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M.P.3.01 Gait steadiness and upper-body kinematics in DMD children
Abstracts / Neuromuscular Disorders 19 (2009) 543–660
FUNCTIONAL MUSCLE PRESENTATIONS
TESTING
AND
MYOMETRY;
POSTER
M.P.3.01 Gait steadiness and upper-body kinematics in DMD children R. Ganea 1, N. Goemans 2, M. van den Hauwe 2, K. Aminian 1, A. Paraschiv-Ionescu 1, P.Y. Jeannet3 1 Laboratory of Movement Analysis and Measurement, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, 2 Neuromuscular Center & Department of Child Neurology, Universitair Ziekenhuis Gasthuisberg, Leuven, Belgium, 3 Pediatric Neuromuscular Center, Department of Pediatrics, CHUV, Pediatrics, Lausanne, Switzerland
New tools that better assess life-limiting-events in neuromuscular disorders are needed as outcome measures in clinical trials. Quantitative assessment of movement patterns during walking in DMD patients is potentially an objective evaluation of disease severity. While lower limbs initiate and sustain locomotion, motion of the trunk is important for maintaining balance and may be characterized by a dynamic pattern that change with disease progression. Method: The gait pattern of 21 DMD children (age = 8.5 ± 1.7) and 17 agematched healthy controls was analyzed during free walking over 200 m with one gyroscope on each leg and a 3D kinematical sensor (accelerometers and gyroscopes) on the trunk. Gait steadiness (an indicator of compensatory adaptation to the motor deficit) was quantified from (1) the range and step-to-step variability of trunk angular velocity norm (R-AVe), also quantified by median absolute deviation (MAD-AVe) and (2) the smoothness of trunk acceleration norm quantified by spectral entropy (SE-Acc). The MFM scale was used to assess disease severity. Results: The values of R-AVe, MADAVe and SE-Acc were significantly greater in DMD patients (62 ± 9°/s, 11.4 ± 3.7°/s, 0.75 ± 0.06, respectively) compared to healthy control (49.4 ± 7.4°/s, 8.2 ± 1.8°/s, 0.6 ± 0.07), independently of the walking speed which was lower in DMD (0.9 ± 0.17 m/s) compared to control (1.13 ± 0.12 m/s). Higher values were found in more severely affected patients. Discussion: This study shows that upperbody compensatory movement to maintain dynamic balance in DMD patients can be quantified during free-walking over 200 m. These in-lab validated parameters will allow the quantification of walking patterns recorded under long-term daily-life conditions while wearing a single kinematical sensor on the trunk. We hypothesize that the development of such new assessment parameters during gait may allow a better definition and quantification of functional limitation in neuromuscular disorders. doi:10.1016/j.nmd.2009.06.182
M.P.3.02 Detailed analysis of daily-life physical activity patterns in DMD children P.Y. Jeannet1, R. Ganea 2, C. Piot 1, N. Goemans 3, M. van den Hauwe 3, K. Aminian 2, A. Paraschiv-Ionescu 2 1
Pediatric Neuromuscular Center, Department of Pediatrics, CHUV, Lausanne, Switzerland, 2 Laboratory of Movement Analysis and Measurement, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, 3 Neuromuscular Center & Department of Child Neurology, Universitair Ziekenhuis Gasthuisberg, Leuven, Belgium Activity monitors are now used as outcome measures in neuromuscular disorders, but they often monitor limited aspects of physical activity. The aim of this study was to provide a detailed analysis of daily-life physical activity (PA). In 20 ambulatory DMD boys, age 8.5 ± 1.7 y and 18 age-matched healthy controls age
601
8.3 ± 2.2 y. PA was monitored during 3 consecutive days, using a chest worn data-logger (PhysilogÒ) with a 3D inertial sensor (accelerometers and gyroscopes). Body posture and walking parameters were quantified. Gait smoothness was also assessed through quantification of spectral entropy of trunk acceleration pattern. The MFM scale was used to assess disease severity. Results: Time (in %) spent standing and walking in DMD vs. controls was 47.27 ± 9.48, 14.12 ± 5.13 vs. 55.12 ± 9.79, 19.40 ± 5.45. Time (in %) spent sitting and lying in DMD (45.4 ± 8.04, 7.31 ± 5.10) was increased compared to controls (38.91 ± 7.4, 5.95 ± 5.5). The number of walking episodes longer than 1 min and longer than 6 min were decreased compared to controls (7.61 ± 4.7, 0.11 ± 0.26 vs. 11.58 ± 6.5, 0.4 ± 0.6), the same was true for the maximum continuous walking duration and the maximum cadence, (217.39 ± 115.82, 180.27 ± 5.48 vs. 371.86 ± 211.56, 181.88 ± 3.34). Gait pattern was smoother in controls than in DMD (0.71 ± 0.08 vs. 0.61 ± 0.01). There was an overall significant correlation (p < 0.05) between the MFM scores and time spent walking, r = 0.48, number of walking episodes longer than 1 min, r = 0.5 and maximum cadence, r = 0.71. Discussion: This study shows that the type, duration, intensity and frequency of physical activity in DMD patients can be reliably determined if the appropriate algorithms are used. The high sampling rate (1 s) is particularly appropriate to characterize children’s PA which occurs in short bursts of rapidly changing activity. We hypothesize that such a detailed approach of PA assessment better reflects ‘‘life limiting events” which are relevant for patients with neuromuscular disorders. doi:10.1016/j.nmd.2009.06.183
