BACKGROUND: @entity3328 due to the wild-type @entity9925 has been eradicated in the United States because of effective immunization programs. In the postvaccination era, most cases are caused by other RNA viruses, such as coxsackievirus or echovirus. The condition usually begins with a @entity221 and upper respiratory tract or gastrointestinal tract symptoms that progress to a "paralytic" phase characterized by @entity425 , @entity4894 , and, occasionally, @entity1576 that superficially resemble @entity5011 . OBJECTIVE: To describe 2 @entity1 with @entity3328 and highlight the findings on magnetic resonance imaging of the spinal cord to distinguish these cases from variants of @entity5011 . DESIGN AND SETTING: Case series from an academic medical center. @entity1 : Following a @entity1800 , the @entity1 , aged 35 and 50 years, had painless, progressive, asymmetrical weakness in the arms followed by @entity1576 in one @entity1 , and generalized @entity425 in the other @entity1 , reaching a nadir in 1 week. Both @entity1 had fevers but no signs of @entity693 at onset. Tendon reflexes were absent or reduced in affected regions. The cerebrospinal fluid findings were as follows: mononuclear leukocyte counts of 100 000 cells/mm(3) and 700 000 cells/mm(3), respectively, and the protein level was above 10 g/dL in both @entity1 . Compound muscle action potential amplitudes were reduced in some nerves with active denervation in clinically affected muscles, and F-responses were absent but there were no other demyelinating features. Magnetic resonance imaging showed discrete T2-weighted signal changes of the ventral horns of the spinal cord, and one had elevated coxsackievirus titers in the serum. There was little recovery and significant @entity194 in weak muscles after 3 years. CONCLUSIONS: The @entity3328 still occurs in adults in developed countries. It has superficial similarities to a motor axonal variant of @entity5011 but can be distinguished by clinical, cerebrospinal fluid, and, perhaps specifically, magnetic resonance imaging characteristics.

XXXX simulating @entity5011 .

@entity1 :: ('9606', 'Species') :: ['patients', 'patient', 'PATIENTS'] @entity3328 :: ('MESH:D011051', 'Disease') :: ['Paralytic poliomyelitis', 'nonpoliovirus poliomyelitis', 'poliomyelitis syndrome'] @entity4894 :: ('MESH:D019846', 'Disease') :: ['areflexia'] @entity9925 :: ('138950', 'Species') :: ['poliovirus'] @entity425 :: ('MESH:D018908', 'Disease') :: ['limb weakness'] @entity693 :: ('MESH:D008581', 'Disease') :: ['meningitis'] @entity1800 :: ('MESH:D014777', 'Disease') :: ['viral illness'] @entity5011 :: ('MESH:D020275', 'Disease') :: ['Guillain-Barr   syndrome'] @entity1576 :: ('MESH:D012131', 'Disease') :: ['respiratory failure'] @entity194 :: ('MESH:D001284', 'Disease') :: ['atrophy'] @entity221 :: ('MESH:D005334', 'Disease') :: ['fever']
@entity3328 :: (MESH:D011051,Disease) :: ['Nonpoliovirus poliomyelitis']
