The correlation analysis of functional factors and age with Duchenne muscular dystrophy

Objective: To correlate existing evaluation tools with clinical information on Duchenne muscular dystrophy (DMD) patients following age and to investigate genetic mutation and its relationship with clinical function. Method: The medical records of 121 children with DMD who had visited the pediatric rehabilitation clinic from 2006 to 2009 were reviewed. The mean patient age was 9.9±3.4 years and all subjects were male. Collected data included Brooke scale, Vignos scale, bilateral shoulder abductor and knee extensor muscles power, passive range of motion (PROM) of ankle dorsi-flexion, angle of scoliosis, peak cough flow (PCF), fractional shortening (FS), genetic abnormalities, and use of steroid. Results: The Brooke and Vignos scales were linearly increased with age (Brooke (y1), Vignos (y2), age (x), y ₁=0.345x-1.221, R _Brooke ²=0.435, y ₂=0.813x-3.079, R _Vignos ²=0.558, p<0.001). In relation to the PROM of ankle dorsiflexion, there was a linear decrease in both ankles (right and left R ²=0.364, 0.372, p<0.001). Muscle power, Cobb angle, PCF, and FS showed diversity in their degrees, irrespective of age. The genetic test for dystrophin identified exon deletions in 58.0% (69/119), duplications in 9.2% (11/119), and no deletions or duplications in 32.8% (39/119). Statistically, the genetic abnormalities and use of steroid were not definitely associated with functional scale. Conclusion: The Brooke scale, Vignos scale and PROM of ankle dorsi-flexion were partially available to assess DMD patients. However, this study demonstrates the limitations of preexisting scales and clinical parameters incomprehensively reflecting functional changes of DMD patients.