In Duchenne muscular dystrophy, which muscle groups are affected first?

In Duchenne muscular dystrophy, which muscle groups are affected first?

• A. Distal hand muscles
• B. Facial muscles
• C. Proximal lower extremities
• D. Intercostal muscles

Answer: (C)

The muscles that are first affected are the proximal lower-extremity muscles around the hips and thighs. In Duchenne muscular dystrophy, dystrophin deficiency causes early weakness in the large, weight-bearing muscles used for standing, climbing stairs, and getting up from the floor. This leads to a classic gait pattern and a Gowers’ sign as the person uses the hands to push up from the floor. Distal hand muscles are typically spared early, and intercostal and facial muscles tend to be affected later in the disease course. So the initial weakness centers on the proximal lower limbs, which is why that option is the best choice.

The muscles that are first affected are the proximal lower-extremity muscles around the hips and thighs. In Duchenne muscular dystrophy, dystrophin deficiency causes early weakness in the large, weight-bearing muscles used for standing, climbing stairs, and getting up from the floor. This leads to a classic gait pattern and a Gowers’ sign as the person uses the hands to push up from the floor. Distal hand muscles are typically spared early, and intercostal and facial muscles tend to be affected later in the disease course. So the initial weakness centers on the proximal lower limbs, which is why that option is the best choice.