Polio

Polio, also termed poliomyelitis, is a small RNA enterovirus transmitted by fecal-oral contamination. It is highly contagious and often remains asymptomatic. When patients are symptomatic, presentation varies but typically includes mild flu-like symptoms of fever, odynophagia, and diarrhea. A minority of cases progress to aseptic meningitis with paralysis of the extremities and respiratory musculature.

Facial paralysis is commonly associated with polio and can be an isolated finding in the disease. Large series have estimated 11% to 18% involvement of facial paralysis in polio infection (44-46). Agius in 1945 reported 426 cases of poliomyelitis in the Malta epidemic of the early 1940s and found 47 cases of facial paralysis (11%) (47). Neuropathy results from direct damage by the neurotropic polio virus. Injury to the facial nerve occurs peripherally rather than at the level of the facial nucleus.

Treatment of the systemic disease is primarily preventative. Salk developed the first vaccine against the polio virus, which was introduced in the early 1950s. The disease is now eradicated in North America, with only 250 cases reported worldwide in the first half of 2005 (17). Only physiotherapy has been studied as a treatment for facial paralysis due to polio virus and was not found to be beneficial (48).

The prognosis for facial nerve recovery is variable. Winters found roughly one-third of the patients with facial involvement had incomplete paralysis, one-third had complete paralysis but recovered to only slight weakness, and one-third had little recovery with moderate or severe facial weakness during long-term (>two years) followup (48). Moore found seven of eight patients presenting with complete facial paralysis from polio virus had some residual weakness one year or longer after illness (49). Agius found only 10 patients of 47 with facial paralysis from polio virus demonstrated persistent facial weakness on two-year followup (47).

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