White matter lesions (WMLs) are common in older adults and represent an important predictor of negative long-term outcomes. Rest-activity rhythm disturbance is also common, however, few studies have investigated associations between these factors. We employed a novel AI-based automatic WML segmentation tool and diffusion-weighted tractography to investigate associations between tract specific WML volumes and non-parametric actigraphy measures in older adults at risk for cognitive decline. The primary non-parametric measures of interest were inter-daily stability (IS), intra-daily variability and relative amplitude, with the anterior thalamic radiation (ATR), superior longitudinal fasciculus (SLF) and inferior longitudinal fasciculus (ILF) selected as tracts of interest. One hundred and eight participants at risk for cognitive decline (classified as experiencing subjective or objective cognitive decline) were included (mean age = 68.85 years, SD = 8.91). Of the primary non-parametric measures of interest, results showed that lower IS was associated with a greater likelihood of higher WML burden in the ATR (OR = 1.82, 95% CI [1.12,3.15]). Analysis of secondary non-parametric measures revealed later onset of the least active period to be associated with greater likelihood of high WML burden in the SLF (OR = 1.55, 95% CI [1.00,2.53]) and increased activity during the least active 5-h period to be associated with a greater likelihood of high whole-brain WML burden (OR = 1.83, 95% CI [1.06,3.47]). This study shows integrity of the ATR and SLF, and overall WML burden is linked to altered rest-activity rhythms in older adults at risk for cognitive decline, with those demonstrating altered rest-activity rhythms showing 50%-80% higher odds of having high WML burden.

白质病变 (WML) 在老年人中很常见，是长期负面结果的重要预测指标。休息活动节律紊乱也很常见，但是，很少有研究调查这些因素之间的关联。我们采用了一种新的基于 AI 的自动 WML 分割工具和扩散加权纤维束成像技术，以研究有认知能力下降风险的老年人的纤维束特定 WML 体积与非参数活动记录仪测量之间的关联。感兴趣的主要非参数测量是日间稳定性 (IS)、日内变异性和相对振幅，前丘脑辐射 (ATR)、上纵束 (SLF) 和下纵束 (ILF) 选择为束出于兴趣。包括 108 名有认知能力下降风险的参与者（分类为经历主观或客观认知能力下降）（平均年龄 = 68.85 岁，SD = 8.91）。在感兴趣的主要非参数测量中，结果显示较低的 IS 与 ATR 中较高 WML 负荷的可能性较大相关（OR = 1.82，95% CI [1.12,3.15]）。次要非参数测量分析显示，最不活跃时期的较晚出现与 SLF 中高 WML 负荷的可能性更大（OR = 1.55，95% CI [1.00,2.53]）和最不活跃时期的活动增加相关 5 -h 期与更高的全脑 WML 负荷可能性相关（OR = 1.83, 95% CI [1.06,3.47]）。这项研究显示了 ATR 和 SLF 的完整性，