Lesnick, Timothy G.

AbstractIntroductionCerebrovascular lesions on MRI are common in Alzheimer's disease (AD) dementia, but less is known about their frequency and impact on dementia with Lewy bodies (DLB).MethodsWhite‐matter hyperintensities (WMHs) and infarcts on MRI were assessed in consecutive DLB (n = 81) and AD dementia (n = 240) patients and compared to age‐matched and sex‐matched cognitively normal subjects (CN) from a population‐based cohort.ResultsDLB had higher WMH volume compared to CN, and WMH volume was higher in the occipital and posterior periventricular regions in DLB compared to AD. Higher WMH volume was associated with history of cardiovascular disease and diabetes but not with clinical disease severity in DLB. Frequency of infarcts in DLB was not different from CN and AD dementia.DiscussionIn DLB, WMH volume is higher than AD and CN and appears to be primarily associated with history of vascular disease.

ABSTRACT Background The clinical course of dementia with Lewy bodies patients is heterogeneous. The ability to more accurately prognosticate survival is important. Objective The objective of this study was to investigate hippocampal volume as a predictor of survival in dementia with Lewy bodies patients. Methods Survival analysis for time from onset of cognitive symptoms to death was carried out using Cox proportional hazards models. Given their age and total intracranial volume, patients were dichotomized into low/medium (0%‐66.7%) and high (66. 7%‐100%) hippocampal volume categories. The models using these categories to predict survival were adjusted for field strength, APOE ε4 status, and estimated onset age of cognitive problems. Results We investigated 167 consecutive patients with dementia with Lewy bodies. The median age at MRI was 72 years (interquartile range 67‐76), and 80% were male. The median time from estimated first cognitive symptom to death was 7.4 years (interquartile range:5.7‐10.2). Lower hippocampal volumes were significantly associated with higher risk of death (hazard ratio 1.28; 95% confidence interval 1.04‐1.58; P = .024). The predicted median survival for participants with onset of cognitive symptoms at age 68 was 10.63 years (95% confidence interval 8.66‐14.54) for APOE ε4 negative, high hippocampal volume participants; 8.89 years (95% confidence interval 7.56‐12.36) for APOE ε4 positive, high hippocampal volume participants; 8.10 years (95% confidence interval 7.34‐11.08) for APOE ε4 negative, low/medium hippocampal volume participants; and 7.38 (95% confidence interval 6.74‐9.29) years for APOE ε4 positive, low/medium hippocampal volume participants. Conclusions Among patients with clinically diagnosed dementia with Lewy bodies, those with neuroimaging evidence of hippocampal atrophy have shorter survival times. © 2016 International Parkinson and Movement Disorder Society

PurposeRelaxation time constants are useful as markers of tissue properties. Imaging ex vivo tissue is done for research purposes; however, T1 relaxation time constants are altered by tissue fixation in a time‐dependent manner. This study investigates regional changes in T1 relaxation time constants in ex vivo brain tissue over 6 months of fixation.MethodsFive ex vivo human brain hemispheres in 10% formalin were scanned over 6 months. Mean T1 relaxation time constants were measured in regions of interest (ROIs) representing gray matter (GM) and white matter (WM) regions and analyzed as a function of fixation time.ResultsCortical GM ROIs had longer T1 relaxation time constants than WM ROIs; the thalamus had T1 relaxation time constants similar to those of WM ROIs. T1 relaxation time constants showed rapid shortening within the first 6 weeks after fixation followed by a slower rate of decline.ConclusionBoth GM and WM T1 relaxation time constants of fixed brain tissue show rapid decline within the first 6 weeks after autopsy and slow by 6 months. This information is useful for optimizing MR imaging acquisition parameters according to fixation time for ex vivo brain imaging studies. Magn Reson Med 77:774–778, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made.

AbstractBackgroundThe duration of anticytomegalovirus (CMV) prophylaxis after lung transplantation (LT) varies among transplant centers.MethodsA retrospective review of CMV donor‐seropositive/recipient‐seronegative (D+/R−) and CMV recipient‐seropositive (R+) LT patients between January 2005 and September 2012 was performed. Starting January 2007, valganciclovir prophylaxis was given for at least 12 months (often lifelong) for CMV D+/R− and extended from three to six months for R+ LT patients. Risks of CMV infection and CMV disease, and mortality after LT, were assessed.ResultsA total of 88 LT patients were studied, including 32 CMV D+/R−, and 56 R+ patients. During the follow‐up period, 11 (12.5%) patients had asymptomatic CMV infection, and nine (10.3%) developed CMV disease. CMV disease (HR, 4.189; 95% CI: 1.672–10.495; p = 0.002) and CMV infection and disease (HR, 3.775; 95% CI: 1.729–8.240; p = 0.001) were significant risk factors for mortality. Overall, no significant difference was observed in rates of CMV infection or disease among LT recipients who received shorter vs. extended CMV prophylaxis.ConclusionsDespite extended prophylaxis, LT patients remain at risk of CMV infection and disease. CMV remains associated with increased mortality after transplantation.