Post Polio Syndrome Flashcards
Pathogenesis of the Polio Virus
selective destruction of the alpha motor neurons in the anterior horn; slowly progressive, new muscle weakness and fatigue with periods of stability that last 3-10 years
Post Polio Syndrome: when does it occur
a least 15 yrs after stability in polio patients, now they have an increase in symptoms (noticing weakness and fatigue in activities that did not used to bother you)
PPS and EMG
seeing giant motor units
collateral sprouting –> neighboring alpha motor neurons fiber joined motor unit (it’s unit was destroyed in the anterior horn)
PPS Symptoms (musculoskeletal)
- Fatigue and decreased endurance
- increase in skeletal deformities (scoliosis)
- Post polio progressive muscular atrophy (PPMA)- new weakness and atrophy
- Occasional pain and fasciculations (fasciculations as sign that denervation is occurring)
- new bulbar, respiratory, or sleep issues
Risk Factors
- symptoms in weakest muscles first
- in pts with most severe residual paralysis
- pts with acute poliomyelitis at an older age
How many polio survivors will end up with PPS
22-68%
Etiology hypotheses
- recovered axons are subject to premature aging and failure
- increased metabolic demands –> pruning of axon sprouts on motor units (Denervation)
- Problem at the NMJ- failure of transmission of nerve impulse
MD Dx
- clinical dx
- slightly elevated CPKs (not in 1000s like myositis)
- EMG: ongoing denervation and longstanding chronic reinnervation
Aspects important in the PT history/eval
- when did they have polio
- what was affected
- how long did it take them to recover
- type of physical activity they do and what is affected by the disease
- habitual postural analysis- figure out why there are particular MSK strains
- evaluate current orthoses and need for new ones
- MMT EVERY muscle (what to strengthen v brace)
- administer the Fatigue Severity Scale (FSS) - more sensitive than VAS
Fatigue Severity Scale: cut off for severely disabled by fatigue
> /= 50
Methods of energy conservation to teach pts
- intermittent activities
- orthotics
- changes in behavior
- weight reduction (could have been the tipping point)
Fatigue explanation
not as many alpha motor units available as before
*important to work on timing at which motor units fire
Strengthening evidence (Agre et al)
work 1 muscle at a time with submaximal, small sets
Pt’s able to produce higher torque, EMG showed increased fiber density, and CPK stabilization
Strengthening evidence of the LE (Klein et al)
groups that exercised the LEs were the only groups that showed reduction in symptoms of the UE! (leaning on the arms because the LEs are weak)
