Disorders of the Anterior Horn Cells (SMA, Postpolio Syndrome) Flashcards
(55 cards)
1
Q
SMA Type I course:
A
- Rapid
- Severe hypotonia
- Death within 3 yr
- 32% survive 2nd yr
- 8% survive 10 yrs
2
Q
Functional recovery from acute poliomyelitis:
A
- neuromuscular learning: practice
- use of muscle at a high level
3
Q
What is the age of onset of SMA Type II?
A
before 18 months
4
Q
etiology/pathology of post-polio syndrome; theories:
A
-
Unknown, but several theories:
- remaining MN can no longer maintain new sprouts; denervation exceeds reinnervation
- motor cortex with dereased capacity to control locomotor activity
- Genetic viral material deregulates immune responses
- stress of aging
- previously affected neuron did not fully recover
- metabolic exhaustion of giant motor units
- NMJ trasnmition deficits
- Scarring within motor units
- Increased weakness due to weight gain
5
Q
what gene is defective in 99% of all cases of SMA?
A
SMN 1 Survival Motor Neuron
6
Q
how many cases of pot-polio syndrome in 1987?
A
1.6 million in US
7
Q
How many of the previous acute polio pt develop post-polio syndrome
A
20-40%
8
Q
Course of SMA type III:
A
- Slowly progressive
- can ambulate at some point
- usually wheelchair dependent in adulthood
- shortened lifespan
- some may have normal lifespan
9
Q
What is survival motor neuron SMN1?
A
naturally occuring protein
10
Q
AHC degeneration leads to
A
progressive muscle weakness & atrophy
11
Q
What is the course SMA type II?
A
- Can survivie up to 10 yrs
- Progressive but stabilizes
- Can sit, but standing or walking usually not possible
12
Q
What is poliomyelitis?
A
- Poliovirus spreads to CNS & attacks motor neurons in spinal cord & brain
- Results in assymmetric flaccid muscle paresis or paralysis
- LE’s more affected than UE’s
13
Q
A 1 y/o child has been diagnosed with SMA. What is the prognosis?
A
will lose ambulatory ability at around age 12
14
Q
Gene deletion of chromosome 5
A
SMA
15
Q
Clinical course of postpolio syndrome
A
- Normal
- Paralysis
- Recovery
- 10-15 yrs of stability
- Post-polio syndrome
16
Q
prognosis of SMA
A
- best prognosis types III and IV
- type III:
- Onset > 2 yrs old; remain ambulatory during adulthood
- Onset before 2 yrs: lose ambulatory ability at age 12 on
average
17
Q
SMA P.T. Intervention may include:
A
– Strengthening exercises
– Aerobic exercise
– Developmental skill training
– Aquatic therapy
– Standing program
– Management of respiratory complications
– Management of contractures
– Management of scoliosis/skeletal deformities
– Prescription of/training with assistive devices
18
Q
Medical treatment of SMA:
A
- Symptomatic and preventive, no cure
- Respiratory care
- prevent MSK complications
- Maintenance of head control
- feeding assitance
- scoliosis tx
19
Q
What are the clinical features of SMA type III?
A
- Prox LE weakness
- Good UE strenght
- Slow, continued developmental progression
- Can sit inddependently
- Gait and postural deviations
20
Q
What is post-polio syndrome?
A
- In 70’s and 80’s polio survivors developed new weakness
- Late effects of polimyelitis
- primary, secondary, MSK and psychosocial impairments
21
Q
Psychological considerations of PPS:
A
- Coping Styles
- Response to new diagnosis
- Compliance
22
Q
percentage of people infected with polio virus that do not develop illness or only mild case:
A
95-99%
23
Q
How are the EMG/NVC in PPS?
A
- Sensory NCV: normal
- Motor NCV: normal but may be slowed
- EMG: abnormalities of chronic denervation
- Muscle biopsy
24
Q
When does the onset of SMA occur?
A
- varies from early onset to late in life
- majority occur during infancy
- adult forms are very rare
25
Clinical features of SMA type IV:
* mild to moderate gradual proximal muscle weakness
* may show tremor and twitching, mild respiratory difficulty
* usually remain ambulatory, may need wheelchair
* normal lifespan
26
What is the adopted posture in children with SMA type I?
* LE: flexed, abbducted, externally rotated
* UE: abducted externally rotated, unable to move to midline against gravity
27
PPS clinical manifestations:
* Fatigue: most common symptom
* New muscle weakness: asymmetric. prox. and/or distal.
* Due to disuse, overuse, chronic, weight gain
* Muscle atrophy
* Muscle pain: high intensity, associated with mechanical stress
* Swallowing dysfunction
* Gait and difficulty with ADL's
* Respiratory dysfunction
* Cold intolerance
* Sleep disorders
28
A group of inherited disorders characterized by degeneration and loss of anterior horn cells (AHC)
**SPINAL MUSCULAR ATROPHY (SMA)**
29
Neurological recovery from acute poliomyelitis affected by:
1. Motor neurons that recover & resume normal fucntion
2. Collateral sprouting to reinnervate orphaned muscle fibers: giant motor units
3. Innervated muscle fibers can be hypertrophied by intensive exercise: denervation hypertrophy
30
Onset of post-polio syndrome
35 yrs after acute polio
31
What is the adopted posture in children with SMA type II?
**LE** flexed, abb, ER
32
onset of SMA type IV
after age 30
33
in the eraly polio epimic, patient were told to...
* Use "heroic" compensatory methods
* used ligaments for stability (resulted in hypermobility)
34
How is the weakness presented in SMA?
* Bilateral
* Symetrical
* More proximal
* Facial muscles may be involved
* Relative sparing of eye muscles and anal sphincter
35
onset of SMA type I
0-3 months
36
What is the inicidence of SMA type I, II, III?
* Type I: 1 in 15,000 - 25,000 live births
* Type II: 1 in 15,000 - 25,000 live births
* Type III: 6 in 100,000 live births
37
Diferential diagnosis of PPS need to rule out:
* ALS
* MS
* Hypothyroid myopathy
* Other conditions:
* Anemia
* Chronic infection
* Infectious myopathy
* Myasthenia gravis
* Weakness due to aging
* Weight gain
38
A 3 y/o child has been diagnosed with SMA. What is the prognosis?
remain ambulatory during adulthood
39
diagnosis of SMA
* Clinical pictures
* muscle biopsy
* decreased motor AP in **EMG**
* **NCV:** slower later in the course
* **Genetic testing**
40
What is the long term effect of substitutions and overcompesations?
* Microtrauma of ligaments and joint structures
* Exhaustion of neuromuscular units
## Footnote
*(Poliomyelitis)*
41
Second most common fatal autosomal recessive disorder after cystic fibrosis
**SMA**, mother and father has to have it
42
What do lab tests in PPS show?
**elevated creatine kinase**
## Footnote
*Clinically, creatine kinase is assayed in blood tests as a marker of damage of CK-rich tissue such as in myocardial infarction (heart attack), rhabdomyolysis (severe muscle breakdown), muscular dystrophy, the autoimmune myositides and inacute renal failure.*
43
Common SMA deformities include:
* Scoliosis
* Kyphosis
* Lordosis
* Contractures
* Joint dislocation
44
Incidence of SMA type I
**1 in 15,000 - 25,000** live births
45
General picture of SMA:
* Bilateral, symmetric, proximal weakness
* Skeletal deformities
* Progressive atrophy: flaccidity
* Dimished DTR's
* Normal sensory
* Normal intellectual
* Restrictive lung disease
46
Severity of signs and symptoms in SMA related to what?
* how many copies of SMN2 are present
* More copies of SMN2 = more SMN protein produced = less severe forms of SMA
47
Diagnosis of PPS:
* Hx of polio
* 15 yrs of stability
* At least two new symptoms from the following:
* Excessive fatigue
* Muscle or joint pain
* Muscle atrophy
* Cold intolerance
* **Rule out:** ALS, MS, hypothyroid myopathy, MG, weight gain, wekaness due to aging
48
Rehab considarations for muscle and joint pain in PPS:
* Heat
* Electrical stimulation
* Stretching exercises/ROM
* Muscle relaxation exercise
* Biofeedback
* Lifestyle changes
49
Types of SMA?
* SMA I
* SMA II
* SMA III
* Adult SMA (IV)
50
What is the age of onset of SMA type III?
18 months
51
SMA prevalence:
* 1 in 20,000 live births
* 1 in 50 carry the genetic defect
52
SMA goals for PT
* Achieve highest levels of indepence and mobility
* improve/maintain muscle strenght and aerobic capacity
* prevent or delay development of complications
53
SMA Pathogenesis
* AHC degenration occurs due to decreased level of SMN1
* SMN2 can compensate, but is not as effective.
54
Which is the most severe form of SMA?
SMA Type I
55
