Brainscape's Knowledge GenomeTM

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


See full index

Infectious Diseases > CNS Infections > Flashcards

CNS Infections Flashcards

1
Q

Direct spread of intracerebral abscess pathogens

A

-Solitary head and neck infections
=Chronic otitis media
=Mastoiditis
=Frontal sinusitis
=Dental
=Trauma or surgery to scalp, penetrating head injury

-Oral streptococci
-Haemophilus spp
-Bacteroides spp
-Fusobacterium spp
-Prevotella spp
-Enterobacteriacae
-Pseudomonas aeurginosa

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

Haematogenous spread of intracerebral abscess conditions

A

-TRVAEL THROUGH LEFT SIDE OF BODY
-MCA territory, multiple abscess at grey-white matter junction (disruption of BBB)

-Endocarditis
-Chronic pulmonary infection
-Pulmonary arterio-venous
malformations
-Skin infection
-Pelvic infection
-Intra-abdominal infection
-Presence of prosthetic material

=Streptococci
=S. aureus
=Less common= fusobacterium

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

Pathogens in neurosurgical intervention for intracerebral abscess

A

-Staphylococcus spp
-Streptococcus spp
-Pseudomonas aeurginosa spp
-Enterobacter spp

-Remember pre-surgical colonisation (MRSA positive?)

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

Pathogens in intracerebral abscess via immunocompromise

A

-Toxoplasma
-Mycobacteria spp
-Listeria spp
-Nocardia spp
-Aspergillous spp
cryptococcal
coccidioides
-Candida spp

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

Pathogens leading to intracerebral abscess via travel

A

-Cysticercosis
-Entamoeba
-Schistosoma
-Paragonimus

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

Clinical presentation of intracerebral abscess

A

-Headache (often dull, persistent)
∙ Fever (usually not swinging, may be absent)
∙ Focal neurological signs (oculomotor nerve palsy, abducens, secondary to raised ICP)
-Nausea
-Papilledema
-Seizure

∙ Seizure activity
∙ Raised intracranial
pressure
=CN III and VI lesions, papilloedema

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

Examination in intracerebral abscess

A

→ Otoscopy / ENT exam
→ Heart sounds
→ Review of prosthetic
material
→ Recent Neurosurgery

=Intracerebral bleed
=Malignant process
=DIFFERENTIALS

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

Investigations in intracerebral abscess

A

-ASPIRATION AND CULTURE
∙ Routine bloods (inflammatory markers)
∙ Blood cultures
∙ CT head with contrast= lesions more differentiated
∙ MRI
∙ (CSF examination- may be necessary, raised ICP considered?)
∙ HIV test
∙ serology

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

Treatment for intracerebral abscess

A
  • Neurosurgical input for drainage (craniotomy with abscess debridement)
    – routine culture
    – mycobacterial culture/mycology culture
    – pathology
    – molecular techniques
  • Empirical antibiotics
    – IV ceftriaxone /ceftazidime and IV metronidazole (cover anaerobic infection)
    -Intracranial pressure management: dexamethasone
  • Specialist advice following Neurosurgery
    – IV ceftazidime, IV vancomycin and IV metronidazole

=4-8 weeks, radiological follow up (oedema, fibrotic capsule, scarring)
=Mortality 10%, seizure activity?

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

Pathogenesis of meningitis

A

-Colonisation= nose/ear
-Invasion
-Blood stream survival
-Infection= crossing BBB into CSF space
-Significant host response

-25% meningitis

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

Category and cause of meningitis

A

-Bacterial

-Viral
=Enterovirus
=Mumps
=Measles
=HSV
=VZV
=Influenza

-Fungal
=Cryptococcal

-Other organisms
=Rickettsia
=Protozoa
=Helminths

-Non-infectious presentation (meningism= inflammation not infection)
=Migraine
=SAH
=Vasculitis

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

Common organisms in 0-4 weeks

A

Group B streptococcus, E.coli, L.monocytogenes, K.pneumoniae,
Enterococcus spp., Salmonella spp.

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

Common organisms in 4-12 weeks

A

(Group B streptococcus, E.coli, L.monocytogenes, K.pneumoniae,)
H.influenzae, S.pneumoniae, N.meningitidis

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

Common organisms in 3 months-18 years

A

H.influenzae, S.pneumoniae, N.meningitidis

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

Common organisms in 18-60 years

A

S.pneumoniae, N.meningitidis

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

Common organisms in >60 years

A

S.pneumoniae, N.meningitidis, L.monocytogenes, gram negative
bacilli, (Mycobacterium tuberculosis)

17
Q

Common organisms in Immunocompromised

A

S.pneumoniae, N.meningitidis, L.monocytogenes, gram negative
bacilli, Mycobacterium tuberculosis

18
Q

Common organisms in CSF shunt

A

S.aureus, coagulase negative staphylococci, gram negative bacilli

19
Q

Clinical presentation in meningitis

A
  • Fever
  • Headache
  • Neck stiffness
    -Vomiting
  • Rash

-Seizure
-Altered consciousness
-Focal neurological deficit

20
Q

Investigations in meningitis

A
  • ABCDE and senior clinical assessment
  • Routine bloods including coag
  • Blood cultures
  • Bacterial and viral throat swabs
  • HIV test
  • Blood PCR
    – S.pneumoniae, H.infuenzae, N.meningitidis

