CNS Infections Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Define meningitis

A

Infection in sub arachnoid space of the LEPTOmeninges

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

Clinical features in infant with meningitis

A

Bulging fontanelle, crying, poor feeding

Non blanching rash

Headache, neck stiffness, fever vomiting etc…

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

CSF findings in viral meningitis (lymphocytes, neutrophils, glucose, protein)

A

Lymphocytes: High

Neutrophils: Low

Glucose: normal

Protein: Slightly elevated

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

CSF findings in bacterial meningitis (lymphocytes, neutrophils, glucose, protein)

A

Lymphocytes: Slightly raised

Neutrophils: Very raised

Glucose: Very low

Protein :elevated

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

CSF findings in TB meningitis (lymphocytes, neutrophils, glucose, protein)

A

Similar to virus except glucose is low and ziel neelson is +ve

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

Cause of intracellular meningitis?

A

Neisseria meningitidis

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

Cause of intercellular meningitis?

A

Haem. influenzae

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

How do neisseria men. and H. influenze overcome the immune system to cause meningitis?

A

Polysaccharide capsules are able to evade complement system in blood

Once in CNS, there is no complement system so they grow unimpeded

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

How is the BBB broken down in meningitis? (recognise)

A

Bacteria replicate and lyse

This causes release of interleukins IL1, IL6 and TNF

Polymorphs are attracted to infection site

THis causes endothelial disruption, albumin leak, and CEREBRAL OEDEMA!!

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

Most common causes of meningitis in infants?

A

Group B strep

E coli

Listeria

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

Most common causes of meningitis in toddlers

A

N. meningitis

Strep pneumoniae

H influenzae

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

Most common cause of meningitis in adults

A

N. meningitidis

S. pneumoniae

(H. influenzae less common)

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

What are the ‘NHS’ bacteria?

A

Neisseria meningitis

H. influenzae

Strep pneumonia

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

Who gets neisseria meningitis? What is it sensitive to?

A

Children and YAs

Penacillin

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

Who gets H. influenzae? What is it resistant to?

A

Young kids

B lactamase +ve, so penicillin resistant

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

Who gets strep pneumoniae? What is is resistant to?

A

Extremes of age

Starting to see penicillin resistance

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

What type of organism is strep pneumoniae? What do you see on blood agar?

A

Gram +ve diplococci

Draughtsman colony, green zone of haemolysis

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

What type of organism is Haemophilis influenzae?

A

Gram negative rod

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

Culturing requirements for H influenzae?

A

Needs X and V factors

Grows best on enrichment media eg chocolate agar

Smells like semen lol

Invasive strains are often capsulated.

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

Diseases caused by H influenzae?

A

Pneumonia

Meningitis

Epiglottitis

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

What type of organism is neisseria meningitidis?

A

Gram -ve diplococcus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Culturing features of neisseria meningitis?

A

Oxidase positive

IDENTIFIED SUGAR FERMENTATION

MeninGos do Maltose and Glucose!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Treatment of meningitis for adults and children

A

Ceftriaxone (/benzylpenicillin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Treatment of meningitis in infant?

A

Ampicillin + cefotaxime

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What immunotherapy can be used for meningitis?

A

Dexamethasone before antibiotic may decrease cerebral oedema in children

26
Q

What does Hib/menC vaccine protect against?

A

H influenzae and meningococcal meningitis group C

27
Q

Describe Hib vaccine components (recognise_

A

PRP polyribosylribitol phosphate

T cell independent (no IgG boost)

28
Q

New meningitis vaccines? (3)

A

New conjugate meningococcal group C

Meningococcal polysaccharide A, C (not B neisseria)

Pneumococcal 7 valent vaccines

29
Q

Which meningitis is not protected against with vaccines?

A

Group B Neisseria meningitis

30
Q

Prophylaxis for meningitis if there is an unimmunised child under 4 in the household?

A

Rifampicin

31
Q

Prophylaxis for menigitis?

A

Ciprofloxacin for all close contacts in past 10 days

32
Q

Viral causes of meningitis?

A

Enteroviruses -80%

Also:
HSV 2 (and 1)
VSV, CMV
Mups
Adenovirus
HIV
33
Q

Examples of enteroviral causing meningitis?

A

Coxsachie or echovirus most common

34
Q

Treatment of viral meningitis?

A

SUPPORTIVE

Anti-HSV not proven

May be preventable by vaccination

35
Q

Prognosis of viral meningitis?

