Department of Neurology, University of Pittsburgh Medical Center, 811 Kaufmann Medical Building, 3471 Fifth Avenue, Pittsburgh, PA, 15213, USA.
Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA, USA.
Aging Clin Exp Res. 2019 May;31(5):611-619. doi: 10.1007/s40520-018-1028-4. Epub 2018 Aug 28.
In older adults, impaired postural control contributes to falls, a major source of morbidity. Understanding central mechanisms may help identify individuals at risk for impaired postural control.
To determine the relationship between gray matter volume (GMV), white matter hyperintensities (WMH), mean diffusivity (MD), and fractional anisotropy (FA) with lateral postural control.
Neuroimaging and postural control were assessed in 193 community-dwelling older adults (mean age 82, 55.4% female, 44.6% black). GMV, WMH, and diffusion tensor-derived markers of microstructure (MD and FA) were quantified for total brain and regions of interest. Lateral postural control was defined as the root mean square error (RMSE) of lateral sway during a visual feedback test. Associations were assessed with linear regression, adjusted for total brain atrophy and risk factors for impaired postural control.
RMSE was higher for women than men (p < 0.001) and inversely correlated with gait speed (r = - 0.20, p = 0.01), modified mini-mental state (r = - 0.27, p < 0.001), digit symbol substitution test (r = - 0.20, p = 0.01) and quadriceps strength (r = - 0.18, p = 0.01). RMSE was inversely associated with GMV of bilateral precuneus (r = - 0.26, p = 0.01) and FA of corpus callosum and selected tracts in the right hemisphere (anterior thalamic radiation, cingulum, inferior longitudinal and fronto-occipital fasciculi), independent of covariates (r = - 0.34 to - 0.18, p ≤ 0.04).
Lower GMV and microstructural white matter integrity in selected networks can explain worse lateral postural control in older ambulatory adults without neurologic diseases.
Neuroimaging markers of poor postural control in healthy aging may help identify increased fall risk and design preventative fall strategies.
在老年人中，姿势控制能力受损是导致跌倒的主要原因之一，跌倒也是发病率的主要来源。了解中枢机制可能有助于确定姿势控制能力受损的风险人群。
确定灰质体积（GMV）、白质高信号（WMH）、平均扩散系数（MD）和各向异性分数（FA）与侧方姿势控制之间的关系。
对 193 名居住在社区的老年人（平均年龄 82 岁，55.4%为女性，44.6%为黑人）进行神经影像学和姿势控制评估。对全脑和感兴趣区的 GMV、WMH 和弥散张量衍生的微观结构标志物（MD 和 FA）进行量化。侧方姿势控制定义为视觉反馈测试中侧向摆动的均方根误差（RMSE）。使用线性回归评估关联，调整全脑萎缩和影响姿势控制的危险因素。
女性的 RMSE 高于男性（p<0.001），与步态速度（r=-0.20，p=0.01）、改良 mini-mental 状态（r=-0.27，p<0.001）、数字符号替代测试（r=-0.20，p=0.01）和股四头肌力量（r=-0.18，p=0.01）呈负相关。RMSE 与双侧楔前叶 GMV 呈负相关（r=-0.26，p=0.01），与胼胝体和右侧半球的选定束 FA 呈负相关（前丘脑辐射、扣带、下纵束和额枕束），独立于协变量（r=-0.34 至-0.18，p≤0.04）。
在无神经疾病的老年活动成年人中，特定网络中 GMV 降低和微观结构白质完整性降低可解释其侧方姿势控制能力较差。
健康老年人姿势控制不良的神经影像学标志物可能有助于识别更高的跌倒风险，并制定预防跌倒的策略。
