Carlson Sarah J, Chiu Yi-Fang, Landers Merrill R, Fritz Nora E, Mishra Virendra R, Longhurst Jason K
Department of Physical Therapy and Athletic Training, Saint Louis University, St. Louis, Missouri, USA,
Department of Speech, Language, and Hearing Sciences, Saint Louis University, St. Louis, Missouri, USA.
Neurodegener Dis. 2024;24(3-4):106-116. doi: 10.1159/000540393. Epub 2024 Jul 31.
Parkinson's disease (PD) reduces an individual's capacity for automaticity which limits their ability to perform two tasks simultaneously, negatively impacting daily function. Understanding the neural correlates of dual tasks (DTs) may pave the way for targeted therapies. To better understand automaticity in PD, we aimed to explore whether individuals with differing DT performances possessed differences in brain morphologic characteristics.
Data were obtained from 34 individuals with PD and 47 healthy older adults including (1) demographics (age, sex), (2) disease severity (Movement Disorder Society - Unified Parkinson's Disease Rating Scale [MDS-UPDRS], Hoehn and Yahr, levodopa equivalent daily dose [LEDD]), (3) cognition (Montreal Cognitive Assessment), (4) LEDD, (5) single-task and DT performance during a DT-timed-up-and-go test utilizing a serial subtraction task, and (6) cortical thicknesses and subcortical volumes obtained from volumetric MRI. Participants were categorized as low or high DT performers if their combined DT effect was greater than the previously determined mean value for healthy older adults (μ = -74.2). Nonparametric testing using Quade's ANCOVA was conducted to compare cortical thicknesses and brain volumes between the highDT and lowDT groups while controlling for covariates: age, sex, MDS-UPDRS part III, LEDD, and intracranial volume. Secondarily, similar comparisons were made between the healthy older adult group and the highDT and lowDT groups. Lastly, a hierarchical linear regression model was conducted regressing combined DT effect on covariates (block one) and cortical thicknesses (block 2) in stepwise fashion.
The highDT group had thicker cortices than the lowDT group in the right primary somatosensory cortex (p = 0.001), bilateral primary motor cortices (p ≤ 0.001, left; p = 0.002, right), bilateral supplementary motor areas (p = 0.001, left; p < 0.001, right), and mean of the bilateral hemispheres (p = 0.001, left; p < 0.001, right). Of note, left primary cortex thickness (p = 0.002), left prefrontal cortex thickness (p < 0.001), and right supplementary motor area thickness (p = 0.003) differed when adding a healthy comparison group. Additionally, the regression analysis found that the left paracentral lobule thickness explained 20.8% of the variability in combined DT effect (p = 0.011) beyond the influence of covariates.
These results suggest regions underlying DT performance, specifically, a convergence of neural control relying on sensorimotor integration, motor planning, and motor activation to achieve higher levels of DT performance for individuals with PD.
Parkinson's disease (PD) reduces an individual's capacity for automaticity which limits their ability to perform two tasks simultaneously, negatively impacting daily function. Understanding the neural correlates of dual tasks (DTs) may pave the way for targeted therapies. To better understand automaticity in PD, we aimed to explore whether individuals with differing DT performances possessed differences in brain morphologic characteristics.
Data were obtained from 34 individuals with PD and 47 healthy older adults including (1) demographics (age, sex), (2) disease severity (Movement Disorder Society - Unified Parkinson's Disease Rating Scale [MDS-UPDRS], Hoehn and Yahr, levodopa equivalent daily dose [LEDD]), (3) cognition (Montreal Cognitive Assessment), (4) LEDD, (5) single-task and DT performance during a DT-timed-up-and-go test utilizing a serial subtraction task, and (6) cortical thicknesses and subcortical volumes obtained from volumetric MRI. Participants were categorized as low or high DT performers if their combined DT effect was greater than the previously determined mean value for healthy older adults (μ = -74.2). Nonparametric testing using Quade's ANCOVA was conducted to compare cortical thicknesses and brain volumes between the highDT and lowDT groups while controlling for covariates: age, sex, MDS-UPDRS part III, LEDD, and intracranial volume. Secondarily, similar comparisons were made between the healthy older adult group and the highDT and lowDT groups. Lastly, a hierarchical linear regression model was conducted regressing combined DT effect on covariates (block one) and cortical thicknesses (block 2) in stepwise fashion.
The highDT group had thicker cortices than the lowDT group in the right primary somatosensory cortex (p = 0.001), bilateral primary motor cortices (p ≤ 0.001, left; p = 0.002, right), bilateral supplementary motor areas (p = 0.001, left; p < 0.001, right), and mean of the bilateral hemispheres (p = 0.001, left; p < 0.001, right). Of note, left primary cortex thickness (p = 0.002), left prefrontal cortex thickness (p < 0.001), and right supplementary motor area thickness (p = 0.003) differed when adding a healthy comparison group. Additionally, the regression analysis found that the left paracentral lobule thickness explained 20.8% of the variability in combined DT effect (p = 0.011) beyond the influence of covariates.
