title: Longitudinal brain white matter alterations in minimal hepatic encephalopathy before and after liver transplantation.
abstract: Cerebral edema is the common pathogenic mechanism for cognitive impairment in minimal hepatic encephalopathy. Whether complete reversibility of brain edema, cognitive deficits, and their associated imaging can be achieved after liver transplantation remains an open question. To characterize white matter integrity before and after liver transplantation in patients with minimal hepatic encephalopathy, multiple diffusivity indices acquired via diffusion tensor imaging was applied. Twenty-eight patients and thirty age- and sex-matched healthy volunteers were included. Multiple diffusivity indices were obtained from diffusion tensor images, including mean diffusivity, fractional anisotropy, axial diffusivity and radial diffusivity. The assessment was repeated 6-12 month after transplantation. Differences in white matter integrity between groups, as well as longitudinal changes, were evaluated using tract-based spatial statistical analysis. Correlation analyses were performed to identify first scan before transplantation and interval changes among the neuropsychiatric tests, clinical laboratory tests, and diffusion tensor imaging indices. After transplantation, decreased water diffusivity without fractional anisotropy change indicating reversible cerebral edema was found in the left anterior cingulate, claustrum, postcentral gyrus, and right corpus callosum. However, a progressive decrease in fractional anisotropy and an increase in radial diffusivity suggesting demyelination were noted in temporal lobe. Improved pre-transplantation albumin levels and interval changes were associated with better recoveries of diffusion tensor imaging indices. Improvements in interval diffusion tensor imaging indices in the right postcentral gyrus were correlated with visuospatial function score correction. In conclusion, longitudinal voxel-wise analysis of multiple diffusion tensor imaging indices demonstrated different white matter changes in minimal hepatic encephalopathy patients. Transplantation improved extracellular cerebral edema and the results of associated cognition tests. However, white matter demyelination may advance in temporal lobe.
authors.affiliation: Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Wei-Che
authors.initials: WC
authors.lastname: Lin
authors.affiliation: Brain Research Center, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Kun-Hsien
authors.initials: KH
authors.lastname: Chou
authors.affiliation: Department of Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Chao-Long
authors.initials: CL
authors.lastname: Chen
authors.affiliation: Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan; Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Hsiu-Ling
authors.initials: HL
authors.lastname: Chen
authors.affiliation: Department of Neurology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Cheng-Hsien
authors.initials: CH
authors.lastname: Lu
authors.affiliation: Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Shau-Hsuan
authors.initials: SH
authors.lastname: Li
authors.affiliation: Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chu-Chung
authors.initials: CC
authors.lastname: Huang
authors.affiliation: Brain Research Center, National Yang-Ming University, Taipei, Taiwan; Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Ching-Po
authors.initials: CP
authors.lastname: Lin
authors.affiliation: Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Yu-Fan
authors.initials: YF
authors.lastname: Cheng
mesh_terms: D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006501:Hepatic Encephalopathy / Q000473:pathology* / Q000628:therapy; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D016031:Liver Transplantation / Q000379:methods*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D066127:White Matter / Q000254:growth & development* / Q000473:pathology* / Q000503:physiopathology