Pod: Infections Of Cns (Exam 2)

Front 1

Most common cause of meningitis in neonates (<1 month)

Back 1

Group B Streptococci

Front 2

Most common cause of meningitis in teenagers 11-17 years of age:

Back 2

Neisseria meningitidis

Front 3

Most common cause of meningitis in people over 65 years of age:

Back 3

Strep Pneumoniae

Front 4

What seasons does N. Meningitidis peak?

Back 4

Winter & Spring

Front 5

How many serogroups are there for N. Meningitidis?

Which cause a more focal outbreak?

Back 5

3 types: A,B,C

Groups B & C cause more focal outbreak

Front 6

Incubation period for N. Meningitidis:

Back 6

1 to 4 days

Front 7

(T/F) N. Meningitidis can be part of a person's normal flora in their nasopharynx.

Back 7

TRUE

Front 8

(T/F) S. Pneumoniae can be part of a person's normal flora in their nasopharynx.

Back 8

TRUE

Front 9

Risk factors that predispose to pneumococcal meningitis:

There's a lot of them!

Back 9

Pneumonia, Asplenic states, otitis media, injury, sinusitis, head injury, multiple myeloma, Sickle Cell,
Alcoholism, Wiskott-Aldrich syndrome, CSF leak

Front 10

H. Influenzae is Gram____, it's shape is _____, and it its air requirement is_____.

Back 10

H. Influenzae is Gram negative, it's shape is pleomorphic coccobacilli, and it is a facultative anaerobe.

Front 11

Why do infants (<2 years old) have trouble fighting H. Influenzae B?

Back 11

Because the bug has a capsule

Front 12

Most invasive serotype of H. Influenzae:

Back 12

Type B

Front 13

Two virulence factors of H. Influenzae:

Back 13

1. Capsule
2. LPS

Front 14

This bug is nonspore-forming, nonmotile, oxidase-positive, Gram (-), kidney bean-shaped cocci
(diplococci on smears)

Back 14

Neisseria meningitidis

Front 15

Which of the following types of N. meningitidis is on the rise?

A. A
B. B
C. C
D. D

Back 15

Type C is on the rise.

Front 16

(T/F) N. meningitidis is non-capsule forming.

Back 16

False.

The serotypes of N. meningitidis are classified by the capsule

Front 17

This bug is nonspore-forming, nonmotile, Gram(+), and appear as lancet shaped on smears.

Back 17

Streptococcus pneumoniae

Front 18

Key virulence factor for Streptococcus pneumoniae:

Back 18

Capsule

Front 19

(T/F) There is no relationship between the strains of Streptococcus pneumoniae that cause pneumonia, and the strains that cause meningitis.

Back 19

False! There is a direct relationship between the two.

Front 20

Why should a physician be concerned if he/she sees meningitis caused by E. coli?

Back 20

This is a sign of more underlying problems, or head trauma

Front 21

Three general steps in the hematogenoue route for bacterial meningitis infection:

Back 21

1.Colonization of mucosal surfaces.
2. Invasion into the blood stream.
3. Access to ventricles and subarachnoid space via choroid plexus & cerebral capillaries

Front 22

Three ways that bacteria can cause meningitis through direct extension:

Back 22

1. Middle ear & sinus infection
2. Skull fractures
3. congenital dural defects

Front 23

Four reasons why the host response is inadequate once bacteria reach the sub-arachnoid space:

Back 23

1. Low complement levels in CSF
2. Low immunoglobulin levels
3. Inefficient phagocytosis
4. Adherence of neutrophils to vascular endothelium.

Front 24

What is subarachnoid arteritis? What can it lead to?

Back 24

Inflammation of the blood vessels in the subarachnoid space.

Blood vessels can close up, leading to stroke.

Front 25

Condition that results when CSF flow is blocked at the level of the 4th ventricle:

Back 25

Obstructive hydrocephalus

Front 26

Type of edema caused by increased capillary permeability with increased extracellular fluid:

Back 26

Vasogenic edema

Front 27

Type of edema caused by increased intracellular water and sodium resulting in cell swelling:

Back 27

Cytotoxic edema.
Note that dead tissues swell.

Front 28

Cerebral perfusion pressure (CPP) equals:

A. MAP - ICP
B. MAP + ICP
C. ICP - MAP

Back 28

Cerebral perfusion pressure equals mean arterial pressure minus Intercranial pressure.

A is the correct answer.

Front 29

What happens to cerebral perfusion pressure during meningitis? Why?

Back 29

Cerebral perfusion pressure decreases.

Edema leads to increased intercranial pressure, while septic shock leads to a decrease in mean arterial pressure (hypotension).

