CNS Infections Flashcards
3 routes of CNS infection
Hematogenous:Most of community-onset bacterial CNS infections
Contiguous:Direct extension from neighboring anatomical sites
Ascending:Direct extension from peripheral nervous system
T/F: Ascending route of infection is usually caused by bacteria.
False.Usually caused by virus
Which of the following is NOT an organism involved as asystemic infectionof the CNS? A.Staph aureus B. Group B strep C.Mycobacterium tuberculosis D.N. meningitidis
D.N. meningitidis is encapsulated and surive in the blood stream.
Kernig’s sign
pain behind knee and resistance when extending knee
Sign of meningeal irritation
Brudzinski’s sign
neck flexion elicits leg flexion
Sign of meningeal irritation
T/F: Kernig/Brudzinski sign has high sensitivity, low specifity.
False. Jolt accentuation hashigh sensitivity, low specificity.
Kernig/Brudzinski sign has low sensitivity, high specifity.
Most important diagnostic test for meningitis
Lumbar puncture
Papilledema is a sign of
elevated intracranial pressure
What are the contraindications of doing an LP? (4)
Intracranial mass lesion
Intracranial hypertension
Severe thrombocytopenia or coagulopathy
Agitated pt
T/F:NEVER delay administration of abx for possible bacterial meningitis by attempting to safely perform a LP
True.
Always try to initiate abx therapy ASAP
T/F: CT is good to diagnose CNS pathology and confirm a diagnosis of meningitis.
False. CT only good to check for LP safety
MRI demonstrates CNS pathology
T/F: Bacterial meningitis is a medical emergency.
TRUE!If you got this wrong, you will be punched in the face. You’ve been warned.
Classic triad of symptoms for meningitis
Fever
Nuchal rigidity
Altered mental status
1/3 have all 3
>95% have at least 2
Which of the following is NOT a CSF finding of bacterialmeningitis?
A. Low glucose
B. High neutrophils
C. High mononuclear cells
C
Which of the following is NOT a CSF finding of tuberculousmeningitis?
A. Low glucose
B. High neutrophils
C. High mononuclear cells
B
Which of the following is NOT a CSF finding of viral meningitis?
A. Low glucose
B. High neutrophils
C. High mononuclear cells
A. Normal glucose
AND
B. High neutrophils
Bacterial or viral meningitis?
Rapid progression
Bacterial
Bacterial or viral meningitis?
Seasonality: more in summer
Viral
Bacterial or viral meningitis?
Could be caused by head trauma/neurosurgery
Bacterial
Bacterial or viral meningitis?
Could be outdoor exposure/travel
Viral
Which of the following is NOT a possible organism to cause meningitis in someone less than 1 month old? A. Group B Strep B. Listeria monocytogenes C. Haemophilus influenzae D. E. Coli
Treatment?
C. Treat with:
Ampicillin+
(3rd gen cephalosporinOR aminoglycoside)
Which of the following is NOT a possible organism to cause meningitis in someone 1-23month y/o? A. Group B Strep B. E. coli C. Haemophilus influenzae D. Listeria monocytogenes E. Strep pneumoniae F. Neisseria meningitidis
Treatment?
D
Treat w/:
Vancomycin + 3rd gen cephalosporin
Which of the following is NOT a possible organism to cause meningitis in someone 2-50 y/o? A. Group B Strep B. E. coli C. Strep pneumoniae D. Neisseria meningitidis
Treatment?
A and B
Treatment:
Vancomycin + 3rd gen cephalosporin
Which of the following is NOT a possible organism to cause meningitis in someone >50 y/o? A. Group B Strep B. Anerobic gram-negative bacilli C. Listeria monocytogenes D. Strep pneumoniae E. Neisseria meningitidis
Treatment?
A
Treat w/:
Vancomycin + 3rd cen cephalosporin + ampicillin
T/F: Neck stiffness is a common symptom of encephalitis.
False. Less common than in menengitis
Symptoms:
Focal neurologic signs
Altered mental status
T/F:Suspect menengitisfor any unexplained brain parenchymal lesion
False.Suspect encephalitis for any unexplained brain parenchymal lesion
Which of the following is NOT a symptom of HSV Encephalitis? A. Fever B. Personality changes C. Seizures D. Syncopy E. Motor deficit
D
How to diagnose HSV Encephalitis?
HSV PCR on CSF
VERY sensitive and specific = gold standard for diagnosis
Treatment of HSV encephalitis?
High dose acyclovir (10 mg/kg IV q 8 hours)
T/F: You should wait for test resuts to confirm HSV encephalitis before starting Acyclovir to ensure efficacy of treatment.
False.ASSUME HSV encephalitis in pts with encephalitis until proven otherwise.
Start Acyclovir immediately. Do NOT wait for test results.
Treatment of brain abcesses caused by otitis media/sinusitis, dental/odontogenic
Ceftriaxone + Metronidazole
Treatment of brain abcsesses caused by penetrating trauma, post op, or unknown source
Vancomycin + Ceftriaxone + Metronidazole
