Alexander R Dietz1, Anne Connolly2, Amir Dori3, Craig M Zaidman4. 1. Blue Sky Neurology, Englewood, CO, USA; Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA. 2. Department of Pediatrics, Division of Neurology, Nationwide Children's Hospital, Columbus OH, USA. 3. Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA; Department of Neurology, Talpiot Medical Leadership Program, Chaim Sheba Medical Center, Tel HaShomer, and Joseph Sagol Neuroscience Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. 4. Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA. Electronic address: zaidmanc@wustl.edu.
Abstract
OBJECTIVE: Absent or truncated dystrophin in Duchenne (DMD) and Becker (BMD) muscular dystrophies results in impaired vasodilatory pathways and exercise induced muscle ischemia. Here, we used power Doppler sonography to quantify changes in intramuscular blood flow immediately following exercise in boys with D/BMD. METHOD: We quantified changes in intramuscular blood flow following exercise using power Doppler sonography in 14 boys with D/BMD and compared changes in muscle blood flow to disease severity and to historic controls. RESULT: Post exercise blood flow change in the anterior forearm muscles is lower in (1) DMD (median 0.25%; range -0.47 to 2.19%) than BMD (2.46%; 2.02-3.38%, p < 0.05) and historical controls (6.59%; 2.16-12.40%, p < 0.01); (2) in non-ambulatory (0.04%; -0.47 to 0.10%) than ambulatory DMD boys (0.71%; 0.07-2.19%, p < 0.05); and (3) in muscle with higher echointensity (rs = -0.7253, p = 0.005). The tibialis anterior showed similar findings. We estimate that a single sample clinical trial would require 19 subjects to detect a doubling of blood flow to the anterior forearm after the intervention. CONCLUSION: Post-exercise blood flow is reduced in D/BMD and relates to disease severity. SIGNIFICANCE: Our protocol for quantifying post-exercise intramuscular blood flow is feasible for clinical trials in D/BMD.
OBJECTIVE: Absent or truncated dystrophin in Duchenne (DMD) and Becker (BMD) muscular dystrophies results in impaired vasodilatory pathways and exercise induced muscle ischemia. Here, we used power Doppler sonography to quantify changes in intramuscular blood flow immediately following exercise in boys with D/BMD. METHOD: We quantified changes in intramuscular blood flow following exercise using power Doppler sonography in 14 boys with D/BMD and compared changes in muscle blood flow to disease severity and to historic controls. RESULT: Post exercise blood flow change in the anterior forearm muscles is lower in (1) DMD (median 0.25%; range -0.47 to 2.19%) than BMD (2.46%; 2.02-3.38%, p < 0.05) and historical controls (6.59%; 2.16-12.40%, p < 0.01); (2) in non-ambulatory (0.04%; -0.47 to 0.10%) than ambulatory DMDboys (0.71%; 0.07-2.19%, p < 0.05); and (3) in muscle with higher echointensity (rs = -0.7253, p = 0.005). The tibialis anterior showed similar findings. We estimate that a single sample clinical trial would require 19 subjects to detect a doubling of blood flow to the anterior forearm after the intervention. CONCLUSION: Post-exercise blood flow is reduced in D/BMD and relates to disease severity. SIGNIFICANCE: Our protocol for quantifying post-exercise intramuscular blood flow is feasible for clinical trials in D/BMD.
Authors: Christopher Lopez; Tanja Taivassalo; Maria G Berru; Andres Saavedra; Hannah C Rasmussen; Abhinandan Batra; Harneet Arora; Alex M Roetzheim; Glenn A Walter; Krista Vandenborne; Sean C Forbes Journal: J Appl Physiol (1985) Date: 2021-05-20
Authors: Matthias R Lambert; Janelle M Spinazzola; Jeffrey J Widrick; Anna Pakula; James R Conner; Janice E Chin; Jane M Owens; Louis M Kunkel Journal: Mol Ther Date: 2020-11-20 Impact factor: 11.454