title: Focal cortical damage parallels cognitive impairment in minimal hepatic encephalopathy.
abstract: 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.
authors.affiliation: Fundación Investigación Hospital Clínico Universitario de Valencia-INCLIVA, Spain.
authors.forename: Carmina
authors.initials: C
authors.lastname: Montoliu
authors.forename: Gabriel
authors.initials: G
authors.lastname: Gonzalez-Escamilla
authors.forename: Mercedes
authors.initials: M
authors.lastname: Atienza
authors.forename: Amparo
authors.initials: A
authors.lastname: Urios
authors.forename: Olga
authors.initials: O
authors.lastname: Gonzalez
authors.forename: Abdallah
authors.initials: A
authors.lastname: Wassel
authors.forename: Roberto
authors.initials: R
authors.lastname: Aliaga
authors.forename: Remedios
authors.initials: R
authors.lastname: Giner-Duran
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Serra
authors.forename: Jose M
authors.initials: JM
authors.lastname: Rodrigo
authors.forename: Vicente
authors.initials: V
authors.lastname: Belloch
authors.forename: Vicente
authors.initials: V
authors.lastname: Felipo
authors.forename: Jose L
authors.initials: JL
authors.lastname: Cantero
mesh_terms: D002540:Cerebral Cortex / Q000473:pathology*; D003072:Cognition Disorders / Q000209:etiology / Q000473:pathology*; D042241:Early Diagnosis; D005260:Female; D006501:Hepatic Encephalopathy / Q000150:complications / Q000473:pathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests