Patients diagnosed with MHE and undergoing treatment with lactulose and/or rifaximin for prevention of overt hepatic encephalopathy (HE) showed better results in terms of sleep parameters compared to patients diagnosed with MHE but without treatment. Conclusions. This research increases awareness regarding the connection between sleep features and MHE in patients with cirrhosis and other CLDs. A deeper insight into the subclinical stages of HE and associated sleep disturbances is warranted in future studies.

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?

A pilot study of golexanolone, a new GABA-A receptor-modulating steroid antagonist, in patients with covert hepatic encephalopathy

BACKGROUND & AIMS

Golexanolone is a novel small molecule GABA-A receptor-modulating steroid antagonist under development for the treatment of cognitive and vigilance disorders caused by allosteric over-activation of GABA-A receptors by neurosteroids. It restored spatial learning and motor coordination in animal models of hepatic encephalopathy (HE) and mitigated the effects of intravenous allopregnanolone in healthy adults in a dose-dependent fashion. Herein, we report data on the safety, pharmacokinetics (PK) and efficacy of golexanolone in adult patients with cirrhosis.

METHODS

Following single/multiple ascending dose studies, adults with Child-Pugh A/B cirrhosis and abnormal continuous reaction time (CRT) on screening were randomized to 3 weeks' dosing with golexanolone (10, 40 or 80 mg BID) or placebo. CRT, psychometric hepatic encephalopathy score (PHES), animal naming test (ANT), Epworth sleepiness scale (ESS) and electroencephalogram (mean dominant frequency [MDF]; delta+theta/alpha+beta ratio [DT/AB]) were obtained at baseline, 10, and 21 days.

RESULTS

Golexanolone exhibited satisfactory safety and PK. Baseline characteristics were similar between the 12 and 33 patients randomized to placebo or golexanolone, respectively. By prespecified analyses, golexanolone was associated with directionally favourable changes vs. placebo in ESS (p = 0.047), MDF (p = 0.142) and DT/AB (p = 0.021). All patients also showed directionally favourable changes in CRT, PHES and ANT, but with no statistical difference between golexanolone and placebo. Post hoc analyses taking into account the variability and improvement in CRT, PHES and ANT observed between screening and baseline suggested an efficacy signal by cognitive measures as well.

CONCLUSION

Golexanolone was well tolerated and associated with improvement in cognitive performance. These results implicate GABA-A receptor-modulating neurosteroids in the pathogenesis of HE and support the therapeutic potential of golexanolone.

LAY SUMMARY

Many patients with cirrhosis experience subtle but disabling cognitive problems, including sleepiness and poor attention span, that impair their ability to be gainfully employed or carry out activities of daily living. This pilot study tested the hypothesis that these problems with cognition, for which there is no approved treatment, might be improved by an experimental drug, golexanolone, designed to normalize the function of receptors which inhibit brain function. The results of this study suggest that golexanolone is well tolerated and may improve cognition, as reflected by measures of sleepiness, attention span and brain wave activity, paving the way for future larger studies of this promising experimental drug.

CLINICAL TRIAL REGISTRATION NUMBER

EudraCT 2016-003651-30.

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.

Clinical, neuropsychological and neurophysiological indices and predictors of hepatic encephalopathy (HE)

BACKGROUND AND AIMS

The occurrence of overt hepatic encephalopathy (HE) marks a significant progression in the natural history of liver disease. The aims of the present study were to: 1) describe a large cohort of patients with cirrhosis in terms of neuropsychological or neurophysiological HE indices, and 2) test if the severity of liver disease and/or any such indices [Psychometric Hepatic Encephalopathy Score (PHES), Scan test, electroencephalography (EEG)] predicted mortality/HE risk in a subgroup of such cohort.

METHOD

Four hundred and sixty-one patients with cirrhosis (59 ± 10 years; 345 males) were included; information on previous overt HE episodes was available in 407. Follow-up information on mortality/HE-related hospitalization in 134/127 respectively. Information on previous overt HE episodes and both mortality and HE-related hospitalization over the follow-up in 124.

RESULTS

Patients with a history of overt HE (60%) had poorer liver function, worse neuropsychiatric indices, higher ammonia levels and higher prevalence of portal-systemic shunt. The risk of HE-related hospitalization over the follow-up was higher in patients with higher MELD score and worse Scan performance. Mortality was higher in those with higher MELD. Among patients without a history of overt HE, those with worse PHES had higher HE risk. Among patients with a history, those with higher MELD, better PHES and worse Scan performance had higher HE risk.

CONCLUSIONS

In patients without previous overt HE episodes, neuropsychological and neurophysiological tests predict HE, while in those with previous overt HE episodes, HE development largely depends on the severity of liver dysfunction.

Validation of a Simple Quality-of-Life Score for Identification of Minimal and Prediction of Overt Hepatic Encephalopathy

Minimal hepatic encephalopathy (MHE) is underdiagnosed because most clinics refrain from psychometric testing. Diagnostic activities need to go up so patients with MHE can get the treatment their condition requires. The sickness impact profile questionnaire for covert hepatic encephalopathy (SIPCHE) score is based on quality‐of‐life outcomes and has been proposed as a simple, patient‐administered diagnostic score for grade 1 and MHE. Validate the SIPCHE for MHE identification and overt hepatic encephalopathy (OHE) prediction. 110 patients with liver cirrhosis (age 60 years, Model for End‐Stage Liver Disease score of 11.4, 80% blue‐collar) provided information for SIPCHE scoring: gender, age, and four SIP statements: “I do not maintain balance (physically),” “I act irritable or impatient with myself,” “I am not doing any of the usual physical recreation or activities,” and “I am eating much less than usual.” MHE was diagnosed using an abnormal continuous reaction time test and/or portosystemic encephalopathy syndrome test score. Patients were followed for 2.7 years on average. SIPCHE score positivity had high sensitivity (82%) but low specificity (38%) for MHE detection. Patients with an abnormal SIPCHE had a higher incidence of OHE during follow‐up (35% vs. 14%, P = 0.05). OHE prediction sensitivity was 87% and exclusion sensitivity was 85%. The patients with an abnormal SIPCHE had twice as many subsequent episodes of OHE, and despite their high mortality, also a higher risk. An abnormal SIPCHE had a high sensitivity and low specificity for MHE identification. An abnormal SIPCHE was associated with a more than doubled risk of OHE, even with death as a competing event. SIPCHE could be used as a high‐sensitivity, low‐cost, surrogate marker of MHE in clinics without availability of psychometric tests and allow more patients to benefit from anti‐MHE treatment.

Important Unresolved Questions in the Management of Hepatic Encephalopathy: An ISHEN Consensus

Management of hepatic encephalopathy (HE) remains challenging from a medical and psychosocial perspective. Members of the International Society for Hepatic Encephalopathy and Nitrogen Metabolism recognized 5 key unresolved questions in HE management focused on (i) driving, (ii) ammonia levels in clinical practice, (iii) testing strategies for covert or minimal HE, (iv) therapeutic options, and (v) nutrition and patient-reported outcomes. The consensus document addresses these topical issues with a succinct review of the literature and statements that critically evaluate the current science and practice, laying the groundwork for future investigations.

Liver-related effects of chronic hepatitis C antiviral treatment

More than five years ago, the treatment of hepatitis C virus infection was revolutionized with the introduction of all-oral direct-acting antiviral (DAA) drugs. They proved highly efficient in curing patients with chronic hepatitis C (CHC), including patients with cirrhosis. The new DAA treatments were alleged to induce significant improvements in clinical outcome and prognosis, but the exact cause of the expected benefit was unclear. Further, little was known about how the underlying liver disease would be affected during and after viral clearance. In this review, we describe and discuss the liver-related effects of the new treatments in regards to both pathophysiological aspects, such as macrophage activation, and the time-dependent effects of therapy, with specific emphasis on inflammation, structural liver changes, and liver function, as these factors are all related to morbidity and mortality in CHC patients. It seems clear that antiviral therapy, especially the achievement of a sustained virologic response has several beneficial effects on liver-related parameters in CHC patients with advanced liver fibrosis or cirrhosis. There seems to be a time-dependent effect of DAA therapy with viral clearance and the resolution of liver inflammation followed by more discrete changes in structural liver lesions. These improvements lead to favorable effects on liver function, followed by an improvement in cognitive dysfunction and portal hypertension. Overall, the data provide knowledge on the several beneficial effects of DAA therapy on liver-related parameters in CHC patients suggesting short- and long-term improvements in the underlying disease with the promise of an improved long-term prognosis.

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.

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.

