Polio and Post Polio

Pathology behind Post-polio syndrome

-onset 30-35 years after original polio -unknown cause, but several theories: ---fatigue of overworked nerve cells ---brain damage from viral infection ---weakness of PPS related to degeneration of individual nerve terminal units ---polio virus attacks specific neurons in the brainstem and spinal cord

Risk factors of Polio

-In areas with poor sanitation and sporadic or nonexistent immunization programs, the most vulnerable members of the population (pregnant women, the very young, and those with weakened immune systems) are especially susceptible to experience paralysis if they are infected with poliovirus -travel to an area where polio is common or that has recently had an outbreak -living with or caring for someone who have be shedding poliovirus -comprised immune system, such as occurs with HIV infection -having tonsils removed -extreme stress or strenuous physical activity after being exposed to poliovirus, both of which can suppress your immune system

Post-polio vs. acute onset polio

-Post-polio is non-infectious/transmittable -post-polio is characterized by muscle weakness

Three types of Paralytic Polio

-Spinal polio (most common ---affects the spine -Bulbar polio ---affects the brainstem -bulbospinal polio ---affects the spine and brainstem

Convalescent stage

-Starts 2 days after cessation of paralytic stage -continues for 2 years -spontaneous improvement of muscle power

Signs and symptoms of post-polio

-Vary greatly among individuals -slowly progressive muscle weakness -fatigue (generalized and muscular) -muscle atrophy -pain from joint degeneration -increasing skeletal deformities (such as scoliosis) -Link between symptoms: muscle pain, fatigue, deformities ---new weakness is considered the hallmark of post-polio syndrome

Causes of Polio

-direct person-to-person contact -contact with infected mucus or phlegm from nose or mouth -contact with infected feces -virus enters through mouth and nose (inevitably the stomach and intestines) ---only about 10% of cases enter through the CNS -multiplies in pharynx and gastrointestinal tract -virus invades local lymphoid tissue, enters bloodstream, and may infect cells of the CNS -replication of poliovirus in motor neurons of anterior horn and brainstem results in cell destruction and causes typical manifestations of poliomyelitis

PPS Diagnosis

-period of stability for 15+ years -prior paralytic poliomyelitis with evidence of motor neuron loss -a period of partial/complete functional recovery after acute paralytic poliomyelitis, followed by interval of stable neuromuscular function (usually 15 years) -slowly progressive and persistent new muscle weakness or decreased endurance, with or without generalized fatigue; muscle atrophy, or muscle and joint pain -symptoms persistent for at least 1 year

Subclinical infections

-the type of polio that accounts for 95% of all cases -patients may not experience any symptoms (about 95-99% of patients) -symptoms usually last for 72 hours or less and may include: ---headache, sore/red throat, slight fever, vomiting, general discomfort ---CNS not affected

Stages of Paralytic Polio

Acute, Convalescent, and Chronic

Post-Polio Syndrome

Condition that affects polio survivors after years of recovery from an initial acute attack of the poliomyelitis virus -rarely life-threatening, but symptoms can interfere with independent functioning -non-communicable -30-35 years after original polio -seen in 20-80% of surviving patients -return of: pain, fatigue, muscle weakness, functional impairment -occurs most often if: late onset, severe disease, 4 extremities, ventilator dependent, hospitalization during acute illness

Paralytic Polio

Full or partial paralysis; experience symptoms associated with non-paralytic polio first, and soon after, the following symptoms appear: -loss of reflexes; severe spasms or muscle pain; loose and floppy limb; sometimes on just one side of the body (due to weakness) -sudden paralysis that could be temporary or permanent -deformed limbs, especially hips, ankles, and feet due to prolonged weakness and lack of appropriate orthopedic training -full paralysis is rare (only about 1% of cases)

Average age of onset

It can strike at any age, but mainly affects children under 5 years old -under conditions of poor hygiene -paralysis is more common and more severe when infection occurs in older adults

Post-Polio continued

Most often, polio survivors will start to experience gradual new weakening in muscles that were previously affected by the polio infection

Chronic stage

Residual paralysis -no further recovery -limb bluish; atrophy; deformities; shortened limbs; floppy limbs; normal sensation; scoliosis or respiratory insufficiency if trunk is affected; instability

Acute stage

Variable incubation period; 1-3 weeks -reflects virus ingestion and multiplication -spinal anterior horn cell and bulbar motor nuclei involvement -onset of patchy ASYMMETRIC PARALYSIS -muscle spasms - pain -deep tendon reflexes disappear -flexor posturing (lying with curled up joints) -tender muscles -no sensory changes -reflex spasm with stretching -speech and swallowing difficulties -sudden respiratory failure -sore throat and diarrhea