title: A longitudinal study of patients with cirrhosis treated with L-ornithine L-aspartate, examined with magnetization transfer, diffusion-weighted imaging and magnetic resonance spectroscopy.
abstract: The presence of overt hepatic encephalopathy (HE) is associated with structural, metabolic and functional changes in the brain discernible by use of a variety of magnetic resonance (MR) techniques. The changes in patients with minimal HE are less well documented. Twenty-two patients with well-compensated cirrhosis, seven of whom had minimal HE, were examined with cerebral 3 Tesla MR techniques, including T1- and T2-weighted, magnetization transfer and diffusion-weighted imaging and proton magnetic resonance spectroscopy sequences. Studies were repeated after a 4-week course of oral L-ornithine L-aspartate (LOLA). Results were compared with data obtained from 22 aged-matched healthy controls. There was no difference in mean total brain volume between patients and controls at baseline. Mean cerebral magnetization transfer ratios were significantly reduced in the globus pallidus and thalamus in the patients with cirrhosis irrespective of neuropsychiatric status; the mean ratio was significantly reduced in the frontal white matter in patients with minimal HE compared with healthy controls but not when compared with their unimpaired counterparts. There were no significant differences in either the median apparent diffusion coefficients or the mean fractional anisotropy, calculated from the diffusion-weighted imaging, or in the mean basal ganglia metabolite ratios between patients and controls. Psychometric performance improved in 50 % of patients with minimal HE following LOLA, but no significant changes were observed in brain volumes, cerebral magnetization transfer ratios, the diffusion weighted imaging variables or the cerebral metabolite ratios. MR variables, as applied in this study, do not identify patients with minimal HE, nor do they reflect changes in psychometric performance following LOLA.
authors.affiliation: Liver Unit, Division of Digestive Health, Department of Surgery and Cancer, Imperial College London, 10th Floor QEQM Wing, St Mary's Hospital, Praed Street, London, W2 1NY, UK.|Robert Steiner MRI Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Imperial College London, London, UK.
authors.forename: Vijay P B
authors.initials: VP
authors.lastname: Grover
authors.affiliation: Liver Unit, Division of Digestive Health, Department of Surgery and Cancer, Imperial College London, 10th Floor QEQM Wing, St Mary's Hospital, Praed Street, London, W2 1NY, UK.|Robert Steiner MRI Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Imperial College London, London, UK.
authors.forename: Mark J W
authors.initials: MJ
authors.lastname: McPhail
authors.affiliation: Liver Unit, Division of Digestive Health, Department of Surgery and Cancer, Imperial College London, 10th Floor QEQM Wing, St Mary's Hospital, Praed Street, London, W2 1NY, UK.|Robert Steiner MRI Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Imperial College London, London, UK.
authors.forename: Marzena
authors.initials: M
authors.lastname: Wylezinska-Arridge
authors.affiliation: Liver Unit, Division of Digestive Health, Department of Surgery and Cancer, Imperial College London, 10th Floor QEQM Wing, St Mary's Hospital, Praed Street, London, W2 1NY, UK.
authors.forename: Mary M E
authors.initials: MM
authors.lastname: Crossey
authors.affiliation: Liver Unit, Division of Digestive Health, Department of Surgery and Cancer, Imperial College London, 10th Floor QEQM Wing, St Mary's Hospital, Praed Street, London, W2 1NY, UK.|Robert Steiner MRI Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Imperial College London, London, UK.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Fitzpatrick
authors.affiliation: Liver Unit, Division of Digestive Health, Department of Surgery and Cancer, Imperial College London, 10th Floor QEQM Wing, St Mary's Hospital, Praed Street, London, W2 1NY, UK.
authors.forename: Louise
authors.initials: L
authors.lastname: Southern
authors.affiliation: Centre for Ageing and Health, Newcastle University, Newcastle-upon-Tyne, UK.
authors.forename: Brian K
authors.initials: BK
authors.lastname: Saxby
authors.affiliation: Liver Unit, Division of Digestive Health, Department of Surgery and Cancer, Imperial College London, 10th Floor QEQM Wing, St Mary's Hospital, Praed Street, London, W2 1NY, UK.
authors.forename: Nicola A
authors.initials: NA
authors.lastname: Cook
authors.affiliation: The Foundation for Liver Research, Institute of Hepatology, 69-75 Chenies Mews, London, WC1E 6HX, UK.
authors.forename: I Jane
authors.initials: IJ
authors.lastname: Cox
authors.affiliation: Robert Steiner MRI Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Imperial College London, London, UK.
authors.forename: Adam D
authors.initials: AD
authors.lastname: Waldman
authors.affiliation: Division of Brain Sciences, Hammersmith Hospital Campus, Imperial College London, London, UK.
authors.forename: Novraj S
authors.initials: NS
authors.lastname: Dhanjal
authors.affiliation: Liver Unit, Division of Digestive Health, Department of Surgery and Cancer, Imperial College London, 10th Floor QEQM Wing, St Mary's Hospital, Praed Street, London, W2 1NY, UK.|Robert Steiner MRI Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Imperial College London, London, UK.
authors.forename: Aluel
authors.initials: A
authors.lastname: Bak-Bol
authors.affiliation: The Foundation for Liver Research, Institute of Hepatology, 69-75 Chenies Mews, London, WC1E 6HX, UK.
authors.forename: Roger
authors.initials: R
authors.lastname: Williams
authors.affiliation: UCL Institute for Liver & Digestive Health, Division of Medicine, Royal Free Campus, University College London, London, UK.
authors.forename: Marsha Y
authors.initials: MY
authors.lastname: Morgan
authors.affiliation: Liver Unit, Division of Digestive Health, Department of Surgery and Cancer, Imperial College London, 10th Floor QEQM Wing, St Mary's Hospital, Praed Street, London, W2 1NY, UK. s.taylor-robinson@imperial.ac.uk.
authors.forename: Simon D
authors.initials: SD
authors.lastname: Taylor-Robinson
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging*; D003071:Cognition / Q000502:physiology; D038524:Diffusion Magnetic Resonance Imaging; D004151:Dipeptides / Q000627:therapeutic use*; D005260:Female; D006501:Hepatic Encephalopathy / Q000000981:diagnostic imaging / Q000188:drug therapy*; D006801:Humans; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging / Q000188:drug therapy*; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D011594:Psychometrics
chemical_list: D004151:Dipeptides; C002939:ornithylaspartate
keywords: Cirrhosis; Hepatic encephalopathy; Magnetic resonance imaging; Spectroscopy