Diagnosis of covert hepatic encephalopathy: a multi-center study testing the utility of single versus combined testing

Covert hepatic encephalopathy (CHE) affects cognition in a multidimensional fashion. Current guidelines recommend performing Psychometric Hepatic Encephalopathy Score (PHES) and a second test to diagnose CHE for multi-center trials. We aimed to determine if a two-test combination strategy improved CHE diagnosis agreement, and accuracy to predict overt hepatic encephalopathy (OHE), compared to single testing. Cirrhotic outpatients without baseline OHE performed PHES, Inhibitory Control Test (ICT), and Stroop EncephAlapp (StE) at three centers. Patients were followed for OHE development. Areas under the receiver operation characteristic curve (AUROC) were calculated. We included 437 patients (399 with follow-up data). CHE prevalence varied with testing strategy: PHES+ICT 18%, ICT + StE 25%, PHES+StE 29%, ICT 35%, PHES 37%, and StE 54%. Combination with best test agreement was PHES+StE (k = 0.34). Sixty patients (15%) developed OHE. Although CHE by StE showed the highest sensitivity to predict OHE, PHES and PHES+StE were more accurate at the expense of a lower sensitivity (55%, AUROC: 0.587; 36%, AUROC: 0.629; and 29%, AUROC: 0.623; respectively). PHES+ICT was the most specific (85%) but all strategies including ICT showed sensitivities in the 33-45% range. CHE diagnosis by PHES (HR = 1.79, p = 0.04), StE (HR = 1.69, p = 0.04), and PHES+StE (HR = 1.72, p = 0.04), were significant OHE predictors even when adjusted for prior OHE and MELD. Our results demonstrate that combined testing decreases CHE prevalence without improving the accuracy of OHE prediction. Testing with PHES or StE alone, or a PHES+StE combination, is equivalent to diagnose CHE and predict OHE development in a multi-center setting.

Prognostic Implications of Minimal/Covert Hepatic Encephalopathy: Large-scale Validation Cohort Studies

Minimal or Covert Hepatic Encephalopathy (MHE/CHE), the preclinical phase of Hepatic Encephalopathy (HE), is strongly associated with poorer Quality of Life (QOL), Overt HE (OHE), and death. Several diagnostic tests have been developed that have prognostic value in predicting clinical outcomes such as OHE, cirrhosis progression, and death. However, dispute among clinicians and HE researchers have kept its application largely underutilized. Current issues contributing to the confusion include: lack of a formal definition for CHE, uncertainty of which diagnostic tools to use, and whether one or two abnormal tests are required for a diagnosis. Due to this misunderstanding, the aims of this review were to consolidate large-scale (n ≥ 100) validation studies in order to discuss these obstacles and make recommendations for improving our approach to MHE/CHE. The studies included in this review are a great resource for initiating a unified effort for advancement in HE, and as such, it is our hope that this will drive progress toward common goals that will permanently improve the lives of patients with cirrhosis.

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.

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.

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.

In Patients With Cirrhosis, Driving Simulator Performance Is Associated With Real-life Driving

BACKGROUND & AIMS

Minimal hepatic encephalopathy (MHE) has been linked to higher real-life rates of automobile crashes and poor performance in driving simulation studies, but the link between driving simulator performance and real-life automobile crashes has not been clearly established. Furthermore, not all patients with MHE are unsafe drivers, but it is unclear how to distinguish them from unsafe drivers. We investigated the link between performance on driving simulators and real-life automobile accidents and traffic violations. We also aimed to identify features of unsafe drivers with cirrhosis and evaluated changes in simulated driving skills and MHE status after 1 year.

METHODS

We performed a study of outpatients with cirrhosis (n = 205; median 55 years old; median model for end-stage liver disease score, 9.5; none with overt hepatic encephalopathy or alcohol or illicit drug use within previous 6 months) seen at the Virginia Commonwealth University and McGuire Veterans Administration Medical Center, from November 2008 through April 2014. All participants were given paper-pencil tests to diagnose MHE (98 had MHE; 48%), and 163 patients completed a standardized driving simulation. Data were collected on traffic violations and automobile accidents from the Virginia Department of Motor Vehicles and from participants' self-assessments when they entered the study, and from 73 participants 1 year later. Participants also completed a questionnaire about alcohol use and cessation patterns. The driving simulator measured crashes, run-time, road center and edge excursions, and illegal turns during navigation; before and after each driving simulation session, patients were asked to rate their overall driving skills. Drivers were classified as safe or unsafe based on crashes and violations reported on official driving records; simulation results were compared with real-life driving records. Multivariable regression analyses of real-life crashes and violations was performed using data on demographics, cirrhosis details, MHE status, and alcohol cessation patterns, at baseline and at 1 year.

