BACKGROUND Hand-motor impairment affects a large proportion of multiple sclerosis (MS) patients; however, its substrates are still poorly understood. OBJECTIVES To investigate the association between global disability, hand-motor impairment, and alterations in motor-relevant structural and functional magnetic resonance imaging (MRI) networks in MS patients with different clinical phenotypes. METHODS One hundred thirty-four healthy controls (HC) and 364 MS patients (250 relapsing-remitting MS (RRMS) and 114 progressive MS (PMS)) underwent Expanded Disability Status Scale (EDSS) rating, nine-hole peg test (9HPT), and electronic finger tapping rate (EFTR). Structural and resting state (RS) functional MRI scans were used to perform a source-based morphometry on gray matter (GM) components, to analyze white matter (WM) tract diffusivity indices and to perform a RS seed-based approach from the primary motor cortex involved in hand movement (hand-motor cortex). Random forest analyses identified the predictors of clinical impairment. RESULT In RRMS, global measures of atrophy and lesions together with measures of structural damage of motor-related regions predicted EDSS (out-of-bag (OOB)-R2 = 0.19, p-range = <0.001-0.04), z9HPT (right: OOB-R2 = 0.14; left: OOB-R2 = 0.24, p-range = <0.001-0.03). No RS functional connectivity (FC) abnormalities were identified in RRMS models. In PMS, cerebellar and sensorimotor regions atrophy, cerebellar peduncles integrity and increased RS FC between left hand-motor cortex and right inferior frontal gyrus predicted EDSS (OBB-R2 = 0.16, p-range = 0.02-0.04). CONCLUSION In RRMS, only measures of structural damage contribute to explain motor impairment, whereas both structural and functional MRI measures predict clinical disability in PMS. A multiparametric MRI approach could be relevant to investigate hand-motor impairment in different MS phenotypes.

中文翻译：

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MRI 与多发性硬化表型临床残疾和手部运动能力的相关性

背景手部运动障碍影响很大比例的多发性硬化症 (MS) 患者。然而，它的底物仍然知之甚少。目的 调查具有不同临床表型的 MS 患者全身残疾、手部运动障碍以及运动相关结构和功能磁共振成像 (MRI) 网络改变之间的关联。方法 134 名健康对照 (HC) 和 364 名 MS 患者（250 名复发缓解型 MS (RRMS) 和 114 名进行性多发性硬化症 (PMS)）接受了扩展残疾状态量表 (EDSS) 评级、九孔钉测试 (9HPT) ，以及电子手指敲击率 (EFTR)。结构和静息状态 (RS) 功能 MRI 扫描用于对灰质 (GM) 成分进行基于源的形态测量，分析白质 (WM) 束扩散指数，并从参与手部运动的初级运动皮层（手运动皮层）执行基于 RS 种子的方法。随机森林分析确定了临床损伤的预测因素。结果在 RRMS 中，萎缩和病变的整体测量值以及运动相关区域结构损伤的测量值预测了 EDSS（袋外 (OOB)-R2 = 0.19，p 范围 = <0.001-0.04），z9HPT（右：OOB-R2 = 0.14；左图：OOB-R2 = 0.24，p 范围 = <0.001-0.03）。在 RRMS 模型中未发现 RS 功能连接 (FC) 异常。在 PMS 中，小脑和感觉运动区域萎缩，小脑脚的完整性和左手运动皮层和右额下回之间的 RS FC 增加预测了 EDSS（OBB-R2 = 0.16，p 范围 = 0.02-0.04）。结论 在 RRMS 中，只有结构损伤的测量有助于解释运动障碍，而结构和功能 MRI 测量都预测 PMS 的临床残疾。多参数 MRI 方法可能与调查不同 MS 表型的手部运动障碍有关。