Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke (Québec), Canada.
Groupe de recherche interdisciplinaire sur les maladies neuromusculaires, NeuromuscularClinic, Centre intégré Universitaire de Santé et de Services Sociaux du Saguenay-Lac-St-Jean, site Jonquière, rue de l'Hôpital, Jonquière (Québec), Canada.
J Neuromuscul Dis. 2018;5(2):215-224. doi: 10.3233/JND-170291.
Although adult and late-onset DM1 phenotypes DM1 present distinct lower limb weaknesses portraits, resulting physical limitations have never been described separately for each phenotype.
To characterize the lower limb weaknesses and physical limitations among the DM1 adult and late-onset phenotypes separately and to document the contribution of weaknesses on mobility to optimize the management of this population.
The strength of four muscle groups among 198 participants was quantified. Participants were categorized according to the severity of their muscular involvement using the Muscular Impairment Rating Scale (MIRS). Physical limitations were assessed using the Timed up-and-go (TUG), Berg Balance Scale (BBS) and 10 meters comfortable walking speed (10MWT). Multiple linear regressions were performed to identify the contribution of each muscle group to the mobility tests scores.
Late-onset demonstrated less weakness and physical limitations (p < 0.001 - 0.002) than the adult phenotype, but 21.9-47.5% of participants with this phenotype showed mobility scores below reference values. Physical limitations were observed in the first two MIRS grades (37.5-42.1% of the participants) for the TUG and 10MWT. Ankle dorsiflexors and knee extensors were the two muscle groups that showed the strongest relationships with mobility scores.
Although less impaired, the late-onset phenotype shows significant lower limb muscle weakness associated with physical limitations. The surprising presence of quantitative lower limb muscle weakness in the first two MIRS grades needs to be considered when using this scale. Both ankle dorsiflexors and knee extensors appear to be good indicators of physical limitations in DM1.
尽管成年型和晚发型 DM1 表型的下肢肌无力表现不同，但尚未分别对每种表型的身体限制进行描述。
分别描述 DM1 成年型和晚发型表型的下肢肌无力和身体限制，并记录肌无力对移动能力的影响，以优化该人群的管理。
定量测量 198 名参与者的 4 组肌肉群的力量。根据肌肉损伤严重程度评分量表（MIRS）对参与者进行分类。使用计时起立行走测试（TUG）、伯格平衡量表（BBS）和 10 米舒适行走速度（10MWT）评估身体限制。进行多元线性回归以确定每个肌肉群对移动能力测试得分的贡献。
晚发型比成年型表现出较轻的肌无力和身体限制（p < 0.001-0.002），但 21.9-47.5%的该表型参与者的移动能力评分低于参考值。在 TUG 和 10MWT 中，第一和第二 MIRS 等级（37.5-42.1%的参与者）观察到身体限制。踝关节背屈肌和膝关节伸肌是与移动能力评分相关性最强的两个肌肉群。
尽管受影响较小，晚发型表型仍表现出明显的下肢肌无力，伴有身体限制。在使用这种量表时，需要考虑到前两个 MIRS 等级中存在定量的下肢肌肉无力。踝关节背屈肌和膝关节伸肌似乎是 DM1 中身体限制的良好指标。
