Muscular Dystrophies, Spinal Muscular Atrophy (SMA), Friedreich’s ataxia Flashcards
1
Q
What lab value would be elevated when diagnosing someone with muscular dystrophy?
A
Muscle enzyme creatine phosphokinase
2
Q
T/F: Duchenne’s muscular dystrophy (DMD) is an X-linked disorder
A
True
3
Q
What protein is missing in DMD?
A
- Dystrophin
- Dystrophin-associated proteins (DAPs) enhance and transmit tensile force
4
Q
What happens if dystrophin or DAPs are missing?
A
- Fragile muscle membrane during contraction
- Muscle hypoxia from atypical vascular response to exercise
- This combination results in progressive loss of contractility
5
Q
What is nebulin for?
A
- Proper muscle alignment during contraction
- Decreases in amount as clinical signs/symptoms increasingly present
6
Q
What does long-term steroid therapy help with in DMD?
A
- Prolonged walking up to 3 years
- Improved isometric muscle strength
- Improved pulmonary function
- Possible improvement in cognitive skills
- Side effects - weight gain, growth suppression, cataracts, osteoporosis
7
Q
What is lack of dystrophin associated with?
A
- Cardiomyopathy in 84% of boys with DMD
- Cardiac failure secondary to cardiomyopathy
8
Q
Impairments, activity and participation limitations of DMD
A
- Pseudohypertrophy - muscle replaces with fat and connective tissue
- Initial proximal weakness before ROM loss
- ROM loss - tight gastroc-soleus
- Posture - lordosis and mild scap winging; scoliosis
- Activity limitation - inability to climb stairs and ambulate from 7-13 y/o
- Intellectual impairment - 1/3 of children with DMD
9
Q
Assessment of patient with DMD includes:
A
- MMT
- PROM
- Respiratory function
- Spinal deformities
- Gait - North Star Ambulatory assessment
- Functional abilities
- Adaptive equipment assessment
- Emotional status
- Pediatric QOL questionnaire
10
Q
What muscles are known to exhibit weakness in DMD?
A
- Neck flexors
- Hip extensors, abductors, flexors
- Knee extensors
11
Q
Assessment tools for DMD
A
- Brooke & Vignos Classification Scales for Children with DMD
- Pediatric Evaluation of Disability Inventory (PEDI)
- School Function Assessment (SFA)
12
Q
Signs of DMD in early school age
A
- Clumsiness
- Falling
- Inability to keep up with peers
- Gait - slight compensated Trendelenburg
- Running accentuates waddling gait
- Gower’s sign - using arms to push on thighs
13
Q
Typical progression of DMD
A
- Stair climbing and standing from the floor are more difficult
- Gait pattern changes - increase BoS, lateral sway, toe walking
- Restrictive pulmonary impairment - decline in max vital capacity
14
Q
What activities are included in PT management for DMD at early school age?
A
- Aerobic conditioning
- Re-strengthening
- Positioning to stretch tight musculature
- Gait 2-3 hrs/day
- No heavy resistance or eccentrics
15
Q
What pulmonary measurements decline into adulthood with DMD?
A
- Forced vital capacity (FVC)
- Peak expiratory flow (PEF)
16
Q
General interventions for DMD
A
- Prevention of contracture
- Preserved independent mobility
- Surgery to maintain gait
- KAFO use
- LE contracture control through surgery
- Spinal stabilization - scoliosis control
17
Q
What is spinal muscular atrophy (SMA)?
A
- Anterior horn cell of the spinal cord and spinal reflex arc are destroyed
- Degeneration of nerve cells
18
Q
Clinical presentation of SMA
A
- Tented mouth
- Paradoxical breathing
- Hypotonia
- Weakness
- Tongue fasciculations
19
Q
How is SMA diagnosed?
A
- Clinical exam
- Lab procedures - CK, EMG, muscle US, muscle biopsy, genetic testing (autosomal recessive)
20
Q
Impairments of SMA
A
- Muscle weakness
- Scoliosis
- Contractures
- Decreased respiratory capacity
- Increased muscle fatigability
21
Q
SMA type I
A
- Werdnig-Hoffman syndrome
- Most severe
- Limp, frog-legged posture
- Weak cry
- Absent DTR
- Tongue fasciculations
- Rapid progression
- May require mechanical vent and G-tube
22
Q
SMA type II
A
- Chronic type
- Proximal weakness - causing scoliosis
- Osteoporosis
- Functional mobility - powered as early as 18 months of age
23
Q
SMA type III
A
- Onset after 18 months
- Proximal weakness - hips, knees, trunk
- Slow developmental progression
- Bilateral Trendelenburg when walking
- Good UE strength
- Slow progression
24
Q
SMA assessment measures
A
- Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND)
- Hammersmith Infant Neurological Assessment (HINE)
- Hammersmith Functional Motor Scale—Expanded (HFMSE)
- Upper Limb Module
25
Non-PT treatments for SMA
* Spinraza - treats underlying defect
* AVXS-101 gene therapy
* Small molecule pill - FIREFISH
26
PT intervention for SMA type I
* Feeding
* ROM
* Positioning
* Respiratory care
* Developmental activities
* Postural control
* Upright
27
What is Friedreich's ataxia (FA)?
* Defect in FXN gene - produces frataxin protein (mitochondrial protein)
* Decreased ability to produce energy
* Buildup of cellular toxins
* Causes progressive NS damage (UMN, LMN, cerebellum)
28
Symptoms of Friedreich's ataxia
* Appears at 5-16 y/o
* Balance impairment and ataxia
* Sensory loss
* Weakness
* Hypotonia and/or spasticity
* Eye movement deficit and nystagmus
* Dysarthria, dysphagia
* Vision and hearing loss
* Cognition and higher function intact
* Scoliosis
* Cardiomyopathy
* Pancrease dysfunction - diabetes
* Restless legs
29
Prognosis of Friedreich's ataxia
* 10-20 yrs after first symptoms -> wheelchair
* Later stages may progress to complete dependence
* Many die due to heart disease
30
PT intervention for Friedreich's ataxia
* Low intensity strengthening
* Core control – scoliosis prevention
* Balance
* Coordination
* Functional activities
* Gait
* Aerobic exercise
