Minimal Hepatic Encephalopathy: A Narrative Review

Minimal hepatic encephalopathy (MHE) is primarily a cognitive disorder linked to chronic liver disease that often remains underdiagnosed due to the subtlety of its clinical manifestations. These symptoms are frequently overlooked or dismissed as inconsequential in clinical practice, leading to many undiagnosed cases. The standard neurological examination is usually normal in individuals with MHE. Regular and systematic screening for MHE is essential for early detection, which can improve cognitive outcomes and prevent progression to a more serious and debilitating condition known as overt hepatic encephalopathy. The pathophysiology of MHE is very complex and multifactorial, involving several interacting mechanisms. Mainly, hyperammonemia, systemic inflammation, gut-derived neurotoxins, oxidative stress, and mitochondrial dysfunction are at its root. Any of these factors may interfere with the normal functioning of neurotransmitters, giving rise to the typical subtle cognitive impairments that are hallmarks of MHE. The Animal Naming Test and EncephalApp-Stroop test are practical, rapid, and easily administered tools for screening for minimal hepatic encephalopathy in outpatient and bedside settings. Emerging diagnostic technologies, including advanced neuroimaging techniques and novel biomarkers, have also been investigated and show promise for improving the early detection and diagnosis of MHE.