Acute flaccid paralysis: Difference between revisions

Latest revision as of 12:08, 1 October 2020

Background

Epidemiology

In Canada, 27 to 51 cases nationally every year
Enterovirus D68 May have a biennial pattern with peaks every 2 years

Clinical Presentation

Defined as sudden onset of muscle weakness or paralysis
- Flaccid or hypotonic, rather than hypertonic
- No other obvious cause, such as trauma
Excludes transient weakness
In acute flaccid myelitis, there are changes seen on MRI of the spinal cord

Differential Diagnosis

About half of cases in Canada are eventually diagnosed with Guillain-Barré syndrome and 20% with transverse myelitis

Guillain-Barré Syndrome and Paralytic Poliomyelitis

	Guillain-Barré syndrome	Paralytic poliomyelitis
Fever	afebrile	febrile with myalgias
Progression	subacute, days to weeks	acute, peaks at 2-4 days
Neurological deficits	ascending, symmetric muscle weakness with decreased DTRs	asymmetric weakness with increased DTRs; proximal more than distal, and legs more than arms
Sensory changes	mild disturbances or paresthesias	none
CSF findings	minimal or no pleocytosis, but elevated protein (albuminocytologic dissociation)	pleocytosis with elevated protein, normal glucose (aseptic meningitis)

Exhaustive List

Infection
- Viral
  - Picornaviridae
    - Enterovirus A71
    - Enterovirus D68
    - Coxsackievirus A7
    - Poliovirus
  - Flaviviridae: West Nile virus, Japanese encephalitis, tick-borne encephalitis
  - Herpesviridae: CMV, EBV, VZV
  - HIV-related opportunistic infections
  - Rabies
- Bacteria
Neuropathy
- Guillain-Barré syndrome, though it is typically symmetrical and bilateral ascending paralysis that may include loss of sensation
- Acute motor axonal neuropathy
- Critical illness neuropathy
- Lead poisoning
- Other heavy metal poisoning
Spinal cord
- Acute transverse myelitis
- Acute spinal cord compression
- Trauma
- Infection
Neuromuscular junction
- Myasthenia gravis
Muscle
Functional

Investigations

CBC
Imaging: CT head, MRI brain
CSF for routine, and especially for virology
Viral (especially enteroviral) PCR from CSF, nasopharyngeal swab, and/or stool
- Stool sample is sent in unpreserved, simple sterile container
- If Enterovirus PCR is positive, can request specific PCR or sequencing for poliovirus, EV D68, and EV A71

Management

All cases of acute flaccid paralysis are reportable in Ontario

@@ Line 1: / Line 1: @@
-== Differential Diagnosis ==
+== Background ==
+=== Epidemiology ===
-* Infection
-** Viral
+* In Canada, 27 to 51 cases nationally every year
-*** Other enteroviruses
+* Enterovirus D68 May have a biennial pattern with peaks every 2 years
-**** '''Enterovirus 71'''
-**** '''Enterovirus D68'''
+== Clinical Presentation ==
-**** Coxsackievirus A7
-*** Flaviviridae: '''West Nile virus''', Japanese encephalitis
+* Defined as sudden onset of muscle weakness or paralysis
-*** Herpesviridae: CMV, EBV, VZV
+** Flaccid or hypotonic, rather than hypertonic
-*** Tick-borne encephalitis
+** No other obvious cause, such as trauma
-*** HIV-related opportunistic infections
+* Excludes transient weakness
-*** Rabies
+* In acute flaccid '''myelitis''', there are changes seen on MRI of the spinal cord
-** Bacteria
-*** Borrelia
+==Differential Diagnosis==
-*** Diphtheria
-*** Botulism
+* About half of cases in Canada are eventually diagnosed with [[Guillain-Barré syndrome]] and 20% with [[transverse myelitis]]
-*** Mycoplasma
-* Neuropathy
+=== Guillain-Barré Syndrome and Paralytic Poliomyelitis ===
-** '''Guillain-Barré syndrome''', though it is typically symmetrical and bilateral ascending paralysis that may include loss of sensation
+{| class="wikitable"
-** Acute motor axonal neuropathy
+!
-** Critical illness neuropathy
+![[Guillain-Barré syndrome]]
-** Lead poisoning
+![[Poliovirus|Paralytic poliomyelitis]]
-** Other heavy metal poisoning
+|-
-* Spinal cord
+|Fever
-** Acute transverse myelitis
+|afebrile
-** Acute spinal cord compression
+|febrile with myalgias
-** Trauma
+|-
-** Infection
+|Progression
-* Neuromuscular junction
+|subacute, days to weeks
-** Myasthenia gravis
+|acute, peaks at 2-4 days
-* Muscle
+|-
-** Polymyositis
+|Neurological deficits
-** Viral myositis
+|ascending, symmetric muscle weakness with decreased DTRs
-** Post-infectious myositis
+|asymmetric weakness with increased DTRs; proximal more than distal, and legs more than arms
-** Critical illness myopathy
+|-
-* Functional
+|Sensory changes
+|mild disturbances or paresthesias
+|none
+|-
+|CSF findings
+|minimal or no pleocytosis, but elevated protein ([[albuminocytologic dissociation]])
+|pleocytosis with elevated protein, normal glucose ([[aseptic meningitis]])
+|}
+=== Exhaustive List ===
+*Infection
+**Viral
+***[[Picornaviridae]]
+****'''[[Enterovirus|Enterovirus A71]]'''
+****'''[[Enterovirus|Enterovirus D68]]'''
+****[[Enterovirus|Coxsackievirus A7]]
+****[[Poliovirus]]
+***[[Flaviviridae]]: '''[[West Nile virus]]''', [[Japanese encephalitis virus|Japanese encephalitis]], [[Tick-borne encephalitis virus|tick-borne encephalitis]]
+***[[Herpesviridae]]: [[CMV]], [[EBV]], [[VZV]]
+***[[HIV]]-related opportunistic infections
+***[[Rabies virus|Rabies]]
+**Bacteria
+***[[Borrelia burgdorferi]]
+***[[Corynebacterium diphtheriae]]
+***[[Clostridium botulinum]]
+***[[Mycoplasma pneumoniae]]
+*Neuropathy
+**'''[[Guillain-Barré syndrome]]''', though it is typically symmetrical and bilateral ascending paralysis that may include loss of sensation
+**[[Acute motor axonal neuropathy]]
+**[[Critical illness neuropathy]]
+**[[Lead poisoning]]
+**Other [[heavy metal poisoning]]
+*Spinal cord
+**[[Acute transverse myelitis]]
+**[[Acute spinal cord compression]]
+**Trauma
+**Infection
+*Neuromuscular junction
+**[[Myasthenia gravis]]
+*Muscle
+**[[Polymyositis]]
+**[[Viral myositis]]
+**[[Post-infectious myositis]]
+**[[Critical illness myopathy]]
+*Functional
+== Investigations ==
+* CBC
+* Imaging: CT head, MRI brain
+* CSF for routine, and especially for virology
+* Viral (especially enteroviral) PCR from CSF, nasopharyngeal swab, and/or stool
+** Stool sample is sent in unpreserved, simple sterile container
+** If [[Enterovirus]] PCR is positive, can request specific PCR or sequencing for [[poliovirus]], EV D68, and EV A71
+== Management ==
+* All cases of acute flaccid paralysis are reportable in Ontario
 [[Category:Neurology]]