[P3-118] Evaluation of Muscle Oxygenation by Functional Near-infrared Spectroscopy in Duchenne Muscular Dystrophy
Duchenne muscular dystrophy (DMD) is an X-linked debilitating muscular disease of mutations in the gene encoding dystrophin, a cytoskeletal protein that stabilizes the muscle membrane. The lack of dystrophin also disrupts the recruitment of neuronal nitric oxide synthase (nNOS) to the sarcolemma which may decrease NO production and lead to functional muscular ischemia. This study proposed using functional near-infrared spectroscopy (fNIRS) to evaluate the dynamic changes in muscle oxygenation during a 6-minute-walk test (6MWT) and a venous occlusion test (VOT) in DMD patients. A total of 60 subjects (30 DMD patients and 30 age-matched controls) were recruited. The DMD patients were classified into two groups, ambulatory (N=18) and non-ambulatory groups (N=12). Muscle oxygenation of forearm was evaluated noninvasively before, during and after VOT using fNIRS in all participants, while dynamic muscle oxygenation of gastrocnemius muscle during 6MWT was determined using fNIRS in all ambulatory participants and controls. The results revealed that impaired muscle oxygenation was observed during walking in DMD patients. Moreover, the variation of Δ[HbO2] and Δ[Hb] during VOT are significant difference among all three groups. The results implied that worsen muscle function was associated with a slower increase of muscle oxygenation during VOT. Our results suggested that the changes of muscle oxygenation during VOT are suitable for monitoring disease severity of DMD. Therefore, the method of fNIRS possesses great potential in future evaluations of DMD patients that implies a good feasibility for clinical application.