Analysis of the functional capacity outcome measures for myotonic dystrophy

Abstract

Objectives Defining clinically relevant outcome measures for myotonic dystrophy type 1 (DM1) that can be valid and feasible for different phenotypes has proven problematic. The Outcome Measures for Myotonic Dystrophy (OMMYD) group proposed a battery of functional outcomes: 6‐minute walk test, 30 seconds sit and stand test, timed 10 m walk test, timed 10 m walk/run test, and nine‐hole peg test. This, however, required a large‐scale investigation, Methods A cohort of 213 patients enrolled in the natural history study, PhenoDM1, was analyzed in cross‐sectional analysis and subsequently 98 patients were followed for longitudinal analysis. We aimed to assess: (1) feasibility and best practice; (2) intra‐session reliability; (3) validity; and (4) behavior over time, of these tests. Results OMMYD outcomes proved feasible as 96% of the participants completed at least one trial for all tests and more than half (n = 113) performed all three trials of each test. Body mass index and disease severity associate with functional capacity. There was a significant difference between the first and second trials of each test. There was a moderate to strong correlation between these functional outcomes and muscle strength, disease severity and patient‐reported outcomes. All outcomes after 1 year detected a change in functional capacity except the nine‐hole peg test. Conclusions These tests can be used as a battery of outcomes or independently based on the shown overlapping psychometric features and strong cross‐correlations. Due to the large and heterogeneous sample of this study, these results can serve as reference values for future studies.

Clearance of defective muscle stem cells by senolytics reduces the expression of senescence-associated secretory phenotype and restores myogenesis in myotonic dystrophy type 1

“…Muscle strength was expressed as the expected muscle strength of healthy individuals based on a French isometric strength normative database using predictive equations taking into consideration age, sex, and weight of the patients 31 . Patients were subjected to a battery of validated functional tests 63, 64 . Timed-up and Go: time to stand up, walk three meters, turn and walk back to sit down on the chair; 10mWT: comfortable walking speed (m/s) along a 10-meter distance; Berg balance scale: 14 items measuring static and dynamic balance (maximum score of 56 indicating no deficit in balance); Pinch strength: measured using a B&L pinch gauge (kg).…”

Responsiveness of outcome measures in myotonic dystrophy type 1

“…None of the functional mobility tests in this study showed change in 1 year, which is at variance with other studies in DM1 using these tests. 9,18 The discrepancies may be due to differences in test methods, 9,18 unspecified DM-type, 18 and a larger sample size. 9 Changes in the 10mWT after a longer period of time has previously been shown in DM1.…”

“…4 Only the 30-second sit-to-stand test (STS) and 10-meter walk test (10mWT, walk/run max pace) have been investigated after 1 year. 9 Responsiveness of commonly used endpoints such as stationary dynamometry, step test, feet-together stance, tandem stance, one-leg stance, modified clinical test of sensory integration and balance (mCTSIB), 10mWT (walk, fast pace), and 10-times STS in DM1 is still unknown.…”

Pruebas cronometradas en pacientes deambuladores con enfermedades neuromusculares

“…5,6 Los cambios esperables en el tiempo por progresión de la debilidad muscular en diferentes enfermedades, han sido reportados. 4,[7][8][9][10][11][12][13][14][15] Además, estas pruebas se han utilizado como variable de resultado para medir eficacia en diferentes protocolos de investigación. [16][17][18][19][20][21] El objetivo de este trabajo es describir las cuatro pruebas cronometradas más comúnmente utilizadas para evaluar a los pacientes deambuladores con enfermedades neuromusculares: pararse desde supino, marcha o carrera de 10 metros y subir y bajar 4 escalones.…”