- Infectious etiology-selective damage to anterior horn cells after setting of febrile illness.
- Member of Picornavirdae family of RNA virus
- Poliovirus type I is most frequent cause of illness, spread person to person.
Post Polio Syndrome
- Increased weakness
- Respiratory dysfunction
- Swallowing dysfunction
- Age related motor loss of motor neurons-greater weakness than expected due to reduced margin of safety.
- Premature aging of normal or partially damaged neurons-surviving motor neurons unable to maintain cellular function over time.
- Chronic poliovirus infection
- Increased susceptibility of motor units to other insults.
- 25-30 % patients with history of polio develop symptoms.