Meningitis 01.15

Question 1

|nflammation of the parenchyma of the brain is called

Answer 1

Encephalalitis

Question 2

Inflammation of the dura, pia and arachnoid is called

Answer 2

Mengingitis

Question 3

Incidence of meningitis is highest in what age group?

Answer 3

<2yo - 81/100 000

Question 4

What 4 ways do pathogens enter the CNS?

Answer 4

1. Blood borne infections
2. Direct implant (e.g. skull fracture, iatrogenic (infected LP) congenital)
3. Local spread of infection - eg ear infection, sinus, tooth.
4. PNS - e.g. rabies, latent HSV / VZV

Question 5

Pathogens crossing the Brain Microvascular Endothelial Cells (BMEC) in the brain PARENCHYMA, generally cause what type of inflammation

Answer 5

Encephalitis - infection of brain parenchyma / cortex

Question 6

Pathogens crossing the Brain Microvascular Endothelial Cells (BMEC) in the CHOROID PLEXUS of the VENTRICLES, generally cause what type of inflammation

Answer 6

Mengingitis - CSV travels to Arachnoid with pathogen.

Question 7

What are the 2 main reasons that the BMEC / blood brain barrier in the brain parenchyma is more difficult for pathogens to cross.

Answer 7

1. V tight capillary endothelial junctions (=low paracellular flux)
2. Slow endocytosis of stuff through the cell - (low transcellular flux)

Question 8

What are the 3 main reasons it is easier for pathogens to pass through the BMEC / blood brain barrier in the choroid plexus of the ventricles

Answer 8

1. Capillary endothelial cells fenestrated = incr. permeability
2. Weaker endothelial “tight” cell junctions - higher paracellular flux.
3. Fast endocytosis in epithlium - faster transcellular flux

Question 9

Which is the most common cause of meningitis - virus or bacteria?

Answer 9

Virus

Question 10

What would you expect in a CSF profile result from BACTERIAL meningitis and why?:

1. Gross appearance
2. Blood cells (lymphocytes / neutrophils?)
3. Protein
4. Glucose
5. Positive stain for pathogens

Answer 10

1. Gross appearance - Very turbid (heavily contaminated with bact and WBCs)
2. Blood cells - neutrophils/polymorphs = WBCs for acute infection
3. Protein - RAISED= incr in WBCs and bacteria bodies
4. Glucose - LOW - being used up by active WBCs and bacteria.
5. Positive stain for pathogens - Gram stain

Question 11

What would you expect in a CSF profile result from VIRAL meningitis and why?:

1. Gross appearance
2. Blood cells (lymphocytes / neutrophils?)
3. Protein
4. Glucose
5. Positive stain for pathogen

Answer 11

1. Gross appearance - Clear - turbid
2. Blood cells - Lymphocytes (viral infect.) 3. Protein - normal (maybe slightly raised)
3. Glucose - Normal (virus not using it)
4. Positive stain for pathogens - None

Question 12

What would you expect in a CSF profile result from MYCOBACTERIAL (e.g. TB) meningitis and why?:

1. Gross appearance
2. Blood cells (lymphocytes / neutrophils?)
3. Protein
4. Glucose
5. Positive stain for pathogens

Answer 12

1. Gross appearance - Clear - turbid
2. Blood cells - Lymphocytes (TB = chronic infection)
3. Protein - RAISED
4. Glucose - LOW (TB and WBCs using it)
5. Positive stain for pathogens - Acid Fast

Question 13

What would you expect in a CSF profile result from FUNGAL meningitis and why?:

1. Gross appearance
2. Blood cells (lymphocytes / neutrophils?)
3. Protein
4. Glucose
5. Positive stain for pathogens

Answer 13

1. Gross appearance - Clear - turbid
2. Blood cells - Normal (some Lymphocytes)
3. Protein - Normal (slightly raised)
4. Glucose - LOW (fungi using it)
5. Positive stain for pathogens - India ink

Question 14

Two main causes of viral meningitis

Answer 14

Echo

Cocksackie virus A&B

Question 15

Latent virus that can cause meningitis in rare cases (usually just cold sores)

Answer 15

HSV - Herpes simplex virus

Question 16

2 main causes of bacterial meningitis in uk

Answer 16

Neisseria meningitidis

Streptococcus pneumoniae

Question 17

Rare cause of bacterial meningitis now due to effective vaccine programme

Answer 17

Haemophilus influenzae B (HiB)

Question 18

Latent mycobacterial cause of meningitis with gradual onset

Answer 18

TB

Question 19

Most common 4 bact causes of meningitis age 1m - 3m

Answer 19

Group B strep (39%)
G –ve bacilli (14%)
S pneum (14%)
N mening (12%

Question 20

Most common 4 bact causes of meningitis age 3m - 3yrs

Answer 20

S pneum (45%)
N mening (34%)
Group B strep (11%)
G –ve bacilli (9%

Question 21

Most common 2 bact causes of meningitis age 3yrs - 10yrs

Answer 21

S pneum (47%)
N mening (32%)

Question 22

Most common cause of meningitis ≥ 10 years & < 19

years

Answer 22

N mening (55%)

Question 23

Unknown cause but suspected bact meningitis - best initial antibiotic In GP surgery.

