Poliomyelitis

Question 1

Main points

Answer 1

poliovirus, a type of human Enterovirus (Picornaviridae)
IP 7-14d
spreads via fecal-oral transmission
Usually asymptomatic
Flu-like symptoms (ABORTIVE POLIOMYELITIS)
In rare cases, patients develop paralytic poliomyelitis, which manifests with weakness, decreased muscle tone, and hyporeflexia.
PCR RNA in body fluids
has been eradicated in most parts of the world as a result of global vaccination initiatives.

less than 1% of infected individuals develop paralysis

Question 2

Pathophysio

Answer 2

The virus replicates in the gastrointestinal tract (oropharynx and small intestine) following oral ingestion → enters the bloodstream → potential invasion of the gray matter of the spinal cord (particularly the lower motor neurons of the anterior horn) → myelitis

Question 3

TYPES

Answer 3

1. W/o CNS involvement: Abortive (poronny)~flu
2. With CNS involvement
   -Nonparalytic poliomyelitis: aseptic meningitic form
   Begins several days following abortive
   -> Neck muscle weakness (head drop sign: head falls back when placed in a supine position); No paresis

-Paralytic
Occurs 2–3 days following the meningitic form after a brief symptom-free interval

Question 4

Paralytic form - symptoms

Answer 4

Fever, malaise, headache, nausea
Severe back, neck, and muscle pain
Asymmetric acute flaccid paralysis worsens over hours to days.Most commonly affects the leg muscles, more severe in proximal muscles

Ascending paralysis with diaphragmatic involvement → respiratory failure

Bulbar form with brain stem involvement (rare): damage to the cerebral or autonomic nerve centers (cranial nerves and respiratory center) → central respiratory paralysis
Diminished deep tendon reflexes
Muscle atrophy
Hypotonia
Fasciculations

Question 5

Post-polio syndrome (PPS)

Answer 5

Most frequent complication, occurs after decades after inf,
Manifests with progressive muscle weakness and pain,

Question 6

CSF

Answer 6

High protein levels
Pleocytosis with either neutrophils (early infection) or lymphocytes (late infection)
Normal glucose levels

Question 7

Diff dx

Answer 7

Guillain-Barré syndrome: Paralysis is typically symmetrical in Guillain-Barré syndrome. In addition, it would not manifest with CSF pleocytosis.
Acute intermittent porphyria: may also present with muscle weakness and bulbar paralysis
Spinal muscular atrophy: Paralysis is typically symmetrical.

Question 8

Tx

Answer 8

Symptomatic

Airway management and mechanical ventilation if needed