Chief Complaint: 19-year-old non-ambulatory male with pneumonia.
History: James Fenlow, a 19-year old male, is immobile and hospitalized for pneumonia. He has a
long history of progressive weakening of his muscles. In the first year of his life, James reached many
gross motor skill milestones, such as holding his head up, rolling over, sitting, and standing, at normal
times. However, he did not walk until age 16 months, and by age two, started to assume a lordotic
posture while standing but not while sitting. A Gower's sign was noted by age four, as was a
Trendelenberg gait. Over the next several years, he suffered progressive muscle weakness, most
notably in the proximal musculature of the arms, pelvis, and legs. By age 9, he required orthotic
braces to assist his walking, and by age 11, he was confined to wheelchair ambulation. In his early
teen years, James was still able to use eating utensils, write, and type on a keyboard, though these
functions have declined over the past year. At 16, he was hospitalized with bronchitis requiring
antibiotic treatment, but recovered. Throughout the years, James has had no history of muscle pain
or spasm, chest pain, or irregular heartbeat. He was diagnosed with a learning disability in the fourth
grade, but has progressed through the grades with tutorial assistance. The only medications that he
normally takes are calcium and fluoride supplements. James has a younger sister in good health and
a younger brother (age 10) who is confined to a wheelchair with problems similar to James's. No
other immediate or distant family members have musculoskeletal difficulties.
Physical Examination: On examination, James appeared fatigued and short of breath. Vital signs:
(1) heart rate = 104 beats per minute, (2) respiratory rate = 28 breaths per minute, (3) temperature
(oral) = 102.4 degrees F, and (4) blood pressure = 138 / 74. Pupils were normal and reactive to light,
with ocular movements intact. No dysarthria or facial muscle weakness was noted. Percussion of the
thorax suggested pulmonary infiltrates in the lower lung fields bilaterally. Breath sounds were
reduced, with significant inspiratory rales heard over both lungs. His cough was very weak, but
productive of green sputum. Heart sounds were normal, with no murmur. Bowel sounds were normal.
Musculoskeletal exam revealed a scoliotic deformity of the spine when James sat up. Upper chest,
shoulder, and thigh muscles were significantly atrophied, but the calf muscles appeared enlarged.
Bilateral elbow contractures limited elbow extension to 80 degrees. Bilateral Achilles contractures
were also present. Muscle strength was reduced in the biceps and triceps brachii muscles bilaterally
(+2 on a scale from 0 to +5, +5 being normal), deltoids (+1), and he was not able to move either thigh
into flexion or extension. Muscle stretch reflexes (rated on a scale from 0 to +4, +2 being normal)
were as follows: right and left biceps and triceps brachii (+1), right and left brachioradialis (+1), right
and left patellar reflexes (0), and right and left ankle jerks (+1).
Assignment: Answer the following questions using at least one peer reviewed medical journal article
(use googlescholar.com to search) PER PERSON in the group and any other reputable sources you
can find (e.g. websites devoted to a particular disease, your book, www.cdc.gov, www.nih.gov)
EXCEPT Wikipedia.com.
Questions:
1. At age 4, James underwent a biopsy of the right gastrocnemius muscle. The pathologist's report
noted histopathologic changes suggestive of Duchenne muscular dystrophy. Describe in detail the
typical microscopic changes noted in the muscle tissue of someone with Duchenne's muscular
dystrophy.
A. degenerating skeletal fibers, proliferation of endosmysial connective tissue,
numerous macrophages, excessive contraction (dense fibers), muscle fibers are breaking
down
2. Which muscles are most severely affected by this disease process?
A. Most affected muscles include the muscles of the pelvic girdle, and these are usually
the first to be affected. Gluteal muscles are also weakened in early stages. Hip extensors get
locked in contraction and don’t release.
3. Why did James's calves appear enlarged? What is this condition called?
A. Many muscles start to degenerate and adipose and collagen replace muscle tissue.
There is a build-up of connective tissue in the calf muscle that causes them to enlarge
because the viable cells try to compensate for the cells that are dead.
4. At the time of diagnosis, James had an elevated serum creatine kinase (i.e. creatine
phosphokinase) level of 26,000 IU / L (normal level is <160 IU / L). What is creatine kinase, and why
was this level elevated in James's blood? (Be specific.)
A. Creatine Kinase is an enzyme in skeletal muscle cells that transfers phosphate
groups between creatine phosphate and ADP. It’s a large storage area for high energy
phosphate bonds. When muscles are at rest there’s high ATP, and ATP is used when there’s a
contraction. Large amounts of CK in blood is indicative of muscle cell destruction. Because
Duchenne muscular dystrophy causes muscle cell membranes to break down it release CK
into the blood stream.
5. What is a Gower's sign, and why did James have it?
A. Weakness in proximal leg muscles, he has it because he has muscle duchenne
dystrophy. He uses his hands to compensate for the weakened leg muscles.
6. Why did James have a lordotic posture early on?
A. Weakness of the erector spinae muscles make it difficult to stand in an erect position.
This moves his center of gravity forward, helping him stay balanced when standing.
7. Why did James develop scoliosis?
A. his leg muscles became weak and he started using a wheel chair, conforming to a
wheel chair causes scoliosis to worsen.
8. Why is it important for James to take calcium and fluoride supplements?
A. Because his muscles continue to weaken and he becomes less mobile. A more still
lifestyle causes bone mass to decrease. These supplements help stimulate bone mass and
development.
9. Describe what is known about the cause of Duchenne muscular dystrophy. (Be specific and
detailed in your answer.)
A. it is an x-linked recessive genetic disorder. Mother could be carrier of the gene and
pass it down to the son or there’s a mutation in the DNA during replication. Its on Xp21 on the
X-chromosome.
10. What are contractures, and why has James developed them?
A. these are caused by tightening of muscles and reduced mobility of muscles.
Individual develop tightening and shortening of gastrocnemius muscles and therefore
shortening of achiles tendon primarily because feet assume plantar flexion in bedridden or
wheel-chair bound individuals
11. How might a physical therapist help James?
A. Active and passive range of motion can help with delaying the destruction and
weakening of muscles.