M.P.3.03 6-minute walk test in Duchenne muscular dystrophy: Longitudinalobservations Henricson 1, R.T. Abresch 1, A. Nicorici 1, C. McDonald1, E. L. Atkinson 2, A. Reha 2, G.L. Elfring 2, L.L. Miller 2 1
University of California, Davis School of Medicine, Davis, CA, United States, 2 PTC Therapeutics, Inc., South Plainfield, NJ, United States Background: Walking abnormalities are prominent in Duchenne/ Becker muscular dystrophy (DMD/BMD). As a prelude to a Phase 2b 48-week registration trial of ataluren (PTC124TM) in DMD/BMD, a short-term observational study established the feasibility of a 6minute walk test (6MWT) in boys with DMD and documented ambulation differences relative to healthy controls. Methods: This longterm follow-up provides data on 6-minute walk distance (6MWD) (DMD n = 12; healthy n = 9) and stride length (DMD n = 9; healthy n = 7) for observational study participants who underwent repeat testing 1 year after initial testing. Results: Median [range] age at repeat testing was similar at 8.5 [5–12] years for boys with DMD and 8 [5–12] years for healthy controls. After 1 year, respective height and weight increased from median [range] of 129 [104–151] cm to 134 [112–169] cm and 35 [18–70] kg to 43 [20–77] kg for boys with DMD and from 136 [122–154] cm to 143 [128–159] cm and 35 [22– 72] kg to 42 [28–79] kg for healthy boys. 6MWD decreased in 9/12 (75%) boys with DMD (median [range] from 350 [252–481] m to 304 [150–530] m) and increased in 7/8 (88%) healthy boys (median [range] from 616 [525–687] m to 620 [590–724] m). Stride length decreased in 7/10 (70%) boys with DMD (median [range] from 0.93 [0.69–1.21] m to 0.91 [0.63–1.25] m) and was maintained or increased in 7/7 (100%) healthy boys (median [range] from 1.50 [1.24–1.66] m to 1.51 [1.41–1.70] m). Conclusions: Most boys with DMD experience declines in ambulation over 1 year with changes that diverge from those in healthy control boys. Stabilization or improvement in 6MWD with 48 weeks of ataluren treatment in
FUNCTIONAL MUSCLE PRESENTATIONS
TESTING
AND
MYOMETRY;
POSTER
M.P.3.01 Gait steadiness and upper-body kinematics in DMD children R. Ganea 1, N. Goemans 2, M. van den Hauwe 2, K. Aminian 1, A. Paraschiv-Ionescu 1, P.Y. Jeannet3 1 Laboratory of Movement Analysis and Measurement, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, 2 Neuromuscular Center & Department of Child Neurology, Universitair Ziekenhuis Gasthuisberg, Leuven, Belgium, 3 Pediatric Neuromuscular Center, Department of Pediatrics, CHUV, Pediatrics, Lausanne, Switzerland
New tools that better assess life-limiting-events in neuromuscular disorders are needed as outcome measures in clinical trials. Quantitative assessment of movement patterns during walking in DMD patients is potentially an objective evaluation of disease severity. While lower limbs initiate and sustain locomotion, motion of the trunk is important for maintaining balance and may be characterized by a dynamic pattern that change with disease progression. Method: The gait pattern of 21 DMD children (age = 8.5 ± 1.7) and 17 agematched healthy controls was analyzed during free walking over 200 m with one gyroscope on each leg and a 3D kinematical sensor (accelerometers and gyroscopes) on the trunk. Gait steadiness (an indicator of compensatory adaptation to the motor deficit) was quantified from (1) the range and step-to-step variability of trunk angular velocity norm (R-AVe), also quantified by median absolute deviation (MAD-AVe) and (2) the smoothness of trunk acceleration norm quantified by spectral entropy (SE-Acc). The MFM scale was used to assess disease severity. Results: The values of R-AVe, MADAVe and SE-Acc were significantly greater in DMD patients (62 ± 9°/s, 11.4 ± 3.7°/s, 0.75 ± 0.06, respectively) compared to healthy control (49.4 ± 7.4°/s, 8.2 ± 1.8°/s, 0.6 ± 0.07), independently of the walking speed which was lower in DMD (0.9 ± 0.17 m/s) compared to control (1.13 ± 0.12 m/s). Higher values were found in more severely affected patients. Discussion: This study shows that upperbody compensatory movement to maintain dynamic balance in DMD patients can be quantified during free-walking over 200 m. These in-lab validated parameters will allow the quantification of walking patterns recorded under long-term daily-life conditions while wearing a single kinematical sensor on the trunk. We hypothesize that the development of such new assessment parameters during gait may allow a better definition and quantification of functional limitation in neuromuscular disorders. doi:10.1016/j.nmd.2009.06.182
