Meningitis and Encephalitis Flashcards

1
Q
  • Defined as inflammation of the meninges (dura mater, arachnoid mater, and pia mater) that line the vertebral canal/skullenclosing spinal cord/brain.
  • Serious disorder caused both infectious & non-infectious etiologies.
  • Prior to the antibiotic era, was universally fatal.
  • Even with ABX therapy & imaging, condition still carries a ~ 14% mortality rate.
A

Meningitis

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2
Q

Inflammation of the brain itself

A

Encephalitis

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3
Q
  • Bacterial etiologies:
    Streptococcus Pneumonia, Group B Streptococcus, N. Meningitidis, H. influenza, E. Coli, Listeria monocytogenes
  • Viral etiologies:
    Enteroviruses (most common), coxsackieviruses, echoviruses, WNV, Influenza, HSV, VZV, EBV, arboviruses
  • Other etiologies: Fungal, Parasitic, Amebic, Non-infectious (cancers, lupus, certain meds, head injury, brain surgery).
A

Meningitis

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4
Q

Risk factors that should increase clinical suspicion:
- Close contact exposures (military barracks, college dorms)
- Incomplete vaccinations
- Immunosuppression
- > 65 y/o & < 5 y/o
- Alcohol use disorder

A

Meningitis

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5
Q

Meningitis typically occurs through two routes of inoculation:

A
  • Hematogenous seeding
    Bacteria colonize in nasopharynx & enter bloodstream. Upon making their way to the subarachnoid space, the bacteria cross the blood-brain barrier, causing a direct inflammatory and immune-mediated reaction.
  • Direct contiguous spread
    Organisms enter CSF via neighboring anatomic structures (otitis media, sinusitis) or foreign objects (medical devices, penetrating trauma).
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6
Q

In adults, evaluation is centered on:
- Identifying focal neurologic deficits
- (Brudzinski & Kernig signs)
- may have characteristic petechiae & purpura
- Cranial nerve abnormalities are seen in 10%-20% of patients.

A

Meningitis

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7
Q

Classic Meningeal Tetrad

A
  • Fever, nuchal rigidity, altered mental status, & severe headache
  • However, the presence of all four signs is not necessary for clinical diagnosis; many patients may only have 2-3 out of the 4 signs.
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8
Q

Labs for Meningitis

A

lumbar puncture with CSF analysis is always recommended

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9
Q

Imaging for meningitis

A
  • CT is the preferred imaging modality.
  • Ideally CT should be done prior to
    lumbar puncture and CSF collection.
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10
Q

Treatment of Meningitis

A

Antibiotic Treatment:
- Ceftriaxone 2g IV q12h x 7 days
- Pen-G 4 million units IV q4h x 7 days
Steroids
- dexamethasone 4mg IV

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11
Q

What should be done for meningitis with Signs of ICP (altered mental status, neurologic deficits, non-reactive pupils, bradycardia)

A

Elevating the head of the bed to 30 degrees, inducing mild hyperventilation in the intubated patient, osmotic diuretics such as 25% mannitol or 3% saline (CALL MO)

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12
Q

Chemoprophylaxis for meningitis

A
  • Ceftriaxone 250mg IM one time
  • Ciprofloxacin 500mg PO one time
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13
Q

Who is chemoprophylaxis indicated for with meningitis

A
  • Chemoprophylaxis is indicated for close contacts
  • Close contacts include:
    -housemates, significant others, those who have shared utensils, and health care providers in proximity to secretions (providing mouth-to-mouth resuscitation, intubating without a facemask).
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14
Q

Disposition for meningitis

A

Medical Evacuation is indicated for any patient with suspected meningitis, regardless of etiology or status.

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