Cognitive impairment in liver transplant candidates: The role of blood ammonia level and three-point evaluation of brain MRI

BACKGROUND: Cognitive impairment (CI) is common in patients with alcohol-use disorder (AUD)-related liver cirrhosis, especially those awaiting liver transplantation (LT). There are conflicting results in terms of the role of hepatic encephalopathy (HE) in CI development and persistence. OBJECTIVES: This study investigated the impact of hyperammonemia on CI and evaluated the role of routine magnetic resonance imaging (MRI) in detecting CI among patients with AUD-related cirrhosis listed for LT at a single center. MATERIAL AND METHODS: Fifty-two adults (36 males, 69%) with AUD-related liver cirrhosis (mean age: 51 ±11 years; mean Model for End-Stage Liver Disease (MELD) score 16 ±6) were evaluated. Cognitive function was assessed using the Addenbrooke's Cognitive Examination III (ACE-III), with scores below 82 indicating probable dementia. Magnetic resonance imaging evaluations focused on cortical-subcortical atrophy, vascular-origin changes, and chronic HE. RESULTS: Magnetic resonance imaging revealed HE-related changes in 38 patients (73%), vascular-origin changes in 32 patients (62%), and cortical-subcortical atrophy in 15 patients (29%). Cognitive impairment was present in 46 patients (88%), with 30 (58%) suspected of having dementia. Patients with MRI evidence of HE scored lower in the ACE III language subdomain (p = 0.032) and tended toward a higher Child-Pugh classification (p = 0.083). No significant differences were found in ACE-III results or clinical data between patients with and without vascular-origin changes or cortical-subcortical atrophy. Additionally, no correlations were observed between radiological findings, ammonia levels, ACE-III scores, and liver-related mortality. CONCLUSIONS: These findings reveal a high prevalence of CI and significant MRI abnormalities in AUD patients awaiting LT. Further studies are needed to clarify the role of routine MRI in detecting cognitive deficits.