Table_1_Spatial patterns of white matter hyperintensities: a systematic review.DOCX

BackgroundWhite matter hyperintensities are an important marker of cerebral small vessel disease. This disease burden is commonly described as hyperintense areas in the cerebral white matter, as seen on T2-weighted fluid attenuated inversion recovery magnetic resonance imaging data. Studies have demonstrated associations with various cognitive impairments, neurological diseases, and neuropathologies, as well as clinical and risk factors, such as age, sex, and hypertension. Due to their heterogeneous appearance in location and size, studies have started to investigate spatial distributions and patterns, beyond summarizing this cerebrovascular disease burden in a single metric–its volume. Here, we review the evidence of association of white matter hyperintensity spatial patterns with its risk factors and clinical diagnoses.Design/methodsWe performed a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) Statement. We used the standards for reporting vascular changes on neuroimaging criteria to construct a search string for literature search on PubMed. Studies written in English from the earliest records available until January 31st, 2023, were eligible for inclusion if they reported on spatial patterns of white matter hyperintensities of presumed vascular origin.ResultsA total of 380 studies were identified by the initial literature search, of which 41 studies satisfied the inclusion criteria. These studies included cohorts based on mild cognitive impairment (15/41), Alzheimer’s disease (14/41), Dementia (5/41), Parkinson’s disease (3/41), and subjective cognitive decline (2/41). Additionally, 6 of 41 studies investigated cognitively normal, older cohorts, two of which were population-based, or other clinical findings such as acute ischemic stroke or reduced cardiac output. Cohorts ranged from 32 to 882 patients/participants [median cohort size 191.5 and 51.6% female (range: 17.9–81.3%)]. The studies included in this review have identified spatial heterogeneity of WMHs with various impairments, diseases, and pathologies as well as with sex and (cerebro)vascular risk factors.ConclusionThe results show that studying white matter hyperintensities on a more granular level might give a deeper understanding of the underlying neuropathology and their effects. This motivates further studies examining the spatial patterns of white matter hyperintensities.

背景：白质高信号是脑小血管疾病的重要标志。该疾病负担通常被描述为脑白质中的高信号区域，如T2加权液体衰减反转恢复磁共振成像数据所示。研究表明，其与多种认知障碍、神经系统疾病和神经病理学以及临床和风险因素（如年龄、性别和高血压）存在关联。鉴于其在位置和大小上的异质性，研究已开始探讨其空间分布和模式，而不仅仅是在单一指标——其体积——上概括这一脑血管疾病负担。在此，我们回顾了白质高信号空间模式与其风险因素和临床诊断关联的证据。
方法：我们按照《系统评价和荟萃分析报告规范》（PRISMA）声明进行了系统评价。我们使用神经影像学中血管变化报告标准构建了PubMed文献检索的搜索字符串。如果截至2023年1月31日，研究报告了假设为血管源性白质高信号的空间模式，则这些用英语撰写的最早记录均符合纳入标准。
结果：初步文献检索共确定了380项研究，其中41项研究符合纳入标准。这些研究包括基于轻度认知障碍（15/41）、阿尔茨海默病（14/41）、痴呆（5/41）、帕金森病（3/41）和主观认知下降（2/41）的队列。此外，41项研究中的6项调查了认知正常的老年队列，其中两项为基于人群的研究，或其他临床发现，如急性缺血性卒中或心输出量减少。队列的参与者/患者数量从32到882不等[中位队列大小为191.5，女性比例为51.6%（范围：17.9-81.3%）]。本综述中纳入的研究已确定了白质高信号的空间异质性，以及与各种功能障碍、疾病和病理学以及性别和（脑）血管风险因素的关联。
结论：结果表明，在更精细的层面上研究白质高信号可能对揭示潜在的神经病理学和它们的影响有更深刻的理解。这激励了进一步研究白质高信号的空间模式。