Deck 23: Duchenne Muscular Dystrophy

Question 1

As Duchenne muscular dystrophy progresses, the greatest life-threatening concerns are

A) cerebral hemorrhage and seizures.
B) pulmonary infections and cardiomyopathy.
C) cerebral thrombosis and seizures.
D) neoplasms and cardiac arrest.

Answer 1

B
Explanation: Weakness of the muscles of respiration causes difficulty with breathing and in mobilizing pulmonary secretions. As a result, more than 70% of patients succumb to pulmonary complications (Emery, 2003). Cardiac manifestations include arrthymia and/or cardiomyopathy (Chénard et al, 1993; De Kermadec et al, 1994). Although a majority of boys will develop cardiac involvement, the severity of the problem varies greatly; fewer than 30% of boys die as a result of cardiac complications (Emery 2003).

Question 2

The validity, reliability, and sensitivity of manual muscle testing, range of motion, testing, and timed function tests have been established in patients with Duchenne muscular dystrophy

Answer 2

True
Explanation: Refer to studies by Pandya, et al (1985); Florence, J. M., et al (1984); and Florence, J. M., et al (1992).

Question 3

Duchenne muscular dystrophy is an

A) autosomal recessive disorder.
B) autosomal dominant disorder.
C) X-linked recessive disorder.
D) acquired disorder.

Answer 3

C
Explanation: Boys carry XY chromosomes, whereas girls carry XX chromosomes. Therefore, a gene for DMD on the X chromosome causes boys to be affected and girls to be carriers (Bushby et al., 2010a).

Question 4

Surgical correction of scoliosis and spinal stabilization are considered cosmetic procedures that do not improve function or longevity for boys with Duchenne muscular dystrophy.

Question 5

Among male births, the incidence of Duchenne muscular dystrophy is variably reported as 1 in:

A) 800 to 1,000.
B) 3,500 to 6,000.
C) 6,000 to 8,000.
D) 8,000 to 10,000.

Question 6

Boys with Duchenne muscular dystrophy tend to use the Gowers' maneuver to rise from the floor because of weakness in

A) hip flexors, extensors, and abductors.
B) hip flexors and extensors, and knee extensors.
C) hip extensors, knee flexors, and extensors.
D) hip extensors and abductors and knee extensors.

Question 7

Duchenne muscular dystrophy is associated with an absence of

A) dystrophin.
B) red blood cells.
C) white blood cells.
D) platelets.

Question 8

In boys with Duchenne muscular dystrophy, muscle weakness appears first in the

A) cardiac and respiratory muscles.
B) ankle plantar flexors, facial muscles, muscles involved in speech, and sphincters.
C) neck flexors, abdominal muscles, hip extensors and abductors, and knee extensors.
D) finger flexors and extensors, wrist and elbow flexors.

Question 9

Physical therapy intervention for young boys with Duchenne muscular dystrophy should include

A) rigorous progressive resistive exercises.
B) daily stretching and promotion of regular age-appropriate physical activity.
C) gait training with a posture-control walker.
D) functional electrical stimulation.

Question 10

Development of contractures in boys with Duchenne muscular dystrophy has been documented to occur in which following sequence?

A) Heel cords, IT band/TFL, hip flexors
B) Hip flexors, knee flexors, elbow flexors
C) Heel cords, knee flexors, hip flexors
D) Hip flexors, elbow flexors, wrist flexors

Question 11

Corticosteroids have been found to improve muscle mass and function in the short term, but prolonged use does not affect outcomes in boys with Duchenne muscular dystrophy.

Question 12

Duchenne muscular dystrophy affects skeletal muscle, cardiac muscle, and smooth muscle of the gastrointestinal tract but is not associated with learning disabilities.

Question 13

Some boys who are delayed in their development of ambulation and speech are later diagnosed with Duchenne muscular dystrophy.

Question 14

Ambulation can be prolonged for boys with Duchenne muscular dystrophy through the use of knee-ankle-foot orthoses and contracture-release surgery, augmented by daily stretching, functional activities, and swimming.

Question 15

For boys with Duchenne muscular dystrophy, function can be maintained using all of the following interventions except

A) corticosteroids.
B) scoliosis surgery.
C) aggressive strengthening exercises.
D) knee-ankle-foot orthoses.

Question 16

A pharmacological intervention that can prolong ambulation for boys with Duchenne muscular dystrophy is

A) nonsteroidal anti-inflammatory medications.
B) chemotherapy.
C) antimalarials.
D) corticosteroids.