RESULTS

Drivers categorized as unsafe had more crashes and made more illegal turns on the driving simulator than drivers categorized as safe; a higher proportion of subjects with MHE were categorized as unsafe drivers at baseline (16%) than subjects without MHE (7%; P = .02), and at 1-year follow-up (18% vs 0%; P = .02). Alcohol cessation within <1 year and illegal turns during simulator navigation tasks were associated with real-life automobile crashes and MHE in regression analysis; road edge excursions in the simulator were associated with real-life traffic violations. Personal assessment of driving skills improved after each simulation episode.

CONCLUSIONS

In a study of 205 patients with cirrhosis, we associated results from driving simulation tests with real-life driving records and MHE. Traffic safety counseling should focus on patients with cirrhosis who recently quit consuming alcohol and perform poorly on driving simulation.

Clinical and Pathophysiological Characteristics of Cirrhotic Patients with Grade 1 and Minimal Hepatic Encephalopathy

Background and Aims

EASL/AASLD hepatic encephalopathy (HE) guidelines proposed the alternative use of the term ‘Covert HE’ combining minimal HE (mHE) and Grade 1 HE into a single entity. However, longitudinal data to indicate that these are indeed a single entity are lacking. The aims of this study were to determine whether the occurrence of complications of cirrhosis requiring hospital admission and mortality were similar in these sub-groups of patients.

Methods

Clinically-stable cirrhotic patients (n = 106) with no previous history of ‘Overt HE’ were included over a 2-year period and classified as having no HE (n = 23), mHE (n = 39) or Grade 1 HE (n = 44). Standard biochemistry, venous ammonia, bacterial DNA and neutrophil function were measured at inclusion and the patients were followed for a mean of 230±95 days.

Results

Patients with Grade 1 HE had significantly more complications requiring hospitalisation (infection 9/18/34%; HE 4/8/18%; other 13/10/11%; P = 0.02) and significantly greater mortality (4/5/20%; P = 0.04) compared to patients with no HE or mHE respectively. Patients with mHE and grade 1 HE had similar ammonia levels, but higher than the no HE group (P<0.001). MELD score was similar between groups but Grade 1 HE patients had increased frequency of bacterial translocation (P = 0.06) and neutrophil spontaneous respiratory burst (P = 0.02) compared to patients with mHE.

Conclusions

The results of this study show for the first time that ‘Covert HE’ is a heterogeneous entity with significantly greater hospitalisations and mortality in the Grade 1 HE patients compared with mHE. Further prospective longer-term studies are required before EASL/AASLD guidance is fully implemented.

Altered metal metabolism in patients with HCV-related cirrhosis and hepatic encephalopathy

Dysfunctional metal homeostasis contributes to oxidative stress and neuronal damage. These have been implicated in hepatic encephalopathy pathogenesis. To investigate whether altered metal metabolism is associated with hepatic encephalopathy. Twenty-one controls and 34 HCV-cirrhotic patients (ENC/NEC patients according to presence/absence of previous overt episodes of hepatic encephalopathy) and a control group were studied. Serum iron, copper, ceruloplasmin, ceruloplasmin activity, transferrin, and ceruloplasmin/transferrin ratio were determined. Neuropsychological tests were performed by the repeatable battery of neuropsychological status. Magnetic resonance assessed basal ganglia volumes and metal deposition (pallidal index and T2*). Cirrhotic patients performed worse than controls at cognitive tests, especially ENC patients,. At biochemical analysis copper concentrations, ceruloplasmin activity and transferrin levels were lower in ENC than in NEC patients and controls (p < 0.05 and p < 0.01, respectively). Ceruloplasmin/transferrin ratio was higher in ENC compared to NEC patients (p < 0.05), and controls (p < 0.01). By brain magnetic resonance, ENC patients showed reduced caudate and globus pallidus volumes compared to controls (p < 0.05), and ENC and NEC patients an increased pallidal index compared to controls (p < 0.01). In ENC patients, ceruloplasmin activity correlated with caudate volume and pallidal index (ρ = 0.773 and ρ = -0.683, p < 0.05). Altered metal metabolism likely contributes to cirrhotic hepatic encephalopathy.