Background In older adults, elevated gait variability when walking has been associated with both cognitive impairment and future falls. This study leveraged 3 existing data sets to determine relationships between gait variability and the strength of functional connectivity within and between large-scale brain networks in healthy older adults, those with mild-to-moderate functional impairment, and those with Parkinson’s disease (PD). Method Gait and resting-state functional magnetic resonance imaging data were extracted from existing data sets on: (i) 12 older adults without overt disease yet with slow gait and mild executive dysfunction; (ii) 12 older adults with intact cognitive-motor function and age- and sex-matched to the first cohort; and (iii) 15 individuals with PD. Gait variability (%, coefficient of variation of stride time) during preferred walking speed was measured and correlated with the degree of functional connectivity within and between 7 established large-scale functional brain networks. Results Regression models adjusted for age and sex revealed that in each cohort, those with less gait variability exhibited greater negative correlation between fluctuations in resting-state brain activity between the default network and the dorsal attention network (functionally limited older: β = 4.38, p = .027; healthy older: β = 1.66, p = .032; PD: β = 1.65, p = .005). No other within- or between-network connectivity outcomes were consistently related to gait variability across all 3 cohorts. Conclusion These results provide strong evidence that gait variability is uniquely related to functional connectivity between the default network and the dorsal attention network, and that this relationship may be independent of both functional status and underlying brain disease.

中文翻译：

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步态变异性与默认和背侧注意脑网络之间的功能连接强度相关：来自多个队列的证据

背景 在老年人中，行走时步态变异性增加与认知障碍和未来跌倒有关。这项研究利用 3 个现有数据集来确定健康老年人、轻度至中度功能障碍患者和帕金森氏病 (PD) 患者的步态变异与大规模大脑网络内部和之间的功能连接强度之间的关系. 方法 从以下现有数据集中提取步态和静息状态功能磁共振成像数据：(i) 12 名没有明显疾病但步态缓慢和轻度执行功能障碍的老年人；(ii) 12 名具有完整认知运动功能且年龄和性别与第一组相匹配的老年人；(iii) 15 名 PD 患者。步态变异性 (%, 测量了首选步行速度期间的步幅时间变异系数，并将其与 7 个已建立的大规模功能性大脑网络内部和之间的功能连接程度相关联。结果 根据年龄和性别调整的回归模型显示，在每个队列中，步态变异性较小的人在默认网络和背侧注意网络之间的静息状态大脑活动波动之间表现出更大的负相关（功能受限的老年人：β = 4.38，p = .027；健康的老年人：β = 1.66，p = .032；PD：β = 1.65，p = .005）。在所有 3 个队列中，没有其他网络内或网络间连接结果与步态变异性始终相关。