Background Recovery of upper extremity (UE) motor function after stroke is variable from one to another due to heterogeneity of stroke pathology. Structural and biochemical magnetic resonance imaging of the primary motor cortex (M1) have been used to document reorganization of neural activity after stroke. Objective To assess cortical biochemical and structural causes of delayed recovery of UE motor function impairment in chronic subcortical ischemic stroke patients. Methodology A cross-sectional study with fifty patients were enrolled: thirty patients with chronic (> 6 months) subcortical ischemic stroke suffering from persistent UE motor function impairment (not improved group) and twenty patients with chronic subcortical ischemic stroke and improved UE motor function (improved group). We recruited a group of (16) age-matched healthy subjects. Single voxel proton magnetic resonance spectroscopy (1H-MRS) was performed to measure n -acetylaspartate (NAA) and glutamate+glutamine (Glx) ratios relative to creatine (Cr) in the precentral gyrus which represent M1of hand area in both ipsilesional and contralesional hemispheres. Brain magnetic resonance imaging (MRI) to measure precentral gyral thickness is representing the M1of hand area. UE motor function assessment is using the Fugl Meyer Assessment (FMA-UE) Scale. Results The current study found that ipslesional cortical thickness was significantly lower than contralesional cortical thickness among all stroke patients. Our study found that ipsilesional NAA/Cr ratio was lower than contralesional NAA/Cr among stroke patients. UE and hand motor function by FMA-UE showed highly statistically significant correlation with ipsilesional cortical thickness and ipsilesional NAA/Cr ratio, more powerful with NAA/Cr ratio. Conclusion We concluded that persistent motor impairment in individuals with chronic subcortical stroke may be at least in part related to ipsilesional structural and biochemical changes in motor areas remote from infarction in form of decreased cortical thickness and NAA/Cr ratio which had the strongest relationship with that impairment.

中文翻译：

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慢性脑卒中生化和结构磁共振成像与上肢运动功能的关系

背景 由于中风病理的异质性，中风后上肢 (UE) 运动功能的恢复因人而异。初级运动皮层 (M1) 的结构和生化磁共振成像已被用于记录中风后神经活动的重组。目的 评估慢性皮层下缺血性卒中患者 UE 运动功能障碍恢复延迟的皮层生化和结构原因。方法 纳入 50 名患者的横断面研究：30 名患有持续性 UE 运动功能障碍的慢性（> 6 个月）皮质下缺血性卒中患者（未改善组）和 20 名慢性皮质下缺血性卒中患者和改善 UE 运动功能（改进组）。我们招募了一组 (16) 年龄匹配的健康受试者。进行单体素质子磁共振波谱 (1H-MRS) 以测量中央前回中 n-乙酰天冬氨酸 (NAA) 和谷氨酸 + 谷氨酰胺 (Glx) 相对于肌酸 (Cr) 的比率，代表同侧和对侧半球手部区域的 M1 . 用于测量中央前回厚度的脑磁共振成像 (MRI) 代表手部区域的 M1。UE 运动功能评估使用 Fugl Meyer 评估 (FMA-UE) 量表。结果 本研究发现，所有脑卒中患者患侧皮层厚度均显着低于对侧皮层厚度。我们的研究发现，卒中患者同侧 NAA/Cr 比值低于对侧 NAA/Cr。FMA-UE 的 UE 和手部运动功能与同侧皮质厚度和同侧 NAA/Cr 比值具有高度的统计学显着相关性，与 NAA/Cr 比值的相关性更强。结论 我们得出结论，慢性皮层下卒中个体的持续运动障碍可能至少部分与远离梗死的运动区域的同侧结构和生化变化有关，表现为皮质厚度和 NAA/Cr 比值降低，与此相关性最强。减值。