Little attention has been paid to cortical integrity in patients with minimal
hepatic encephalopathy (MHE), although cognitive functions affected in early stages of
liver disease are mainly allocated in different neocortical structures. Here we used cortical surface-based analysis techniques to investigate if patterns of
cortical thinning accompany the mildest form of HE. To aim this goal, cortical thickness obtained from high-resolution 3T magnetic resonance imaging (MRI) was measured in patients with no MHE (NMHE), MHE, and healthy controls. Further correlation analyses were performed to examine whether scores in the critical flicker frequency (CFF) test, and blood
ammonia levels accounted for the loss of cortical integrity in different stages of
liver disease. Finally, we assessed group differences in volume of different subcortical regions and their potential relationships with CFF scores/blood
ammonia levels. Results showed a focal thinning of the superior temporal cortex and precuneus in MHE patients when compared with NMHE and controls. Relationships between blood
ammonia levels and cortical thickness of the calcarine sulcus accounted for impaired visual judgment in patients with MHE when compared to NMHE. Regression analyses between cortical thickness and CFF predicted differences between controls and the two groups of HE patients, but failed to discriminate between patients with NMHE and MHE. Taking together, these findings provide the first report of
cortical thinning in MHE patients, and they yield novel insights into the neurobiological basis of
cognitive impairment associated with early stages of
liver diseases.