Kavya S Nair1, Donovan J Lott1, Sean C Forbes1, Alison M Barnard1, Rebecca J Willcocks1, Claudia R Senesac1, Michael J Daniels2, Ann T Harrington3, Gihan I Tennekoon4, Kirsten Zilke5, Erika L Finanger5, Richard S Finkel6, William D Rooney7, Glenn A Walter8, Krista Vandenborne1. 1. Department of Physical Therapy, University of Florida, Gainesville, FL, USA. 2. Department of Statistics, University of Florida, Gainesville, FL, USA. 3. Center for Rehabilitation, Children's Hospital of Philadelphia, Philadelphia, PA, USA. 4. Department of Neurology and Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA. 5. Department of Pediatrics and Neurology, Oregon Health & Science University, Portland, OR, USA. 6. Center for Experimental Neurotherapeutics, St. Jude Children's Research Hospital, Memphis, TN, USA. 7. Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, USA. 8. Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, USA.
Abstract
BACKGROUND: Muscles of boys with Duchenne muscular dystrophy (DMD) are progressively replaced by fatty fibrous tissues, and weakness leads to loss of ambulation (LoA). Step activity (SA) monitoring is a quantitative measure of real-world ambulatory function. The relationship between quality of muscle health and SA is unknown in DMD. OBJECTIVE: To determine SA in steroid treated boys with DMD across various age groups, and to evaluate the association of SA with quality of muscle health and ambulatory function. METHODS: Quality of muscle health was measured by magnetic resonance (MR) imaging transverse magnetization relaxation time constant (MRI-T2) and MR spectroscopy fat fraction (MRS-FF). SA was assessed via accelerometry, and functional abilities were assessed through clinical walking tests. Correlations between SA, MR, and functional measures were determined. A threshold value of SA was determined to predict the future LoA. RESULTS: The greatest reduction in SA was observed in the 9- < 11years age group. SA correlated with all functional and MR measures.10m walk/run test had the highest correlation with SA. An increase in muscle MRI-T2 and MRS-FF was associated with a decline in SA. Two years prior to LoA, SA in boys with DMD was 32% lower than age matched boys with DMD who maintained ambulation for more than two-year period. SA monitoring can predict subsequent LoA in Duchenne, as a daily step count of 3200 at baseline was associated with LoA over the next two-years. CONCLUSION: SA monitoring is a feasible and accessible tool to measure functional capacity in the real-world environment.
BACKGROUND: Muscles of boys with Duchenne muscular dystrophy (DMD) are progressively replaced by fatty fibrous tissues, and weakness leads to loss of ambulation (LoA). Step activity (SA) monitoring is a quantitative measure of real-world ambulatory function. The relationship between quality of muscle health and SA is unknown in DMD. OBJECTIVE: To determine SA in steroid treated boys with DMD across various age groups, and to evaluate the association of SA with quality of muscle health and ambulatory function. METHODS: Quality of muscle health was measured by magnetic resonance (MR) imaging transverse magnetization relaxation time constant (MRI-T2) and MR spectroscopy fat fraction (MRS-FF). SA was assessed via accelerometry, and functional abilities were assessed through clinical walking tests. Correlations between SA, MR, and functional measures were determined. A threshold value of SA was determined to predict the future LoA. RESULTS: The greatest reduction in SA was observed in the 9- < 11years age group. SA correlated with all functional and MR measures.10m walk/run test had the highest correlation with SA. An increase in muscle MRI-T2 and MRS-FF was associated with a decline in SA. Two years prior to LoA, SA in boys with DMD was 32% lower than age matched boys with DMD who maintained ambulation for more than two-year period. SA monitoring can predict subsequent LoA in Duchenne, as a daily step count of 3200 at baseline was associated with LoA over the next two-years. CONCLUSION: SA monitoring is a feasible and accessible tool to measure functional capacity in the real-world environment.
Authors: Donovan J Lott; Sean C Forbes; Sunita Mathur; Sean A Germain; Claudia R Senesac; H Lee Sweeney; Glenn A Walter; Krista Vandenborne Journal: Neuromuscul Disord Date: 2014-04-13 Impact factor: 4.296
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Authors: R J Willcocks; I A Arpan; S C Forbes; D J Lott; C R Senesac; E Senesac; J Deol; W T Triplett; C Baligand; M J Daniels; H L Sweeney; G A Walter; K Vandenborne Journal: Neuromuscul Disord Date: 2014-01-11 Impact factor: 4.296
Authors: Alison M Barnard; Rebecca J Willcocks; William T Triplett; Sean C Forbes; Michael J Daniels; Saptarshi Chakraborty; Donovan J Lott; Claudia R Senesac; Erika L Finanger; Ann T Harrington; Gihan Tennekoon; Harneet Arora; Dah-Jyuu Wang; H Lee Sweeney; William D Rooney; Glenn A Walter; Krista Vandenborne Journal: Neurology Date: 2020-02-05 Impact factor: 9.910