CPP = MAP - ICP

Front 30

Pathology of late stage bacterial meningitis:

Back 30

Loss of cerebral autoregulation (due to cell death) leads to sub arachnoid exudates around cranial nerves.
Cortical/subcortical arterial and venous thrombosis leads to ischemia and infarction.
Ischemia/infarction leads to large increase in cerebral edema.
Edema leads to herniation through foramen magnum.
Herniation leads to death.

Front 31

Which of the following stages of meningitis do you first start seeing clinical symptoms:

A. colonization
B. Local invasion
C. Bacteremia
D. Meningeal invasion

Bonus question: What symptoms do you usually see at that point?

Back 31

C. Bacteremia

You typically see flu-like symptoms during this stage.

Front 32

Which stage of bacterial meningitis would you see positive Kernig's and Brudzinski's signs?

A. Bacteremia
B. Meningeal inflammation
C. Cerebral edema
D. Increased intracranial pressure (following edema)

Back 32

B. Meningeal inflammation

Front 33

Five end results of bacterial meningitis causes due to increased intracranial pressure:

Back 33

Brain edema
Increased CSF volume
Increased intracerebral blood volume
Herniation
Reduced cerebral perfusion pressure (CPP)

Front 34

Five end results of bacterial meningitis due to abnormalities of cerebral blood flow:

Back 34

Reduced cerebral profusion pressure (CPP)
Systemic hypotension
Cerebral vasculitis/vasopasm/thrombosis
Decreased brain metabolism
Loss of cerebrovascular autoregulation

Front 35

What should you do, (and not do) if history and neurologic exam suggest focal lesion?

Back 35

Do not perform a LP.
Instead do a neuroimaging procedure, and start on antibiotics.

Front 36

Four findings that would suggest viral meningitis (via enterovirus) as a differential diagnosis to bacterial meningitis:

Back 36

Insidious onset and slower progression in viral meningitis
Complaints of incapacitating headache, but otherwise alert and awake in viral form
Lower fever in viral meningitis
General malaise, but without stupor, obtundation, or coma

Front 37

Four symptoms/signs common in children with bacterial meningitis (occurs in >80% of cases):

Back 37

Fever
Nuchal rigidity (in children over 12 months old)
Headache (older children)
Nausea and vomiting

Front 38

Symptoms and signs of bacterial meningitis in teens and adults:

Back 38

Symptoms: Fever, headache, lethargy/confusion/coma, nausea/vomiting, photophobia, respiratory symptoms.

Signs: Nuchal rigidity, altered level of consciousness, seizures, focal neurologic deficits

Front 39

(T/F) The majority of patients with either bacterial or viral meningitis will have SIADH?

Back 39

False - SIADH is rare in aseptic meningitis.

Front 40

Which bacteria (Gram positive, or Gram negative) can cause cavities in the brain?

Back 40

Gram Negative

Front 41

Five meningitis-causing bacteria that produce beta lactamase:

Back 41

H. flu
M. Cat
Staph
E. coli
Kleb

Front 42

Preferred antibiotics for meningitis for newborns to 2 months of age (2):

Back 42

Thrid generation ceph.
Ampicillin

Front 43

Preferred antibiotics for meningitis for children over 2 months of age (2):

Back 43

Either third generation cepth OR ampicillin + chloramphenicol

Front 44

What is the most common sequelae in children with meningitis (if they have a sequelae)?

Back 44

Deafness

Front 45

Definition of aseptic meningitis:

Back 45

Subarachnoid inflammation not due to bacteria or fungal infection (usually due to viruses)
Also could be a noninfectious etiology.

Front 46

Most common cause of encephalitis?

This is a potential board question!

Back 46

Enteroviruses (85% of cases)

Front 47

Laboratory signs of aseptic meningitis:

Back 47

Varying WBC counts (neutrophils can vary as well though increase in poly's early on, and lymphocytes later on)
Moderate increase in protein

Front 48

A (low/high) CSF glucose, (low/high) protein count, a (low/high) WBC count, and a (low/high) neutrophil count will lead to a 99% prediction of bacterial infection

Back 48

You can make a 99% accurate prediction of bacterial infection based on LOW glucose, HIGH protein, HIGH WBC's, and HIGH neutrophil count.

Front 49

Presentation for aseptic meningitis:

Back 49

Accute onset (can be insidious)
Febrile and headache
Infants w/ fever and irritability
Pharyngitis & rash
Meningeal signs in children/adults
Mid to late summer predominance

Front 50

Are seizures common in aseptic meningitis?

Back 50

No!

Front 51

A 19 year old man had mono. However, after he recovered from his illness, he started to show encephalitis like symptoms.

What class of encephalitis is this? What likely caused this presentation?

Back 51

This is postinfetious encephalitis.

Typically this occurs because of cross reactive antibodies.

Front 52

Which season do you typically see herpes related encephalitis?

Back 52

Winter

Front 53

In which condition would you suspect to see an abnormal EEG?

Back 53

Encephalitis