M.P.3.02 Detailed analysis of daily-life physical activity patterns in DMD children P.Y. Jeannet1, R. Ganea 2, C. Piot 1, N. Goemans 3, M. van den Hauwe 3, K. Aminian 2, A. Paraschiv-Ionescu 2 1
Pediatric Neuromuscular Center, Department of Pediatrics, CHUV, Lausanne, Switzerland, 2 Laboratory of Movement Analysis and Measurement, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, 3 Neuromuscular Center & Department of Child Neurology, Universitair Ziekenhuis Gasthuisberg, Leuven, Belgium Activity monitors are now used as outcome measures in neuromuscular disorders, but they often monitor limited aspects of physical activity. The aim of this study was to provide a detailed analysis of daily-life physical activity (PA). In 20 ambulatory DMD boys, age 8.5 ± 1.7 y and 18 age-matched healthy controls age
601
8.3 ± 2.2 y. PA was monitored during 3 consecutive days, using a chest worn data-logger (PhysilogÒ) with a 3D inertial sensor (accelerometers and gyroscopes). Body posture and walking parameters were quantified. Gait smoothness was also assessed through quantification of spectral entropy of trunk acceleration pattern. The MFM scale was used to assess disease severity. Results: Time (in %) spent standing and walking in DMD vs. controls was 47.27 ± 9.48, 14.12 ± 5.13 vs. 55.12 ± 9.79, 19.40 ± 5.45. Time (in %) spent sitting and lying in DMD (45.4 ± 8.04, 7.31 ± 5.10) was increased compared to controls (38.91 ± 7.4, 5.95 ± 5.5). The number of walking episodes longer than 1 min and longer than 6 min were decreased compared to controls (7.61 ± 4.7, 0.11 ± 0.26 vs. 11.58 ± 6.5, 0.4 ± 0.6), the same was true for the maximum continuous walking duration and the maximum cadence, (217.39 ± 115.82, 180.27 ± 5.48 vs. 371.86 ± 211.56, 181.88 ± 3.34). Gait pattern was smoother in controls than in DMD (0.71 ± 0.08 vs. 0.61 ± 0.01). There was an overall significant correlation (p < 0.05) between the MFM scores and time spent walking, r = 0.48, number of walking episodes longer than 1 min, r = 0.5 and maximum cadence, r = 0.71. Discussion: This study shows that the type, duration, intensity and frequency of physical activity in DMD patients can be reliably determined if the appropriate algorithms are used. The high sampling rate (1 s) is particularly appropriate to characterize children’s PA which occurs in short bursts of rapidly changing activity. We hypothesize that such a detailed approach of PA assessment better reflects ‘‘life limiting events” which are relevant for patients with neuromuscular disorders. doi:10.1016/j.nmd.2009.06.183
M.P.3.03 6-minute walk test in Duchenne muscular dystrophy: Longitudinalobservations Henricson 1, R.T. Abresch 1, A. Nicorici 1, C. McDonald1, E. L. Atkinson 2, A. Reha 2, G.L. Elfring 2, L.L. Miller 2 1
University of California, Davis School of Medicine, Davis, CA, United States, 2 PTC Therapeutics, Inc., South Plainfield, NJ, United States Background: Walking abnormalities are prominent in Duchenne/ Becker muscular dystrophy (DMD/BMD). As a prelude to a Phase 2b 48-week registration trial of ataluren (PTC124TM) in DMD/BMD, a short-term observational study established the feasibility of a 6minute walk test (6MWT) in boys with DMD and documented ambulation differences relative to healthy controls. Methods: This longterm follow-up provides data on 6-minute walk distance (6MWD) (DMD n = 12; healthy n = 9) and stride length (DMD n = 9; healthy n = 7) for observational study participants who underwent repeat testing 1 year after initial testing. Results: Median [range] age at repeat testing was similar at 8.5 [5–12] years for boys with DMD and 8 [5–12] years for healthy controls. After 1 year, respective height and weight increased from median [range] of 129 [104–151] cm to 134 [112–169] cm and 35 [18–70] kg to 43 [20–77] kg for boys with DMD and from 136 [122–154] cm to 143 [128–159] cm and 35 [22– 72] kg to 42 [28–79] kg for healthy boys. 6MWD decreased in 9/12 (75%) boys with DMD (median [range] from 350 [252–481] m to 304 [150–530] m) and increased in 7/8 (88%) healthy boys (median [range] from 616 [525–687] m to 620 [590–724] m). Stride length decreased in 7/10 (70%) boys with DMD (median [range] from 0.93 [0.69–1.21] m to 0.91 [0.63–1.25] m) and was maintained or increased in 7/7 (100%) healthy boys (median [range] from 1.50 [1.24–1.66] m to 1.51 [1.41–1.70] m). Conclusions: Most boys with DMD experience declines in ambulation over 1 year with changes that diverge from those in healthy control boys. Stabilization or improvement in 6MWD with 48 weeks of ataluren treatment in