NM Disorders

Question 1

Most common MD (I in 3500 live births); X-linked recessive; occurs directly in the muscle; diagnosed typically at 5 years, initial sx at 2.5; life span = 20-30 years

Answer 1

Duchenne MD

- not walking by 18 mos = red flag

Question 2

What enzyme do people with DMD lack?

Answer 2

dystrophin

Question 3

What is the significance of decreased dystrophin enzyme?

Answer 3

Decreased enzyme = fragile structure and cannot repair

• you do not want to fatigue m’s so breakdown does not occur
• causes calcium channel leaks with unstable musculature

Question 4

What are symptoms of DMD?

Answer 4

1. Delay in walking
2. Difficulty getting off the floor; Gower’s sign
3. Clumsiness or frequent falling
4. Pseudohypertrophy of the calves; Firm to palpation; decreased necrosis

Question 5

How is DMD diagnosed?

Answer 5

Based on clinical examination:

1. EMG
2. Muscle Biopsy
3. DNA Analysis
4. Laboratory Blood Tests

Question 6

What is the role of the PT in DMD?

Answer 6

1. Identify impairments in body structure and function
2. Promote activity and participation - MDA camp
3. Prevent secondary complications
4. Education

Question 7

What are secondary impairments of DMD?

Answer 7

1. Development of contractures
2. Postural misalignment - Especially in anti-gravity positions
3. Development of Scoliosis
4. Decreased respiratory capacity
5. Fatigue
6. Obesity
7. Mild Intellectual Impairments or Learning Difficulties

Question 8

What is the role of the PT in educating about signs that precurse declines in function and increases in disability?

Answer 8

1. Loss of ambulation
2. Accommodation for adaptive equipment
3. Transition from educational to vocational environment
4. Decisions regarding mechanical ventilation

Question 9

MD type: onset 1-4 years; X-linked; Rapidly progressive; loss of walking by 9-10 years; death in late teens

Answer 9

Duchenne’s

Question 10

MD type: onset 5-10 years; X-linked; Slowly progressive; maintain walking past early teens; life span into third decade

Answer 10

Becker’s

Question 11

MD type: onset at birth; Recessive; Typically slow, but variable, shortened life span

Answer 11

Congenital

Question 12

MD type: onset at birth; Dominant; Typically slow with significant intellectual impairment

Answer 12

Congenital myotonic

Question 13

MD type: onset in first decade; Dominant/Recessive; Slowly progressive loss of walking in later life, variable life expectancy

Answer 13

Child-onset Facioscapulohumeral

Question 14

MD type: onset in childhood to early teens; x-linked; Slowly progressive with cardiac abnormality and normal life span

Answer 14

Emery-dreifuss

Question 15

What are primary impairments of MD?

Answer 15

1. Muscle Weakness secondary to progressive loss of myofibrils
2. Contractures from birth - Congenital; Congenital Myotonic

Question 16

What are goals of treatment for MD?

Answer 16

1. Promote independence
2. Slow progression
3. Improve quality of life

Question 17

What are pharmacologic management of DMD?

Answer 17

1. Use of steroids
2. Experimental use of stem cells
3. Experimental gene replacement therapy

Question 18

What is medical management of DMD?

Answer 18

1. Steroids (weak evidence for creatinine use)
2. Surgical contracture management
3. Conservative management of scoliosis through bracing

Question 19

What are side effects of steroid use?

Answer 19

1. Weight Gain
2. Growth Suppression
3. Osteoporosis

Question 20

What are impairments seen with DMD?

Answer 20

1. Initial weakness occurs in the neck flexors, abdominals, interscapular, and hip extensor muscles
2. Generally, as the disease progresses weakness moves from a proximal to distal pattern
3. MMT Dynamometry can be used to predict loss of ambulation
4. Timed functional activities have been correlated with strength - 5x STS, 3/6/9 min walk test, TUG, TU from floor, gait speed

Question 21

What posture abnormalities do you see with DMD?

Answer 21

1. increased lordosis - due to ab weakness
2. compensatory winging of scap - maintains COM post to hip
3. onset of scoliosis usually just before adolescence - affects 75-90% of non-ambulatory

Question 22

Would you use an orthotic in a child with DMD?

Answer 22

Floor reaction AFO if no knee flexion contracture present

• AFO incr stress on quads
• KAFO increases energy cost, taxing CV system
• likely to lose ROM with gastroc/soleus complex first

Question 23

What are the grades for functional ability on vignos scale: UEs?

Answer 23

1 = pt can ABD arms in full circle until they touch above head
2 = pt can rain arms above head only by flexing elbow
3 = pt cannot rain hands above head but can raise 8oz glass of water to mouth
4 = pt can rain hands to mouth but not a glass
5 = pt cannot rain hands to mouth but can hold a pen or pick up pennies from table
6 = pt cannot raise hands to mouth and has no useful function of the hands

Question 24

What are the grades for functional ability on vignos scale: LEs?

Answer 24

1 = walks and climbs stairs w/o assistance
2 = walks and climbs stairs with the aid of a railing
3 = walks and climbs stairs slowly (>12s for 4 stairs) with the aid of a railing
4 = walks unassisted and rises from chair, but can't climb steps
5 = walks unassisted but cannot rise from chair or climb stairs
6 = walks with assistance or walks independently with long leg brace
7 = walks in long leg braces but requires assistance for balance
8 = stands in long leg braces but unable to walk
9 = in w/c
10 = confined to bed

Question 25

What assessment is used in DMD to indicate significant loss in of function?

Answer 25

North Star ambulatory assessment

Question 26

What kind of strengthening contraction should be avoided with DMD?

Answer 26

eccentric

Question 27

How can you predict the cessation of walking in DMD?

Answer 27

- walking ceases around 10-12 years; predicted by 50% reduction in leg strength; mmt < 3 for hip ext and < 4 DF - cessation of walking w/in 2-2.5 years when 5-12s needed to ascend 4 steps

Question 28

SMA type: onset 0-3 months, recessive inheritance; Rapid Progression, Severe Hypotonia, Death <1 year old

Answer 28

Childhood-Onset Type I Werdnig-Hoffman (Acute) | - no ambulation

Question 29

SMA type: onset 3 months - 4 years, recessive inheritance; Rapid Progression followed by stabilization, Moderate to Severe Hypotonia, Decreased Life span

Answer 29

Childhood-Onset Type II Werdnig-Hoffman (Chronic) | - no ambulation

Question 30

SMA type: onset 5-10 years, recessive inheritance; Slowly Progressive, Mild Impairment

Answer 30

Juvenile-Onset, Type III Kugelberg-Welander

Question 31

Pathophysiology: Abnormality of the large anterior horn cells in the spinal cord resulting in progressive degeneration of the remaining cells and correlated loss in function secondary to significant weakness; Diagnosis: clinical examination, laboratory testing, EMG, muscle biopsy, and genetic testing

Answer 31

Spinal musclular atrophy

Question 32

What are primary impairments of SMA?

Answer 32

1. Inconsistent cranial nerve involvement 2. Contractures - Equinovarus 3. Muscle fasciculations, especially of the tongue 4. Impaired Strength - In Types I & II: Poor head control; Delayed motor milestone achievement

Question 33

What are secondary impairments of SMA?

Answer 33

1. Scoliosis 2. Contracture 3. Decreased respiratory function

Question 34

What interventions are used for SMA?

Answer 34

1. Prevent contractures - happen a lot quicker so adaptive equipment considered sooner 2. position 3. provide adaptive equipment - start power mobility at 18 mos 4. work on strength in developmentally appropriate progressions 5. teach compensatory strategies when needed - dependent in transfers