Lecture 2: Polio and Post Polio Syndrome Flashcards
In which population is polio most common?
children under 5
Is polio contagious and if so how is it transmitted?
highly contagious, found in oral secretions and fecal matter
however 90% of infected persons are asymptomatic or have mild flu like sx
If contracted where will the virus replicate in the body?
lymphoid tissues of the throat and intestines
Can the polio virus cross the BBB?
yes but very rare only 1-2% of infections
What are risk factors for CNS involvement?
pregnancy, immune compromised, tonsillectomy
What is main pathogenesis of polio?
it is a selective attack on anterior horn cells in spinal cord or brainstem resulting in random asymmetrical spotting with LE affected more then UE
What is the result of this selected attack on the anterior horn cells?
death of neurons leads to denervated or orphaned muscles become weak and exhibit flaccid paralysis
What type of nerve is the attacked anterior horn cells?
peripheral nerves which is why it is more LMNL like
What are signs and sx of spinal poliomyelitis?
flu like, fatigue, NVD, HA, stiffness of neck and back, pain in limbs, muscle atrophy weakness and fasciculations
What are clinical sx of bulbar poliomyelitis?
weakness of muscles in thorax, abdomen and possible quadriplegia, can affect ability to breath and swallow
5-10% mortality rate due to resp failure
How can polio be medically diagnosed?
throat culture, stool sample, csf fluid
What is best form of medical management for polio?
no cure, best way to prevent is through vaccine
What medications can be used for polio to help manage symptoms?
analgesics for pain, ventilators, antibiotics for secondary infections
What is the premise behind the recovery of polio?
axon sprouting- orphaned muscles will send out chemical signals when trying to contract and nearby motor neurons will begin to adopt orphaned muscles
What is the timeline for when this axon sprouting process takes place?
begins in weeks but will plateau around 6-8 months
What happens when a motor neuron adopts and orphaned muscle group?
become super units, single motor neuron can go from innervating 100 muscles fibers to 2000
What is the danger of these new super units?
increased metabolic demand can lead to post polio syndrome
What are other possible late side effects from polio?
joint or ligament trauma, DJD, carpal tunnel, repetitive stress syndrome, tendinitis, bursitis
What percentage of patients with polio will develop post polio?
40%
What are sx of PP?
new onset of muscle atrophy and muscle weakness in muscles originally affected and others that were not, intense fatigue and pain in muscles and joints, decreased function and endurance, cold intolerance, breathing or swallowing difficulties
Why do patients with PP experience cold intolerance?
sympathetic nerve involvement and decreased vasoconstriction with heat loss
What is theory behind pathophysiology of PP?
no reactivation of virus likely due to aging and increased metabolic demand of super units
What does PP commonly develop after?
surgery, trauma, periods of inactivity and can appear to be sudden but is usually not
What is diagnostic criteria for PP?
history of polio, 15 years of functional stability, onset of two or more clinical sx, and sx have occurred for atlas 1 year
What portion of exam is extremely important for PP?
social considerations some patients may develop a survival mentality and may be afraid of returning to the stigmas they experienced before
What question is important to ask to PP pts?
are there activities that you are unable to do now that you could a few years ago
What is the goal of PT for PP pts?
reduce task demands and promote safe exercise
find balance between disuse atrophy and overwork damage
What are exercise recommendations for PP pts?
should be pain free, not increase fatigue levels, exercise muscles that can move thought full range against gravity, last rep should be as strong as first
should not inhibit next few days of ADL’s
For the unaffected muscle what is the exercise approach?
as long as they are not close to affected muscles they can exercise normally
What should be done with the involved muscles in terms of exercise?
compensatory approach, as no strength gains are expected
think of non weight bearing exercise like swimming, biking and UBE