-Lumbar puncture
-(CT scan)

21
Q

Clinical indications for CT in meningitis

A

-Focal neurological signs
=Papilledema
=Continuous or uncontrolled seizures
=GCS 12
(Decompression in LP if raised ICP)

  • Delays antibiotics
  • Delays LP
    – Prior to abx CSF diagnostic in 70-85%
    – CSF can be sterile 2-4 hrs after the first dose of abx
    – Prior abx can cause
    lymphocyte predominance
22
Q

Indications for lumbar puncture samples in meningitis

A

∙ microscopy
∙ gram stain
∙ routine culture
∙ PCR
∙ S.pneumoniae, H.infuenzae, N.meningitidis
∙ biochemistry
∙ glucose / protein / lactate
∙ pathology
∙ mycobacterial stain/culture
∙ other

23
Q

Bacterial lumbar puncture interpretation

A

-Increased opening pressure (increased inflammatory response)
-Turbid appearance
-Severely increased WCC, predominantly NEUTROPHILS
-<50% plasma glucose (high metabolic requirement of bacteria)
-Moderately increased protein

24
Q

Viral lumbar puncture interpretation

A

-Normal or increased opening pressure
-Clear appearance
-Raised WCC, predominantly lymphocytes
-Normal glucose
-Normal protein

25
Q

Fungal/ TB lumbar puncture interpretation

A

Moderately increased opening pressure
-Turbid/fibrin web appearance
-Moderately increased WCC, predominantly LYMPHOCYTES
-<50% plasma glucose
-Moderately/ severely increased protein

26
Q

Treatment for Meningitis

A
  • Ceftriaxone 2g 12hr
    – Meropenem/chloramphenicol alternative (penicillin allergy)
  • Add IV amoxicillin 2g 4hr for Listeria spp if
    – >60y
    – Immunocompromise
    – Co-trimoxazole alternative
  • Add IV vancomycin 15-20mg/kg BD
    – 6m travel to country with penicillin resistant pneumococci
  • 10mg IV dexamethasone 6hr pre abx
    – Empirical treatment for all, if pneumococcal meningitis continue for 4d
    -Reduce mortality, hearing loss
  • Aciclovir 10mg/kg TDS
27
Q

Treatment duration for Neisseria meningitidis

A

5d ceftriaxone

28
Q

Treatment duration for Streptococcus pneumoniae

A

10-14d benzylpenicillin/ ceftriaxone

29
Q

Treatment duration for Listeria monocytogenes

A

21d high dose amoxicillin

30
Q

Treatment duration for Haemophilus influenzae

A

10d ceftriaxone

31
Q

Management of viral meningitis

A

-Viral PCR= enterovirus (other)
-Stop antibiotics and antivirals
-Supportive treatment
-Discuss with specialist team if concerns

32
Q

HSV1 encephalitis pathophysiology

A

-Primary infection (enters skin through mucosa to infect nerve endings)
-Latent phase (replicates in root ganglia, trigeminal and maxillary branch)
-Reactivation phase (stress/ illness/ immunocompromise/ idiopathic- meningeal branches into temporal lobe)

-VIRAL AETIOLOGY MOST COMMON: HSV1 (5%)- temporal and inferior lobes

33
Q

Clinical presentation of encephalitis

A

∙ Altered mental status / behaviour / personality (psychiatric symptoms)
∙ Seizure activity (temporal and inferior frontal lobe involvement): aphasia
∙ Fever – low grade
-Headache
-Vomiting
∙ Focal neurology – subtle, aphasia
∙ (meningeal irritation)
∙ Rash – vesicular (GU exam, HSV latency), cold sores often no relation
∙ Recent immunocompromise
∙ Travel history
∙ Vector exposure

34
Q

Clinical investigation of encephalitis

A

∙ CT head with contrast: medial temporal and inferior frontal changes (petechial haemorrhages) can be normal
∙ LP:
=PCR for HSV1 (95%), HSV2, VZV, enterovirus
=Lymphocytosis, elevated protein
∙ Routine culture
∙ Biochemistry

∙ Blood cultures
∙ Baseline serology
∙ HIV test

∙ MRI! - temporal lobe changes, oedema, petechial haemorrhages
∙ EEG (lateralised periodic discharges at 2 Hz)
∙ Brain biopsy

35
Q

Differential diagnosis of encephalitis

A

∙ Tumour
∙ Medication / substance misuse
-Delirium
∙ Autoimmune
∙ Vasculitis
∙ Paraneoplastic

36
Q

Treatment of encephalitis

A

∙ High dose IV acyclovir 10mg/kg TDS
=May need to consider repeat lumbar puncture

∙ Continue for 14days then repeat LP
=If HSV PCR negative stop treatment
=If HSV PCR positive then further 7 days and repeat LP

∙ Assess cognitive function

Infectious Diseases (25 decks)

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