Lecture 2: Polio and Post Polio Syndrome

Question 1

In which population is polio most common?

Answer 1

children under 5

Question 2

Is polio contagious and if so how is it transmitted?

Answer 2

highly contagious, found in oral secretions and fecal matter

however 90% of infected persons are asymptomatic or have mild flu like sx

Question 3

If contracted where will the virus replicate in the body?

Answer 3

lymphoid tissues of the throat and intestines

Question 4

Can the polio virus cross the BBB?

Answer 4

yes but very rare only 1-2% of infections

Question 5

What are risk factors for CNS involvement?

Answer 5

pregnancy, immune compromised, tonsillectomy

Question 6

What is main pathogenesis of polio?

Answer 6

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

Question 7

What is the result of this selected attack on the anterior horn cells?

Answer 7

death of neurons leads to denervated or orphaned muscles become weak and exhibit flaccid paralysis

Question 8

What type of nerve is the attacked anterior horn cells?

Answer 8

peripheral nerves which is why it is more LMNL like

Question 9

What are signs and sx of spinal poliomyelitis?

Answer 9

flu like, fatigue, NVD, HA, stiffness of neck and back, pain in limbs, muscle atrophy weakness and fasciculations

Question 10

What are clinical sx of bulbar poliomyelitis?

Answer 10

weakness of muscles in thorax, abdomen and possible quadriplegia, can affect ability to breath and swallow

5-10% mortality rate due to resp failure

Question 11

How can polio be medically diagnosed?

Answer 11

throat culture, stool sample, csf fluid

Question 12

What is best form of medical management for polio?

Answer 12

no cure, best way to prevent is through vaccine

Question 13

What medications can be used for polio to help manage symptoms?

Answer 13

analgesics for pain, ventilators, antibiotics for secondary infections

Question 14

What is the premise behind the recovery of polio?

Answer 14

axon sprouting- orphaned muscles will send out chemical signals when trying to contract and nearby motor neurons will begin to adopt orphaned muscles

Question 15

What is the timeline for when this axon sprouting process takes place?

Answer 15

begins in weeks but will plateau around 6-8 months

Question 16

What happens when a motor neuron adopts and orphaned muscle group?

Answer 16

become super units, single motor neuron can go from innervating 100 muscles fibers to 2000

Question 17

What is the danger of these new super units?

Answer 17

increased metabolic demand can lead to post polio syndrome

Question 18

What are other possible late side effects from polio?

Answer 18

joint or ligament trauma, DJD, carpal tunnel, repetitive stress syndrome, tendinitis, bursitis

Question 19

What percentage of patients with polio will develop post polio?

Answer 19

40%

Question 20

What are sx of PP?

Answer 20

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

Question 21

Why do patients with PP experience cold intolerance?

Answer 21

sympathetic nerve involvement and decreased vasoconstriction with heat loss

Question 22

What is theory behind pathophysiology of PP?

Answer 22

no reactivation of virus likely due to aging and increased metabolic demand of super units

Question 23

What does PP commonly develop after?

Answer 23

surgery, trauma, periods of inactivity and can appear to be sudden but is usually not

Question 24

What is diagnostic criteria for PP?

Answer 24

history of polio, 15 years of functional stability, onset of two or more clinical sx, and sx have occurred for atlas 1 year

Question 25

What portion of exam is extremely important for PP?

Answer 25

social considerations some patients may develop a survival mentality and may be afraid of returning to the stigmas they experienced before

Question 26

What question is important to ask to PP pts?

Answer 26

are there activities that you are unable to do now that you could a few years ago

Question 27

What is the goal of PT for PP pts?

Answer 27

reduce task demands and promote safe exercise

find balance between disuse atrophy and overwork damage

Question 28

What are exercise recommendations for PP pts?

Answer 28

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

Question 29

For the unaffected muscle what is the exercise approach?

Answer 29

as long as they are not close to affected muscles they can exercise normally

Question 30

What should be done with the involved muscles in terms of exercise?

Answer 30

compensatory approach, as no strength gains are expected

think of non weight bearing exercise like swimming, biking and UBE