A

Better than bacterial

36
Q

Non-viral causes of aseptic meningitis? (i.e couldn’t culture anything or use PCR identification)

A
Fungi
TB!!!
Syphillis
Brucella
Mycoplasma
Protozoa
Helminths
37
Q

Age group affected by TB meningitis?

A

<6 yrs

38
Q

How does TB meningitis present?

A

3-6 months after initial infection/exposure

Millary TB in 50%

GRADUAL ONSET:

  • personality change, irritability
  • FEVER, drowsiness, neck stiffness
  • decreased LOC
39
Q

**Tests for TB meningitis?

A

+ve TUBERCULIN test

+ve Mantoux

CSF clear and similar to viral CSF except with low glucose

Hard to diagnose under microscope as bacilli are scarce

Can also look at gastric washings

40
Q

Prognosis of TB meningitis?

A

Poor

41
Q

Treatment of TB meningitis?

A

4 drugs, RIPE for 10 months, then cute down to RI

42
Q

Organisms causing meningitis

in immunocompromised host?

A

Listeria in raw mik or soft cheese

Cryptococcus yeast

43
Q

Causes of encephalitis? (8)

A

MAINLY VIRAL

HSV 1 (most common)

Also:

  • Influenza
  • VSV
  • Enteroviruses
  • Rabies
  • Arboviruses
  • Hendra and Nipah viruses
  • Japenese B
44
Q

Non viral causes of encephalitis? (9) (recognise)

A
N. meningitidis
Listeria monocytogenes
Scup typhus
Leptospirosos
Melliodosis

Malaria
TB
Borrelia and Brucella

45
Q

Investigations and management of encephalitis

A

High dose aciclovir and abx if high suspicion

CSF
THroat and stool samples
INeural imaging, EEG

46
Q

Most common cause of encephalitis?

A

HSV 1

Causes 1-4 cases per million per year

80% of those untreated will die

47
Q

Clinical features of HSV1 encephalitis

A
Headache
Fever
Decreased LOC
Confusion
Dysphasia
48
Q

Treatment of HSV 1 encephalitis?

A

Aciclovir 14-21 days

49
Q

CNS complications of measles

A

Post infectious encephalitis (autoimmune)

Measles Inclusion body encephalitis (immunocompromised)

*** SSPE, Subacute sclerosing panencephalitis several years after exposure in children (progressive neurodegenerative condition)

50
Q

3 main types of demyelinating encephalopathies?

A

All are viral

  • Measles, SSPE, MIBE
  • Progressive multifocal encephalopthy by JC virus in AIDS
  • Rubella encephalitis
51
Q

What does the JC virus cause in the CNS of AIDS patients?

A

Progressive multifocal encephalopathy, a demyelinating disease

52
Q

Clinical features of a brain abcsess

A

Varied!

Headache, drowsiness, confusion

Seizures

N + V

Motor/sensory impairments

Papillodema and ataxia

53
Q

Causes of brain abscesses?

A

Contiguous suppurative focus 40-50% (otitis media or another infection crossing into CNS)

Haematogenous spread from distant infection 25%

Trauma 10%

54
Q

Common causes of brain abscess

A

Often polymicrobial

Staph aureus
Streptococci
Bacteriodes
Fusobacterum
Pseudomonas etc

Need to look at infection sourse

55
Q

Tx for abscess with unknown cause?

A

Cover for streptococci with penicillin or cefotaxime or ceftriaxone

56
Q

Tx for brain abscess causesd by staph aureus

A

Vancomycin

57
Q

Tx for brain abcess caused by pseudomonas aeruginoas

A

Cefepime or ceftazidime

58
Q

Tx for brain absess in HIV patient?

A

May need to consider cover for organisms like Toxoplasma

59
Q

3 examples of prion diseases

A

Sporadic CJD (dementia, ataxia, can detect 14-3-3 protein in CSF)

Familial Transmissable Spongiform Encephalopathies TSE (autosomal dominant)

Kuru

60
Q

Another name for bovine spongiform encephalopathy?

A

New variant CJD

mad cow disease, not spordaic

61
Q

Which prion disease has 14-3-3 protein in CSF?

A

New variant CJD

Also see a high T2 signal in post thalamus at MRI

Plaques on the brain

62
Q

Who gets new varieant CJD?

A

Younger patietns

60% have psychiatric symptoms initially