Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PBR: Infectious Disease > CNS Infections > Flashcards

CNS Infections Flashcards

1
Q

Which organisms are the most common cause of meningitis in a neonate?

A

Group B Strep, E. Coli, and Listeria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which organisms are the most common cause of meningitis in a 6 year old?

A

Streptococcus pneumoniae (applies to children ?3 months to 10 years of age)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which organisms are the most common cause of meningitis in a 17 year old?

A

N. meningitidis (applies to children 10 years - 19 years of age)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

In which patient populations should you consider Listeria as a potential etiologic agent for bacterial meningitis?

A

Infants, organ transplant recipients, patients with immunodeficiency, and patients >60 years of age.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which antibiotics do not cross into the CSF and should never be used to provide CNS coverage?

A

Erythromycin, tetracycline, clindamycin, 1st and 2nd generation cephalosporins, and aminoglycosides (however, gentamicin is used synergistically in some regimens; e.g treatment of Listeria or enterococcus meningitis).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the empiric treatment for meningitis in infants >3 months of age?

A

3rd generation cephalosporin (Ceftriaxone or Cefotaxime) + Vancomycin (to cover for resistant S. pneumoniae)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the empiric treatment for meningitis in infants <3 months of age?

A

3rd generation cephalosporin (Ceftriaxone, Cefotaxime, or Ceftazidime) + Vancomycin (to cover for resistant S. pneumoniae) + Ampicillin (to cover for Listeria)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why should Ceftazidime or Cefotaxime be used in place of Ceftriaxone in the empiric management for meningitis in infants <1 month old?

A

Ceftriaxone can displace bilirubin from albumin binding sites in neonates, theoretically putting them at risk for the development of acute bilirubin encephalopathy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What should be added to the empiric antibiotic therapy regimen if pneumococcal meningitis is suspected?

A

Vancomycin should be added to the 3rd generation cephalosporin due to the possibility of cefalosporin-resistant S. pneumoniae. Rifampin can be used in place of vancomycin if the patient is allergic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What would one expect to see on gram stain for a patient with an infection caused by S. pneumo?

A

Gram-positive cocci in pairs and chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

When are glucocorticoids approved for use in meningitis?

A

They are approved for use in patients with H. influenzae meningitis to reduce neurologic complications (including hearing loss). They are most effective if started prior to or concurrent with the first dose of antibiotics.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

In which types of meningitis should close contacts receive chemoprophylaxis?

A

Close contacts of patients with meningococcal meningitis and Hib meningitis should receive prophylaxis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the preferred treatment regimen for patients with confirmed meningococcal meningitis?

A

High-dose penicillin if susceptible, or 3rd generation cephalosporin if patient is PCN allergic. Close contacts should receive prophylaxis as well.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the definition of aseptic meningitis?

A

Headache, meningismus, and CSF lymphocytosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the common CSF findings associated with aseptic meningitis?

A

Normal/elevated opening pressure, WBC 10-1,000 cells/uL with lymphocyte predominance, and protein and glucose levels either normal or slightly elevated.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

List the most common viral etiologies associated with aseptic meningitis and the typical time of year associated with the highest prevalance of each.

A

Enteroviruses and arboviruses in summer/early fall, mumps in the spring, HSV any time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

If a patient from the arid Southwest presents with meningitis, what endemic pathogen should be on your differential?

A

Coccidioides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

If a patient from the Mississippi/Ohio river valleys presents with meningitis, what endemic pathogen should be on your differential?

A

Histoplasma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

In adolescent patients with ALL, AIDS, or Hodgkin disease who present with meningitis, what uncommon pathogen should be added to the differential and what additional laboratory testing should be performed?

A

Cryptococcus. Do a CSF cryptococcal antigen and/or India ink test.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

If a patient presents with meningitis and has recently been swimming in warm, unchlorinated water in the South in late summer, what pathogen should be suspected first?

A

Amebic meningitis should be suspected (Naegleria fowleri).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What pathogens should be considered in patients presenting with chronic neutrophilic meningitis?

A

Nocardia, Actinomyces, or fungi.

22
Q

What CT finding is classic for tuberculous meningitis?

A

Basilar enhancement. (This finding can also be seen in infections caused by spirochetes, i.e. secondary syphilis and Lyme disease).

23
Q

What cranial nerve palsy can sometimes be seen in tuberculous meningitis?

A

CN 6 palsy (presents with double vision and strabismus)

24
Q

What are the typical CSF findings in tuberculous meningitis?

A

Mild-to-moderate WBC elevation with monocytic predominance, very high protein, and low glucose. Opening pressures are typically very high and are often not measurable with a standard manometer.

25
Q

What is the classic presentation for Lyme meningitis?

