Department of Clinical and Experimental Medicine, Neurological Clinic, University of Pisa, Pisa, Italy.
IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy.
J Neurol. 2022 Dec;269(12):6555-6565. doi: 10.1007/s00415-022-11324-3. Epub 2022 Aug 18.
To assess natural history and 12-month change of a series of scales and functional outcome measures in a cohort of 117 patients with primary mitochondrial myopathy (PMM).
Twelve months follow-up data of 117 patients with PMM were collected. We analysed the 6-min walk test (6MWT), timed up-and-go test (× 3) (3TUG), five-times sit-to-stand test (5XSST), timed water swallow test (TWST), and test of masticating and swallowing solids (TOMASS) as functional outcome measures; the Fatigue Severity Scale and West Haven-Yale Multidimensional pain inventory as patient-reported outcome measures. PMM patients were divided into three phenotypic categories: mitochondrial myopathy (MiMy) without extraocular muscles involvement, pure chronic progressive external ophthalmoplegia (PEO) and PEO&MiMy. As 6MWT is recognized to have significant test-retest variability, we calculated MCID (minimal clinically important difference) as one third of baseline 6 min walking distance (6MWD) standard deviation.
At 12-month follow-up, 3TUG, 5XSST and FSS were stable, while TWST and the perceived pain severity (WHYMPI) worsened. 6MWD significantly increased in the entire cohort, especially in the higher percentiles and in PEO patients, while was substantially stable in the lower percentile (< 408 m) and MiMy patients. This increase in 6MWD was considered not significant, as inferior to MCID (33.3 m). NMDAS total score showed a slight but significant decline at 12 months (0.9 point). The perceived pain severity significantly worsened. Patients with PEO performed better in functional measures than patients with PEO&MiMy or MiMy, and had lower values of NMDAS.
PMM patients showed a slow global decline valued by NMDAS at 12 months; 6MWT was a more reliable measurement below 408 m, substantially stable at 12 months. PEO patients had better motor performance and lower NMDAS than PEO&MiMy and MiMy also at 12 months of follow-up.
评估原发性线粒体肌病（PMM）患者队列中一系列量表和功能结果测量的自然史和 12 个月变化。
收集 117 例 PMM 患者的 12 个月随访数据。我们分析了 6 分钟步行测试（6MWT）、3 次起立-行走测试（3TUG）、5 次坐-站测试（5XSST）、定时饮水吞咽测试（TWST）和咀嚼吞咽固体测试（TOMASS）作为功能结果测量；疲劳严重程度量表和惠顿-耶鲁多维疼痛量表作为患者报告的结果测量。PMM 患者分为三种表型类别：无眼外肌受累的线粒体肌病（MiMy）、单纯慢性进行性眼外肌麻痹（PEO）和 PEO&MiMy。由于 6MWT 具有显著的测试-重测变异性，我们计算了 MCID（最小临床重要差异）作为基线 6 分钟步行距离（6MWD）标准差的三分之一。
在 12 个月随访时，3TUG、5XSST 和 FSS 保持稳定，而 TWST 和感知疼痛严重程度（WHYMPI）恶化。整个队列的 6MWD 显著增加，尤其是在较高百分位数和 PEO 患者中，而在较低百分位数（<408m）和 MiMy 患者中则基本稳定。6MWD 的这种增加被认为不显著，低于 MCID（33.3m）。NMDAS 总分在 12 个月时略有但显著下降（0.9 分）。感知疼痛严重程度显著恶化。PEO 患者在功能测量中表现优于 PEO&MiMy 或 MiMy 患者，且 NMDAS 值较低。
PMM 患者在 12 个月时表现出 NMDAS 评估的缓慢全面下降；6MWT 在 408m 以下是一种更可靠的测量方法，在 12 个月时基本稳定。PEO 患者在 12 个月随访时的运动表现优于 PEO&MiMy 和 MiMy，且 NMDAS 较低。
