Journal of Genetic Syndromes & Gene Therapy
Open Access

Abstract

Prediction of Loss of Gait in Duchenne Muscular Dystrophy Using the Ten Meter Walking Test Rates

Tatiana Maciel Pizzato, Cyntia Rogean de Jesus Alves de Baptista, Edson Zangiacomi Martinez, Claudia Ferreira da Rosa Sobreira and Ana Claudia Mattiello-Sverzut

Objective: To evaluate the performance of boys with DMD in the ten-meter walking test (10MWT) in order to predict gait loss. Method: This longitudinal study consisted of consecutive evaluations, minimum of 3 and maximum of 12, conducted every 4 months, during 33 months, depending on time of inclusion in the study. Ambulant boys with DMD (n=18), ages 4 to 13 yrs, mean 7 (sd=2.22), were assigned to Ambulatory group (A; n=11) or Non-Ambulatory group (NA; n=7) according to their status at the end of the study. Diagnosis was based on the absence of dystrophin in a muscle biopsy and/or identification of a mutation of the dystrophin-gene. The main outcome measures were: 10MWT total time and rates between two consecutive sessions. Secondary measures included: functional status and muscle strength of the hip, knee and ankle. Results: The 10MWT total time for the NA group oscillated over time, while remaining steady for the A group. The NA group showed mean of 16.18 seconds (CI 95% 14.38–17.98) and the A group showed mean of 10.2 seconds (CI 95% 9.08–11.24). The difference between groups was estimated as -5.98 seconds (CI 95%-8.11; -3.89). The linear model of mixed effects identified significant increase in 10MWT time for the NA group and decrease for the A group. The rates were>1.25 for participants who became wheelchair users, indicating increased time to perform 10MWT overtime. Conclusions: Rates ≥ 1.25 indicate the borderline between independent gait and wheelchair confinement and are useful for predicting gait loss.