CNS Infections

Question 1

3 routes of CNS infection

Answer 1

Hematogenous:Most of community-onset bacterial CNS infections
Contiguous:Direct extension from neighboring anatomical sites
Ascending:Direct extension from peripheral nervous system

Question 2

T/F: Ascending route of infection is usually caused by bacteria.

Answer 2

False.Usually caused by virus

Question 3

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

Answer 3

D.N. meningitidis is encapsulated and surive in the blood stream.

Question 4

Kernig’s sign

Answer 4

pain behind knee and resistance when extending knee

Sign of meningeal irritation

Question 5

Brudzinski’s sign

Answer 5

neck flexion elicits leg flexion

Sign of meningeal irritation

Question 6

T/F: Kernig/Brudzinski sign has high sensitivity, low specifity.

Answer 6

False. Jolt accentuation hashigh sensitivity, low specificity.
Kernig/Brudzinski sign has low sensitivity, high specifity.

Question 7

Most important diagnostic test for meningitis

Answer 7

Lumbar puncture

Question 8

Papilledema is a sign of

Answer 8

elevated intracranial pressure

Question 9

What are the contraindications of doing an LP? (4)

Answer 9

Intracranial mass lesion
Intracranial hypertension
Severe thrombocytopenia or coagulopathy
Agitated pt

Question 10

T/F:NEVER delay administration of abx for possible bacterial meningitis by attempting to safely perform a LP

Answer 10

True.

Always try to initiate abx therapy ASAP

Question 11

T/F: CT is good to diagnose CNS pathology and confirm a diagnosis of meningitis.

Answer 11

False. CT only good to check for LP safety

MRI demonstrates CNS pathology

Question 12

T/F: Bacterial meningitis is a medical emergency.

Answer 12

TRUE!If you got this wrong, you will be punched in the face. You’ve been warned.

Question 13

Classic triad of symptoms for meningitis

Answer 13

Fever
Nuchal rigidity
Altered mental status

1/3 have all 3
>95% have at least 2

Question 14

Which of the following is NOT a CSF finding of bacterialmeningitis?
A. Low glucose
B. High neutrophils
C. High mononuclear cells

Answer 14

C

Question 15

Which of the following is NOT a CSF finding of tuberculousmeningitis?
A. Low glucose
B. High neutrophils
C. High mononuclear cells

Answer 15

B

Question 16

Which of the following is NOT a CSF finding of viral meningitis?
A. Low glucose
B. High neutrophils
C. High mononuclear cells

Answer 16

A. Normal glucose
AND
B. High neutrophils

Question 17

Bacterial or viral meningitis?

Rapid progression

Answer 17

Bacterial

Question 18

Bacterial or viral meningitis?

Seasonality: more in summer

Answer 18

Viral

Question 19

Bacterial or viral meningitis?

Could be caused by head trauma/neurosurgery

Answer 19

Bacterial

Question 20

Bacterial or viral meningitis?

Could be outdoor exposure/travel

Answer 20

Viral

Question 21

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?

Answer 21

C. Treat with:
Ampicillin+
(3rd gen cephalosporinOR aminoglycoside)

Question 22

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?

Answer 22

D

Treat w/:
Vancomycin + 3rd gen cephalosporin

Question 23

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?

Answer 23

A and B

Treatment:
Vancomycin + 3rd gen cephalosporin

Question 24

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?

Answer 24

A

Treat w/:
Vancomycin + 3rd cen cephalosporin + ampicillin

Question 25

T/F: Neck stiffness is a common symptom of encephalitis.

Answer 25

False. Less common than in menengitis
Symptoms:
Focal neurologic signs
Altered mental status

Question 26

T/F:Suspect menengitisfor any unexplained brain parenchymal lesion

Answer 26

False.Suspect encephalitis for any unexplained brain parenchymal lesion

Question 27

Which of the following is NOT a symptom of HSV Encephalitis?
A. Fever
B. Personality changes
C. Seizures
D. Syncopy
E. Motor deficit

Answer 27

D

Question 28

How to diagnose HSV Encephalitis?

Answer 28

HSV PCR on CSF

VERY sensitive and specific = gold standard for diagnosis

Question 29

Treatment of HSV encephalitis?

Answer 29

High dose acyclovir (10 mg/kg IV q 8 hours)

Question 30

T/F: You should wait for test resuts to confirm HSV encephalitis before starting Acyclovir to ensure efficacy of treatment.

Answer 30

False.ASSUME HSV encephalitis in pts with encephalitis until proven otherwise.
Start Acyclovir immediately. Do NOT wait for test results.

Question 31

Treatment of brain abcesses caused by otitis media/sinusitis, dental/odontogenic

Answer 31

Ceftriaxone + Metronidazole

Question 32

Treatment of brain abcsesses caused by penetrating trauma, post op, or unknown source

Answer 32

Vancomycin + Ceftriaxone + Metronidazole