Brain Training with Video Games in Covert Hepatic Encephalopathy

Changes in dynamic and static brain fluctuation distinguish minimal hepatic encephalopathy and cirrhosis patients and predict the severity of liver damage

Purpose

Minimal hepatic encephalopathy (MHE) is characterized by mild neuropsychological and neurophysiological alterations that are not detectable by routine clinical examination. Abnormal brain activity (in terms of the amplitude of low-frequency fluctuation (ALFF) has been observed in MHE patients. However, little is known concerning temporal dynamics of intrinsic brain activity. The present study aimed to investigate the abnormal dynamics of brain activity (dynamic ALFF; dALFF) and static measures [static ALFF; (sALFF)] in MHE patients and to strive for a reliable imaging neuromarkers for distinguishing MHE patients from cirrhosis patients. In addition, the present study also investigated whether intrinsic brain activity predicted the severity of liver damage.

Methods

Thirty-four cirrhosis patients with MHE, 28 cirrhosis patients without MHE, and 33 age-, sex-, and education-matched healthy controls (HCs) underwent resting-state magnetic resonance imaging (rs-fMRI). dALFF was estimated by combining the ALFF method with the sliding-window method, in which temporal variability was quantized over the whole-scan timepoints and then compared among the three groups. Additionally, dALFF, sALFF and both two features were utilized as classification features in a support vector machine (SVM) to distinguish MHE patients from cirrhosis patients. The severity of liver damage was reflected by the Child–Pugh score. dALFF, sALFF and both two features were used to predict Child–Pugh scores in MHE patients using a general linear model.

Results

Compared with HCs, MHE patients showed significantly increased dALFF in the left inferior occipital gyrus, right middle occipital gyrus, and right insula; increased dALFF was also observed in the right posterior lobe of the cerebellum (CPL) and right thalamus. Compared with HCs, noMHE patients exhibited decreased dALFF in the right precuneus. In contrast, compared with noMHE patients, MHE patients showed increased dALFF in the right precuneus, right superior frontal gyrus, and right superior occipital gyrus. Furthermore, the increased dALFF values in the left precuneus were positively associated with poor digit-symbol test (DST) scores (r = 0.356, p = 0.038); however, dALFF in the right inferior temporal gyrus (ITG) was negatively associated with the number connection test–A (NCT-A) scores (r = -0.784, p = 0.000). A significant positive correlation was found between dALFF in the left inferior occipital gyrus (IOG) and high blood ammonia levels (r = 0.424, p = 0.012). Notably, dALFF values yielded a higher classification accuracy than sALFF values in distinguishing MHE patients from cirrhosis patients. Importantly, the dALFF values predicted the Child–Pugh score (r = 0.140, p = 0.030), whereas sALFF values did not in the current dataset. Combining two features had high accuracy in classification in distinguishing MHE patients from cirrhotic patients and yielded prediction in the severity of liver damage.

Conclusion

These findings suggest that combining dALFF and sALFF features is a useful neuromarkers for distinguishing MHE patients from cirrhosis patients and highlights the important role of dALFF feature in predicting the severity of liver damage in MHE.

Progress in research of blood oxygen level dependent functional magnetic resonance imaging in cirrhotic patients with minimal hepatic encephalopathy

Hepatic encephalopathy (HE) is a neuropsychiatric syndrome that develops in patients with cirrhosis or other severe liver diseases. The incidence of minimal hepatic encephalopathy (MHE) is high, and MHE is often misdiagnosed because of its subclinical manifestations. MHE significantly reduces patients' quality of life and its prognosis is poor. Blood oxygen level dependent functional magnetic resonance imaging (BOLD-fMRI) has been used to explore the brain functional changes and to further understand pathophysiological mechanisms of brain disease. This article focuses on the progress in the research of BOLD-fMRI in cirrhotic patients with MHE with regard to its principles, categories, and post-processing algorithms.

Progressive Disruption of Dynamic Functional Network Connectivity in Patients With Hepatitis B Virus-related cirrhosis

BACKGROUND

The diseased-related dynamic functional network connectivity (dFNC) disruption and its relationship with cognitive impairment in hepatitis B virus-related cirrhosis (HBV-RC) patients with minimal hepatic encephalopathy (MHE) and no MHE (NMHE) remain unknown. This knowledge would help identify MHE pathophysiology and monitor disease progression in HBV-RC patients.

PURPOSE

To investigate the dFNC in patients with NMHE and MHE and the relationship between dFNC indices with the psychometric hepatic encephalopathy score (PHES).

STUDY TYPE

Prospective.

POPULATION

Thirty HBV-RC patients (including 17 NMHE and 13 MHE) and 38 healthy controls (HC).

FIELD STRENGTH/SEQUENCE

A 1.5 T MRI and gradient-echo echo-planar imaging and fast field echo three-dimensional T1-weighted imaging.

ASSESSMENT

The independent components, dFNC matrix and dFNC indices (mean dwell times [DT], number of states, number of transitions, and fraction time in each state), were obtained through GIFT package. Cognitive measurement and patients grouping were based on PHES tests.

STATISTICAL TESTS

One-way ANOVA, chi-square test, two-sample t-test, Kruskal-Wallis test, spearman's correlation analysis and the false discovery rate. Significance level: P < 0.05.

RESULTS

Compared to HC (21.1 ± 4.02), the DT of state 1 decreased in NMHE (9.0 ± 3.04, P = 0.062, 95% confidence interval [CI] is -0.65 to 24.88) and significantly in MHE stage (1.2 ± 1.01) and was significantly correlated with PHES (r = 0.5) for all patients. The DT of state 2 increased gradually in NMHE (75.2 ± 13.10, P = 0.052, 95% CI, -54.23 to 0.28) and significantly in MHE stage (94.6 ± 15.61) when compared to HC (48.2 ± 6.97). Moreover, the connectivity between cognitive control network (CCN) and visual network (VIS) in state 1 (0.7 ± 0.79) and between default mode (DMN) and VIS in state 2 (-0.2 ± 0.29) decreased significantly in MHE when compared to HC (0.1 ± 0.68 for CCN-VIS in state 1 and 0.1 ± 0.17 for DMN-VIS for state 2). DATA CONCLUSION: dFNC exhibited progressive impairment as the disease advances in patients with HBV-RC.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 2.

Predicting Hepatic Encephalopathy-Related Hospitalizations Using a Composite Assessment of Cognitive Impairment and Frailty in 355 Patients With Cirrhosis

INTRODUCTION

Hepatic encephalopathy (HE) is the most common potentially modifiable reason for admission in patients with cirrhosis. Cognitive and physical components of frailty have pathophysiologic rationale as risk factors for HE. We aimed to assess the utility of a composite score (MoCA-CFS) developed using the Montreal Cognitive Assessment (MoCA) and the Clinical Frailty Scale (CFS) for predicting HE admissions within 6 months.

METHODS

Consecutive adult patients with cirrhosis were followed for 6 months or until death/transplant. Patients with overt HE and dementia were excluded. Primary outcome was the prediction of HE-related admissions at 6 months.

RESULTS

A total of 355 patients were included; mean age 55.9 ± 9.6; 62.5% male; Hepatitis C and alcohol etiology in 64%. Thirty-six percent of patients had cognitive impairment according to the MoCA (≤24) and 14% were frail on the CFS (>4). The MoCA-CFS independently predicted HE hospitalization within 6 months, a MoCA-CFS score of 1 and 2 respectively increasing the odds of hospitalization by 3.3 (95% CI:1.5-7.7) and 5.7 (95% CI:1.9-17.3). HRQoL decreased with increasing MoCA-CFS. Depression and older age were independent predictors of a low MoCA.

CONCLUSIONS

Cognitive and physical frailty are common in patients with cirrhosis. In addition to being an independent predictor of HE admissions within 6 months, the MoCA-CFS composite score predicts impaired HRQoL and all-cause admissions within 6 months. These data support the predictive value of a "multidimensional" frailty tool for the prediction of adverse clinical outcomes and highlight the potential for a multi-faceted approach to therapy targeting cognitive impairment, physical frailty and depression.

Multimodal MR imaging in hepatic encephalopathy: state of the art

Hepatic encephalopathy (HE) is a neurological or neuropsychological complication due to liver failure or portosystemic shunting. The clinical manifestation is highly variable, which can exhibit mild cognitive or motor impairment initially, or gradually progress to a coma, even death, without treatment. Neuroimaging plays a critical role in uncovering the neural mechanism of HE. In particular, multimodality MR imaging is able to assess both structural and functional derangements of the brain with HE in focal or neural network perspectives. In recent years, there has been rapid development in novel MR technologies and applications to investigate the pathophysiological mechanism of HE. Therefore, it is necessary to update the latest MR findings regarding HE by use of multimodality MRI to refine and deepen our understanding of the neural traits in HE. Herein, this review highlights the latest MR imaging findings in HE to refresh our understanding of MRI application in HE.