Cavanagh Sarah K, Gochyyev Perman, Nayeem Rashida, Dusang Aliceson N, Hamilton Taya, DiCarlo Julie A, Kautz Steven A, Sternad Dagmar, Walsh Conor, Hochberg Leigh, Lin David J
John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA.
Center for Neurotechnology and Neurorecovery, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
Neurorehabil Neural Repair. 2025 Aug;39(8):639-652. doi: 10.1177/15459683251340916. Epub 2025 May 31.
BackgroundVariability in movement is critical for performance under dynamic conditions. Stroke causes focal injury to the motor system, disrupts voluntary motor control, and leads to less smooth and more variable upper extremity movements. Few studies have characterized trial-by-trial variation in upper extremity movement smoothness and its clinical and neuroanatomic correlates in the first week post-stroke.ObjectiveTo evaluate trial-by-trial variation in upper extremity movement smoothness during planar reaching and relate it to clinical outcomes and neuroanatomical injury after acute stroke.MethodsTwenty-two patients (4.4 ± 1.7 days post-stroke) and 22 able-bodied adults completed a planar center-out reaching task. Smoothness was quantified with spectral arc length (SPARC). Median and interquartile range (IQR, a quantification of trial-by-trial variation) of SPARC values were assessed. Patients completed a clinical assessment battery acutely and at 90 days post-stroke. MRI-derived stroke lesions were analyzed to estimate basal ganglia, motor cortex, and corticospinal tract injury. Intraclass correlation, Spearman's correlation, and multivariate regression evaluated trial-by-trial variation and its relation to clinical assessments, outcomes, and neuroanatomical injury.ResultsPost-stroke reaching was less smooth and more variable (larger IQR) compared to able-bodied adults. Variability in post-stroke smoothness was primarily driven by within-subject, trial-by-trial variation. More variable smoothness, even after controlling for median smoothness, related to worse performance on clinical assessments and 90-day outcomes. More variable smoothness related to greater corticospinal tract injury (ρ = 0.537, = .011), but not to basal ganglia or motor cortex injury.ConclusionTrial-by-trial variation of movement is valuable for understanding sensorimotor control post-stroke and has implications for targeted neurorehabilitation.
背景
运动变异性对于动态条件下的表现至关重要。中风会导致运动系统局灶性损伤，破坏自主运动控制，并导致上肢运动不那么平稳且变异性更大。很少有研究描述中风后第一周上肢运动平稳性的逐次试验变化及其临床和神经解剖学相关性。
目的
评估急性中风后平面伸展过程中上肢运动平稳性的逐次试验变化，并将其与临床结果和神经解剖学损伤相关联。
方法
22名患者（中风后4.4±1.7天）和22名健康成年人完成了平面中心向外伸展任务。用频谱弧长（SPARC）量化平稳性。评估SPARC值的中位数和四分位间距（IQR，逐次试验变化的一种量化）。患者在急性时和中风后90天完成临床评估。分析磁共振成像（MRI）得出的中风病灶，以估计基底神经节、运动皮层和皮质脊髓束损伤。组内相关、Spearman相关和多元回归评估逐次试验变化及其与临床评估、结果和神经解剖学损伤的关系。
结果
与健康成年人相比，中风后伸展的平稳性较差且变异性更大（IQR更大）。中风后平稳性的变异性主要由受试者内部的逐次试验变化驱动。即使在控制了中位数平稳性之后，更具变异性的平稳性与临床评估和90天结果的较差表现相关。更具变异性的平稳性与更大的皮质脊髓束损伤相关（ρ = 0.537，P = 0.011），但与基底神经节或运动皮层损伤无关。
结论
运动的逐次试验变化对于理解中风后的感觉运动控制很有价值，并且对有针对性的神经康复有影响。