These results suggest regions underlying DT performance, specifically, a convergence of neural control relying on sensorimotor integration, motor planning, and motor activation to achieve higher levels of DT performance for individuals with PD.
帕金森病（PD）会降低个体的自动性能力，这限制了他们同时执行两项任务的能力，对日常功能产生负面影响。了解双重任务（DT）的神经关联可能为靶向治疗铺平道路。为了更好地理解帕金森病中的自动性，我们旨在探讨不同DT表现的个体在脑形态特征上是否存在差异。
数据来自34名帕金森病患者和47名健康老年人，包括（1）人口统计学信息（年龄、性别），（2）疾病严重程度（运动障碍协会统一帕金森病评定量表[MDS-UPDRS]、 Hoehn和Yahr分期、左旋多巴等效日剂量[LEDD]），（3）认知功能（蒙特利尔认知评估），（4）LEDD，（5）在使用连续减法任务的DT计时起立行走测试中的单任务和DT表现，以及（6）从容积性MRI获得的皮质厚度和皮质下体积。如果参与者的DT综合效应大于先前确定的健康老年人平均值（μ = -74.2），则将其分类为低DT表现者或高DT表现者。使用Quade方差分析进行非参数检验，以比较高DT组和低DT组之间的皮质厚度和脑体积，同时控制协变量：年龄、性别、MDS-UPDRS第三部分、LEDD和颅内体积。其次，在健康老年人群体与高DT组和低DT组之间进行了类似的比较。最后，进行了分层线性回归模型，以逐步方式将DT综合效应回归到协变量（第一组）和皮质厚度（第二组）上。
高DT组在右侧初级体感皮层（p = 0.001）、双侧初级运动皮层（左侧p ≤ 0.001；右侧p = 0.002）、双侧辅助运动区（左侧p = 0.001；右侧p < 0.001）以及双侧半球平均值（左侧p = 0.001；右侧p < 0.001）的皮质比低DT组更厚。值得注意的是，加入健康对照组后，左侧初级皮层厚度（p = 0.002）、左侧前额叶皮层厚度（p < 0.001）和右侧辅助运动区厚度（p = 0.003）存在差异。此外，回归分析发现，在协变量的影响之外，左侧中央旁小叶厚度解释了DT综合效应变异性的20.8%（p = 0.011）。
这些结果表明了DT表现背后的区域，具体而言，是一种神经控制的汇聚，依赖于感觉运动整合（sensorimotor integration）、运动规划和运动激活，以实现帕金森病患者更高水平的DT表现。
帕金森病（PD）会降低个体的自动性能力，这限制了他们同时执行两项任务的能力，对日常功能产生负面影响。了解双重任务（DT）的神经关联可能为靶向治疗铺平道路。为了更好地理解帕金森病中的自动性，我们旨在探讨不同DT表现的个体在脑形态特征上是否存在差异。
数据来自34名帕金森病患者和47名健康老年人，包括（1）人口统计学信息（年龄、性别），（2）疾病严重程度（运动障碍协会统一帕金森病评定量表[MDS-UPDRS]、 Hoehn和Yahr分期、左旋多巴等效日剂量[LEDD]），（3）认知功能（蒙特利尔认知评估），（4）LEDD，（5）在使用连续减法任务的DT计时起立行走测试中的单任务和DT表现，以及（6）从容积性MRI获得的皮质厚度和皮质下体积。如果参与者的DT综合效应大于先前确定的健康老年人平均值（μ = -74.2），则将其分类为低DT表现者或高DT表现者。使用Quade方差分析进行非参数检验，以比较高DT组和低DT组之间的皮质厚度和脑体积，同时控制协变量：年龄、性别、MDS-UPDRS第三部分、LEDD和颅内体积。其次，在健康老年人群体与高DT组和低DT组之间进行了类似的比较。最后，进行了分层线性回归模型，以逐步方式将DT综合效应回归到协变量（第一组）和皮质厚度（第二组）上。
高DT组在右侧初级体感皮层（p = 0.001）、双侧初级运动皮层（左侧p ≤ 0.001；右侧p = 0.002）、双侧辅助运动区（左侧p = 0.001；右侧p < 0.001）以及双侧半球平均值（左侧p = 0.001；右侧p < 0.001）的皮质比低DT组更厚。值得注意的是，加入健康对照组后，左侧初级皮层厚度（p = 0.002）、左侧前额叶皮层厚度（p < 0.001）和右侧辅助运动区厚度（p = 0.003）存在差异。此外，回归分析发现，在协变量的影响之外，左侧中央旁小叶厚度解释了DT综合效应变异性的20.8%（p = 0.011）。
这些结果表明了DT表现背后的区域，具体而言，是一种神经控制的汇聚，依赖于感觉运动整合（sensorimotor integration）、运动规划和运动激活，以实现帕金森病患者更高水平的DT表现。
