Muscular Dystrophies And Spinal Muscular Atrophies

Question 1

What is the pathology of muscular dystrophy?

Answer 1

-Dystrophin is a large protein that stabilizes the cell membrane during muscle contractions
-Without dystrophin, the cell wall is unstable, cell homeostasis is impaired and myofiber deteriorates
-There is some regeneration but the muscle is replaced by fat and connective tissue

Question 2

What happens if someone does not have dystrophin?

Answer 2

-Muscle hypoxia as a result of a vascular response to exercise
-Progressive loss of muscle contractility
-Destruction of the myofibrils and replacement with fat and connective tissue

Question 3

Duchene MD and Becker MD?

Answer 3

Duchenes is evident between the ages of 1-5 years and Beckers is evident between 5-10 years

Question 4

What are the secondary impairments of muscular dystrophy?

Answer 4

-Contractures/postural malalignment
-Scoliosis
-Decreased respiratory capacity
-Cardiac dysfunction
-Impaired GI mobility
-Easily fatigued
-Cognitive impairments

Question 5

What are the signs of DMD?

Answer 5

-CALF HYPERTROPHY (first sign) (pseudohypertrophy)
-deltoid, quads, FA extensor muscle groups as well as
-Weak in the neck flexors, abs, interscaps, hips
-GOWERS SIGN

Question 6

Gait of someone with DMD?

Answer 6

-Wide BOS, lateral trunk sway
-Scap retraction
-Increased lordosis
-Forward trunk lean
-Intoeing from TFL being used to advance swing
-Lack of reciprocal arm swing

Question 7

What are the functional measures for DMD?

Answer 7

-Vignos functional rating scale
-North star ambulatory assessment
-Egen klassification
-Barthel index
-Pedi
-SFA (from kindergarten to the 6th grade)

Question 8

Interventions for DMD?

Answer 8

-NO ECCENTRIC OR HIGH RESISTANCE TRAINING
-key muscle groups are abs, hip extensors and ABDs, knee extensors
-Do not exercise to exhaustion due to the risk of exercise induced muscle damage
-Submaximal low impact aerobic exercise

Question 9

What is Becker muscular dystrophy?

Answer 9

Milder version of DMD
-Short arm X chromosome
-Altered size and decreased amount of dystrophin

Question 10

What are the impairments of Becker muscular dystrophy?

Answer 10

-Gastroc contracture
-Proximal weakness
-Increased presence of cardiac involvement
-Dilated cardiac myopathy
-CLUMSY CHILD and progresses to an increasing number of falls

Question 11

What is spinal muscle atrophy?

Answer 11

-Caused by the mutation of the SMN 1 gene
-Loss of anterior horn cells in the spinal cord

Question 12

What are the types of SMA?

Answer 12

-Type 1: 0-4 months
Rapidly progressive, severe weakness, mortality dependent on aggressiveness or respiratory support. Typically 1-10 years
-Type II: 6-12 months, recessive (most common)
Initial progression that becomes slowly progressive over years, moderate to severe weakness
-Type III: 1-10 years, recessive
Slowly progressive, mild impairment

Question 13

What are the PT goals for SMA?

Answer 13

-Prevent deformity
-Prolong function by maintaining capacity of ADL’s
-Facilitate movement
-ROM to prevent contractures
-Strengthening in the early stages
-Alternaives to sitting position
-Skin care
-ADLs