TY - JOUR
T1 - Primary mitochondrial myopathy
T2 - 12-month follow-up results of an Italian cohort
AU - Montano, V.
AU - Lopriore, P.
AU - Gruosso, F.
AU - Carelli, V.
AU - Comi, G. P.
AU - Filosto, M.
AU - Lamperti, C.
AU - Mongini, T.
AU - Musumeci, O.
AU - Servidei, S.
AU - Tonin, P.
AU - Toscano, A.
AU - Primiano, G.
AU - Valentino, M. L.
AU - Bortolani, S.
AU - Marchet, S.
AU - Ricci, G.
AU - Modenese, A.
AU - Cotti Piccinelli, S.
AU - Risi, B.
AU - Meneri, M.
AU - Arena, I. G.
AU - Siciliano, G.
AU - Mancuso, Michelangelo
N1 - Funding Information:
This work was partially supported by Telethon Grant GUP09004 and Telethon-MITOCON grant GSP16001. CL is partially supported by RF-2016-02361495, MM and CL by EJP RD Joint Transnational Call (JTC2019) GENOMIT.
Funding Information:
Open access funding provided by Università di Pisa within the CRUI-CARE Agreement. We are grateful to the European Reference Network ERN NMD (MM, VM, PL, FG, GS, CL, OM, AT, SS, GP, VC, MLV, TM, MF) and ERN RND (MM, VM, PL, FG, GS) as representatives for the Italian HCP partners.
Publisher Copyright:
© 2022, The Author(s).
PY - 2022/12
Y1 - 2022/12
N2 - Objectives: 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). Methods: 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. Results: 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. Conclusions: 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.
AB - Objectives: 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). Methods: 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. Results: 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. Conclusions: 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.
KW - 6MWT
KW - Fatigue
KW - Mitochondrial disorders
KW - Outcome measures
KW - Pain
KW - Primary mitochondrial myopathy
UR - http://www.scopus.com/inward/record.url?scp=85136109642&partnerID=8YFLogxK
U2 - 10.1007/s00415-022-11324-3
DO - 10.1007/s00415-022-11324-3
M3 - Article
C2 - 35980466
SN - 0340-5354
VL - 269
SP - 6555
EP - 6565
JO - Journal of Neurology
JF - Journal of Neurology
IS - 12
ER -