Beheshti Iman, Potvin Olivier, Dadar Mahsa, Duchesne Simon
Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada.
Centre de recherche CERVO, Québec, QC, Canada.
Front Dement. 2024 Jun 21;3:1380015. doi: 10.3389/frdem.2024.1380015. eCollection 2024.
White matter hyperintensities (WMHs) and cerebral microbleeds are widespread among aging population and linked with cognitive deficits in mild cognitive impairment (MCI), vascular MCI (V-MCI), and Alzheimer's disease without (AD) or with a vascular component (V-AD). In this study, we aimed to investigate the association between brain age, which reflects global brain health, and cerebrovascular lesion load in the context of pathological aging in diverse forms of clinically-defined neurodegenerative conditions.
We computed brain-predicted age difference (brain-PAD: predicted brain age minus chronological age) in the Comprehensive Assessment of Neurodegeneration and Dementia cohort of the Canadian Consortium on Neurodegeneration in Aging including 70 cognitively intact elderly (CIE), 173 MCI, 88 V-MCI, 50 AD, and 47 V-AD using T1-weighted magnetic resonance imaging (MRI) scans. We used a well-established automated methodology that leveraged fluid attenuated inversion recovery MRIs for precise quantification of WMH burden. Additionally, cerebral microbleeds were detected utilizing a validated segmentation tool based on the ResNet50 network, utilizing routine T1-weighted, T2-weighted, and T2 MRI scans.
The mean brain-PAD in the CIE cohort was around zero, whereas the four categories showed a significantly higher mean brain-PAD compared to CIE, except MCI group. A notable association trend between brain-PAD and WMH loads was observed in aging and across the spectrum of cognitive impairment due to AD, but not between brain-PAD and microbleed loads.
WMHs were associated with faster brain aging and should be considered as a risk factor which imperils brain health in aging and exacerbate brain abnormalities in the context of neurodegeneration of presumed AD origin. Our findings underscore the significance of novel research endeavors aimed at elucidating the etiology, prevention, and treatment of WMH in the area of brain aging.
脑白质高信号（WMHs）和脑微出血在老年人群中普遍存在，并与轻度认知障碍（MCI）、血管性MCI（V-MCI）以及无血管成分或有血管成分的阿尔茨海默病（AD）中的认知缺陷相关。在本研究中，我们旨在探讨反映整体脑健康的脑龄与不同形式临床定义的神经退行性疾病病理衰老背景下脑血管病变负荷之间的关联。
我们在加拿大衰老神经退行性疾病联盟的神经退行性变和痴呆综合评估队列中，使用T1加权磁共振成像（MRI）扫描计算脑预测年龄差（脑-PAD：预测脑龄减去实际年龄），该队列包括70名认知正常的老年人（CIE）、173名MCI患者、88名V-MCI患者、50名AD患者和47名V-AD患者。我们使用一种成熟的自动化方法，该方法利用液体衰减反转恢复MRI精确量化WMH负担。此外，利用基于ResNet50网络的经过验证的分割工具，通过常规T1加权、T2加权和T2* MRI扫描检测脑微出血。
CIE队列中的平均脑-PAD约为零，而除MCI组外，其他四类的平均脑-PAD均显著高于CIE。在衰老过程中以及整个AD所致认知障碍范围内，观察到脑-PAD与WMH负荷之间存在显著的关联趋势，但脑-PAD与微出血负荷之间未观察到这种关联。
WMHs与脑衰老加快相关，应被视为一种危险因素，它危害衰老过程中的脑健康，并在假定源于AD的神经退行性变背景下加剧脑异常。我们的研究结果强调了旨在阐明脑衰老领域中WMHs的病因、预防和治疗的新研究工作的重要性。
