Duchenne Muscular Dystrophy Flashcards
(37 cards)
What is DMD the result of?
mutations in dystrophin gene (protein)
results in progressive muscle degeneration
What kind of genetic mutation is DMD?
X linked recessive (though can occur secondary to a spontaneous mutation
how does the weakness progress?
Proximal to distal
Who are the carriers?
Women are the carriers but usually exhibit no symptoms
When is there loss of ambulation without Tx?
Typically between 7-12 y.o.
Can the natural history be changed? if yes how?
Yes, by targeting interventions to known manifestations and complications. (steroids, etc)
When is DMD typically diagnosed?
5 years of age
What are the initial sx?
Abnormal muscle function.
Delayed walking, frequent falls, difficulty running/climbing stiars, gowers sign, gait abnormalities, pseudo hypertrophy of calves, increased CK
DMD effects on MSK system
Mechanical damage; increased permeability of muscle membrane, reduced blood flow to skeletal muscle during exercise, decreased bone mineral density.
What does mechanical damage lead to?
Decreased tissue compliance/elasticity, loss of regenerative capability, fibrosis, increased collagen density, reduced maximal force production and fatigue resistance.
What is mechanical damage?
Dystrophin provides stability to muscles during function, without it muscle is more vulnerable to damage. Dystrophin increases tensile strength. Chronic damage/muscle breakdown (increased serum CK)
Stages of DMD
Pre-Symptomatic Early ambulatory Late ambulatory Early non-ambulatory Late non-ambulatory
Pre-symptomatic DMD
Possible developmental delay (freq falls, dealyed motor milestones etc)
Gait abnormalities not typically evident
Generally not Dx during this phase
Early Ambulatory DMD
GOWERS SIGN!
Waddling gait/duchenne jog
Can climb stairs with compensatory pattern
May see some imp in gross motor but plateau eventually
No specialized mobility equipment typically needed prior to school age
Late ambulatory DMD
Increasingly labored gait
Loss of ability to climb stairs and rise from floor ind
Difficulty with antigravity extension
inc LE contractures with dc amb
decreased mot to participate
access to mobility device may help keep up with peers
Early non-ambulatory
Typically able to sit ind, bed mobility may be difficult
Often need adaptive equipment and some assistance with bathing, toileting, and transfers
might be able to self propel wheelchair might not
increased risk for scoliosis
Late non-ambulatory
UE function, postural maintenance and bed mobility increasingly limited.
Increased need for caregiver assistance for all ADLs/repositioning
Increasing need for assistive technology
Increasing use of respiratory support
Increasing reports of chronic pain
Pharmocological interventions
Glucocorticoids
Deflazacort
Glucocorticoids
currently the only med that slows decline in muscle strength and function in DMD. Helps preserve ambulation, minimize resp, cardiac and orthopedic complications.
Deflazacort or Prednisone
Work similarly. Deflazacort not currently approved by FDA. lower risk of weight gain.
Initiatio of Glucocorticoid therapy
not rec for child who is still gaining motor skills, rec during plateau phase (no progress with motor skills, prior to decline (4-8 y.o.)
Use of glucocorticoids after loss of ambulation
Medication continued to help preserve upper limb strength, reduce progression of scoliosis, and delay decline in respiratory and cardiac function
Glucocorticoids side effects
Cushingoid features Weight gain, obesity Growth suppression Bone demineralization Increased fracture risk Adverse behavioral changes Delayed puberty Increased susceptibility to infection Hypertension Glucose intolerance Cataracts
areas of psychosocial risk
Social functioning due to biological or physical limitations
Learning disorders and/or cognitive delays
Speech and language deficits
Neurobehavioral and/or neurodevelopmental disorders
Oppositional/argumentative behavior
Anxiety or depression (patient and family)