A

Indolent onset of lymphocytic meningitis with a cranial nerve palsy (typically CN7 - facial). Spinal nerve roots can also be involved, so think of Lyme when a patient presents with Bell’s palsy and/or foot drop with suggestive exposure history.

26
Q

What is the recommended treatment regimen for Lyme meningitis?

A

Ceftriaxone for 21 days.

27
Q

Which virus causes the most deaths in acute encephalitis?

A

HSV. HSV-1 and HSV-2, taken together, are the singal most common cause of infectious encephalitis in the U.S.

28
Q

If a patient has been diagnosed with infectious encephalitis, what specific pathogen should come to mind for a patient with focal seizures or MRI findings localized to the temporal lobes?

A

HSV. The CSF may also be bloody due to hemorrhagic necrosis of the temporal lobes.

29
Q

In a patient diagnosed with encephalitis, what etiology should be suspected for patients with a history of psychiatric symptoms early in the course of the illness?

A

Autoimmune encephalitis.

30
Q

What is the most common pathogen associated with the presence of a spinal epidural abscess?

A

S. aureus

31
Q

What is the preferred empiric antibiotic regimen for spinal epidural abscesses?

A

Vancomycin + 3rd/4th generation cephalosporin

32
Q

What is a common cause for spinal epidural abscess formation worldwide that is not as common in the U.S.?

A

TB

33
Q

What pathogens should come to mind if a patient has a brain abscess localized to the frontal lobe?

A

Think paranasal sinuses: Pneumococcus, H. influenzae, and anaerobes.

34
Q

What pathogens should come to mind if a patient has a brain abscess localized to the temporal lobe or cerebellum?

A

Think middle ear: Pneumococcus, H. influenzae, S. aureus, and gram negatives.

35
Q

What is the suggested empiric management of a brain abscess when the source is uncertain?

A

Vancomycin, Cefotaxime, and Metronidazole.

36
Q

What is the suggested empiric management of a brain abscess when an oral source is certain?

A

High dose Penicillin G + Metronidazole.

37
Q

What is the suggested empiric management of a brain abscess when an ear or sinus source is suspected?

A

Ceftriaxone/Cefotaxime + Metronidazole.

38
Q

What is the suggested empiric management of a brain abscess when there has been a penetrating head trauma or acute endocarditis?

A

In these situations, MRSA should be accounted for, so Vancomycin should be used in conjunction with a 3rd generation cephalosporin and Metronidazole.

39
Q

What is the suggested empiric management of a brain abscess which occurs following a neurosurgical procedure?

A

In this situation, MRSA and Pseudomonas should be considered. Use vancomycin + Meropenem or Cefepime.

40
Q

Which pathogens are likely to cause brain abscesses in neonates with meningitis and should prompt an urgent contrasted CT head or MRI if isolated from blood or CSF?

A

Citrobacter koseri, Serratia marcescens, Proteus mirabilis, and Cronobacter sakazakii.

41
Q

What is the most common cause of brain lesions in developing countries?

A

Cysticercosis (caused by ingesting the pork tapeworm T. solium).

42
Q

What diagnosis should come to mind for this presentation: a teenager from Mexico comes in with new-onset seizures and a ring-enhancing lesion on CT scan.

A

Neurocysticercosis

43
Q

What is the most likely etiologic agent for brain abscess if the patient is immunodeficient?

A

Toxoplasma. This is even more likely if there are several lesions noted on imaging. Infection is usually due to a reactivation of dormant cysts.

44
Q

What pathogen is a rare cause for neutrophilic aseptic meningitis?

A

Nocardia

45
Q

Describe the Kernig sign.

A

With the patient flat on their back, flex the thigh so that it is at a right angle to the trunk, then completely extend the leg at the knee joint. If the leg cannot be completely extended due to pain it is considered a positive Kernig sign and is indicative of meningeal irritation.

46
Q

Describe the Brudzinski sign.

A

With the patient flat on their back, gently flex the neck, bringing chin to chest. If the patient involuntarily flexes the hips and knees, this is considered to be a positive Brudzinski sign and is indicative of meningeal irritation.

47
Q

What is the gold standard for diagnosis of bacterial meningitis?

A

CSF culture

48
Q

Which CSF studies should be performed in patients for whom meningitis is suspected? (What study do we often send that may not be tested on boards?)

A

Gram stain, CSF culture with sensitivities, cell count with differential, CSF protein, and CSF glucose. (We often send the rapid meningitis panel PCR test as well).

49
Q

What are the classic CSF findings in patients with bacterial meningitis?

A

WBC >1,000 WBC/uL with neutrophil predominance, glucose <40 mg/dL, and protein >100 mg/dL.

50
Q

In which situations should a CT be performed prior to attempting a lumbar puncture?

A

Coma, recent CNS trauma, focal neurologic deficit, papilledema, and the presence of a CSF shunt.

PBR: Infectious Disease (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions