Poliomyelitis & Post-Polio Syndrome

Question 1

Poliomyelitis

Answer 1

An acute infectious viral disease caused by poliovirus
- Enteric virus
- Main route of transmission: fecal-oral route

Question 2

Characteristics of Polio

Answer 2

• LMN syndrome - attacking anterior horn cells
• Weakness/paralysis may be “patchy” = asymmetrical
• Asymmetrical distribution
• More commonly affects LE>UE - making it difficult to walk
• Brainstem much less commonly affected as anterior horn cells

Question 3

Recovery?

Answer 3

Partial or full recovery may occur
Recovery process may last up to 2 years

Occurs in 2 ways:
1. Muscle hypertrophy
Not in the mm fibers affected but RATHER the unaffected mm will get stronger
2. Neuroplastic changes
Sprouting of neighboring terminal axons - reinnervate mm fibers from that motor (attaches to mm fibers that lost their own motor unit d/t the virus)

Question 4

Post-Polio Syndrome

Definition & Explanation

Answer 4

Poiliomyelitis symptoms reappearing adter at least ~15 years of disease stability in people who had been affected by Poiliomyelitis

Believed to be d/t NEURAL fatigue
- b/c neural units have expanded & now innervate neighboring fibers - it is getting OVERWORKED & at some point there is enough metabolic stress to cause failure
- terminal axons that sprouted will fail & potentialy the nerve body may also be affected & may potentially get INC weakness

Denervation > reinnervation
Fine balance between MSK disuse and overuse to optimize function
- INC metabloic stress = breakdown of motor unit

Question 5

Post-polio characteristics are the same as Poliomyelitis… what are they?

(6)

Answer 5

1. Slow progression. Periods of stability followed by new declines
2. LMN syndrome
3. Weakness/ paralysis may be “patchy”
4. Asymmetrical
5. More commonly affects LE > UE
6. Brainstem much less commonly affected as anterior horn cells

Question 6

S/S

(6)

Answer 6

1. Fatigue - #1 symptom & most debilitating
2. Muscle atrophy
3. Weakness
4. Pain
5. Cold intolerance
6. Breathing & swallowing disordesr if brainstem is involved

Sensory is NOT affected - sensation intact