The most common signs and symptoms of acute flaccid myelitis include: 
Sudden arm or leg weakness
Sudden loss of muscle tone
Sudden loss of reflexes
 Other possible signs and symptoms include: 
Difficulty moving the eyes or drooping eyelids
Facial droop or weakness
Difficulty with swallowing or slurred speech
Pain in the arms, legs, neck or back
 Uncommon symptoms might include: 
Numbness or tingling
Inability to pass urine
 Severe symptoms involve respiratory failure, due to the muscles involved in breathing becoming weak. It's also possible to experience life-threatening body temperature changes and blood pressure instability.