people who had recovered from childhood
poliomyelitis. Though researchers do not fully
understand what causes postpolio syndrome, it
appears to result from damage the poliovirus
caused to motor neurons during the active infec-
tion rather than a recurrent or new poliomyelitis
infection. About one in four people who recover
from paralytic poliomyelitis develops postpolio
syndrome 10 to 40 years later.
Symptoms and Diagnostic Path
Subclinical poliomyelitis is a very mild infection
that does not cause symptoms. The symptoms of
nonparalytic poliomyelitis are similar to those of
influenza and include
- NAUSEA, VOMITING, andDIARRHEA
- moderate FEVER
- muscle aches and weakness
- extreme fatigue
- irritability
- muscle aches in the lower back and calves
- painful SKIN RASH
The course of nonparalytic illness runs about
two weeks, during which symptoms gradually
subside. The symptoms of paralytic poliomyelitis
are far more severe and are similar to those of
MENINGITISor ENCEPHALITIS. They include
- moderate to high fever
- stiffness and pain in the neck and upper back
- HEADACHE
- rapid onset of muscle weakness that may
progress to paralysis within hours- muscle PAINand cramping throughout the body
- extreme irritability
The diagnostic path begins with a PERSONAL
HEALTH HISTORYto determine the likelihood and cir-
cumstances of exposure to the poliovirus. The
presence of poliovirus in CEREBROSPINAL FLUID
obtained via LUMBAR PUNCTUREconfirms the diag-
nosis.Treatment Options and Outlook
Treatment is supportive while the infection runs
its course, which is typically two to three weeks.
Such support may include medications to relieve
muscle SPASMand pain, improve gastrointestinal
and urinary function, and treat secondary bacter-
ial infections (commonly affecting the urinary
tract and the upper respiratory tract). Paralysis
that affects breathing may require MECHANICAL VEN-
TILATION.
Most people who survive the course of the dis-
ease recover, though many have residual complica-
tions such as partial paralysis or muscle deformities
that result from the extensive damage to motor
neurons. When damage is high in the spinal cord,
the person may experience continued difficulty
breathing or relatively complete paralysis.Risk Factors and Preventive Measures
Vaccination prevents infection with the poliovirus;
poliomyelitis occurs only in people who have not
received proper vaccination or who received vac-
cination in childhood and travel in later adulthood
to parts of the world where poliomyelitis remains
endemic (notably Africa and Southeast Asia).
See also INCUBATION PERIOD; PREVENTIVE HEALTH
CARE AND IMMUNIZATIONS.278 The Nervous System