Answer 23

1. Benzylpenicillin (IM) / (cephalosporin if allergy)

Question 24

Contraindications to performing a LP (4)

Answer 24

Red. LOC
Neurological defecit
Suspected raised ICP
Infected skin at LP site

Question 25

Best antibiotic therapy for NEONATES

Answer 25

Ampicillin & an aminoglycoside or a cephalosporin | cefotaxime

Question 26

Best antibiotic therapy for <3months

Answer 26

Ampicillin & cephalosporin (ceftriaxone or | cefotaxime)

Question 27

Best antib. for older children

Answer 27

– Cephalosporin (eg, cefotaxime, ceftriaxone)

Question 28

Giving corticosteroids is thought to reduce what complication of meningitis in adults?

Answer 28

Deafness

Question 29

Complications of meningitis (11)

Answer 29

``` Focal neurological sequelae - 10-15% • Hemiparesis • Facial palsy • Visual field defects • Hearing loss • Blindness Cranial nerve palsies • Seizures • Hydrocephalus • Septicaemia • Most children with enteroviral meningitis have an uncomplicated course ```

Question 30

A patient with meningitis (but could also be lung cancer, other infections etc) shows hyponatraemia in the blood U&Es. Why might this be?

Answer 30

SIADH - Syndrome of innapropriate ADH secretion - disease causes hypothalamus to produce ADH therefore preventing fluid loss at kidneys therefore sodium in blood is diluted by excess fluid = dilutional hyponatraemia.

Question 31

3 most common uterine causes of meningitis

Answer 31

CMV Rubella Toxoplasmosis

Question 32

This viral cause of meningitis, commonly uterine, causes Necrotising encephalitis---calcification mental retardation, microcephaly, deafness

Answer 32

CMV

Question 33

This viral cause of meningitis, commonly uterine, causes Abortion/stillbirth. Severe brain/other organ damage. Mod cerebral damage, chorioretinitis,

Answer 33

Toxoplasmosis

Question 34

This viral cause of meningitis, commonly uterine, causes Heart defects, cataracts, deafness, mental retardation

Answer 34

Rubella

Question 35

What damage does the very rare post infectious immune mediated encephalomyelitis cause to nerves

Answer 35

Demyelination

Question 36

This type of meningitis is caused by antibodies to neuronal proteins (anti VGKC and anti NMDA receptor)

Answer 36

Auto immune meningitis

Question 37

CJD and spongiform encephalopothies are caused by this modified form of a normal structural protein.

Answer 37

Prions

Question 38

These 3 vaccines are all effective against different viral meningitis strains

Answer 38

Hib (Haemophilus influenzae B) Meningococcal C PCV (Pneumococcal conjugate vaccine)

Question 39

These three diseases can cause encephalitis and are given as single vaccine at 12/13 months

Answer 39

MMR

Question 40

This vaccine is not routine any more but is given to neonates with family members from high risk countries for the disease.

Answer 40

BCG for TB

Question 41

True or false - antibiotic chemoprophylaxis in communities will protect the individuals from getting meningitis

Answer 41

False - the antibiotic will remove N. meningitidis orgs from healthy carriers, thus reducing the chance of them infecting others. It has no protective effect for the individual, but protects the community from increased infectious events.

Question 42

What is the danger of people beleiving that antibiotic chemoprophylaxis will protect them from meningitis.

Answer 42

That they will not think they have meningitis even if they get symptoms - must brief people appropriately before giving the drug.

Question 43

N lactamina is in the nose and throat of many kids, what is the danger of antibiotic chemoprophylaxis against meningitis in this population.

Answer 43

N lactamina is harmless but involved in development of immunitiy in children, antibiotic will remove this org and so poss compromise future immunity against disease in the kids.

Question 44

These 2 drugs are also recommended for PROPHYLAXIS of meningitis (not treatment), but less favoured than ciprofloxacin. List them and the issues with them.

Answer 44

Rifampicin - CYP enzyme inducer so interacts with other drugs Ceftriaxone - must be given by injection

Question 45

First line drug for CHEMOPROPHYLAXIS of bact meningitis

Answer 45

Ciprofloxacin.

Question 46

Main groups of people who should receive CHEMOPROPHYLAXIS for bact meningitis

Answer 46

Household members | Close, prolonged contact - intimate kissing, kids staying overnight in same room / eating together.