Hepatic Encephalopathy-the Old and the New

Altered Mental Status in the Solid-Organ Transplant Recipient

Patients undergoing solid-organ transplantation (SOT) face a tumultuous journey. Prior to transplant, their medical course is characterized by organ dysfunction, diminished quality of life, and reliance on organ support, all of which are endured in hopes of reaching the haven of organ transplantation. Peritransplant altered mental status may indicate neurologic insults acquired during transplant and may have long-lasting consequences. Even years after transplant, these patients are at heightened risk for neurologic dysfunction from a myriad of metabolic, toxic, and infectious causes. This review provides a comprehensive examination of causes, diagnostic approaches, neuroimaging findings, and management strategies for altered mental status in SOT recipients. Given their complexity and the numerous etiologies for neurologic dysfunction, liver transplant patients are a chief focus in this review; however, we also review lesser-known contributors to neurological injury across various transplant types. From hepatic encephalopathy to cerebral edema, seizures, and infections, this review highlights the importance of recognizing and managing pre- and posttransplant neurological complications to optimize patient outcomes.

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Alcohol and the central nervous system

Ethanol use is common to most cultures but with varying doses and to varying extents. While research has focused on the effects on the liver, alcohol exerts a range of actions on the function and structure of the nervous system. In the central nervous system (CNS) it can provoke or exacerbate neurological and psychiatric disease; its effects on the peripheral nervous system are not included in this review. Sustained alcohol intake can predispose to acute neurochemical changes which, with continued ingestion and incomplete treatment, can lead to chronic structural changes in the CNS: these include generalised cortical and cerebellar atrophy, amnesic syndromes such as Korsakoff's syndrome, and specific white matter disorders such as central pontine myelinolysis and Marchiafava-Bignami syndrome. Alcohol in pregnancy commonly and significantly affects fetal health, though this receives less medical and political attention than other causes of fetal harm. This review looks at the range of disorders that can follow acute or chronic alcohol use, and how these should be managed, and we provide a practical overview on how neurologists might diagnose and manage alcohol addiction.

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.

Bile Acid Signaling in Neurodegenerative and Neurological Disorders

Bile acids are commonly known as digestive agents for lipids. The mechanisms of bile acids in the gastrointestinal track during normal physiological conditions as well as hepatic and cholestatic diseases have been well studied. Bile acids additionally serve as ligands for signaling molecules such as nuclear receptor Farnesoid X receptor and membrane-bound receptors, Takeda G-protein-coupled bile acid receptor and sphingosine-1-phosphate receptor 2. Recent studies have shown that bile acid signaling may also have a prevalent role in the central nervous system. Some bile acids, such as tauroursodeoxycholic acid and ursodeoxycholic acid, have shown neuroprotective potential in experimental animal models and clinical studies of many neurological conditions. Alterations in bile acid metabolism have been discovered as potential biomarkers for prognosis tools as well as the expression of various bile acid receptors in multiple neurological ailments. This review explores the findings of recent studies highlighting bile acid-mediated therapies and bile acid-mediated signaling and the roles they play in neurodegenerative and neurological diseases.

Language impairment in adults with end-stage liver disease: application of natural language processing towards patient-generated health records

End-stage liver disease (ESLD) is associated with cognitive impairment ranging from subtle alterations in attention to overt hepatic encephalopathy that resolves after transplant. Natural language processing (NLP) may provide a useful method to assess cognitive status in this population. We identified 81 liver transplant recipients with ESLD (4/2013–2/2018) who sent at least one patient-to-provider electronic message pre-transplant and post-transplant, and matched them 1:1 to “healthy” controls—who had similar disease, but had not been evaluated for liver transplant—by age, gender, race/ethnicity, and liver disease. Messages written by patients pre-transplant and post-transplant and controls was compared across 19 NLP measures using paired Wilcoxon signed-rank tests. While there was no difference overall in word length, patients with Model for End-Stage Liver Disease Score (MELD) ≥ 30 (n = 31) had decreased word length in pre-transplant messages (3.95 [interquartile range (IQR) 3.79, 4.14]) compared to post-transplant (4.13 [3.96, 4.28], p = 0.01) and controls (4.2 [4.0, 4.4], p = 0.01); there was no difference between post-transplant and controls (p = 0.4). Patients with MELD ≥ 30 had fewer 6+ letter words in pre-transplant messages (19.5% [16.4, 25.9] compared to post-transplant (23.4% [20.0, 26.7] p = 0.02) and controls (25.0% [19.2, 29.4]; p = 0.01). Overall, patients had increased sentence length pre-transplant (12.0 [9.8, 13.7]) compared to post-transplant (11.0 [9.2, 13.3]; p = 0.046); the same was seen for MELD ≥ 30 (12.3 [9.8, 13.7] pre-transplant vs. 10.8 [9.6, 13.0] post-transplant; p = 0.050). Application of NLP to patient-generated messages identified language differences—longer sentences with shorter words—that resolved after transplant. NLP may provide opportunities to detect cognitive impairment in ESLD.

Acute-on-chronic liver failure: Objective admission and support criteria in the intensive care unit

Cirrhosis is a leading cause of morbidity and mortality throughout the world. Significant complications include variceal bleeding, hepatic encephalopathy, hepatorenal syndrome, and infection. When these complications are severe, admission to the intensive care unit (ICU) is often required for organ support and management. Intensive care therapy can also serve as a bridge to liver transplantation. Along with decompensation of cirrhosis, the concept of acute-on-chronic liver failure (ACLF) has emerged. This involves an acute precipitating event, such as the development of infection in a patient with cirrhosis, which leads to acute deterioration of hepatic function and extrahepatic organ failure. Extrahepatic complications often include renal, cardiovascular, and respiratory failures. Patients with significant extrahepatic and hepatic failures need ICU admission for organ support. Again, in patients who are deemed suitable liver transplant candidates, intensive care management may allow bridging to liver transplantation. However, patients with a Chronic Liver Failure Consortium ACLF score greater than 70 at 48 to 72 hours post-ICU admission do not seem to benefit from ongoing intensive support and a palliative approach may be more appropriate.