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Flashcards in Focal CNS infections Deck (21)
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1
Q

General causes of brain absecesses

A

 #1. Direct extension from contiguous site

 #2. Hematogenous from distant site

 #3. External

2
Q

Direct extension from contiguous site for brain abcesses

A

 Sinusitis

 Dental abscess

 Otitis

 Mastoiditis

3
Q

Direct extension from contiguous site

 Pathogens

A

Streptococcus pneumoniae

Haemophilus influenzae

 Anaerobes

  Bacteroides, Prevotella

 Staphylococcus aureus

 Actinomyces,

4
Q

Papilledema

A

Optic disc swelling that is due to raised intracranial pressure

5
Q

STREPTOCOCCUS PNEUMONIAE

Characteristics

A

Refer to picmonic

6
Q

STREPTOCOCCUS PNEUMONIAE

Risk factors

A

 HIV

 Diabetes

 Steroid therapy

 Asplenia

7
Q

STREPTOCOCCUS PNEUMONIAE

 Virulence factors

A

 Surface protein adhesins

 Allows colonization, binding to epithelial cells

 Ig-A protease

  Disrupts secretory Ig-A mediated clearance

 Pneumolysin

 Destroys respiratory epithelium

 Capsule

 Antiphagocytic
8
Q

STREPTOCOCCUS PNEUMONIAE

 Clinical disease

A

 Sinusitis

 Otitis

 Common in children

 Pneumonia

 Lobar

 Rust-colored sputum

 Meningitis

9
Q

HAEMOPHILUS INFLUENZAE

Risk factors

A

 Age

 Asplenia

 Chronic pulmonary disease  Smoking

 Alcoholism

10
Q

#2. Hematogenous spread from distant site

causes

A

 Endocarditis

 Respiratory tract infection

 Lung abscess

 Mixed aerobes & anaerobes

 Atypical organisms

  Nocardia
11
Q

STAPHYLOCOCCUS AUREUS

Characteristics

A

Check picmonic

12
Q

STAPHYLOCOCCUS AUREUS

Virulance factor- Toxin

A

Check picmonic

13
Q

STAPHYLOCOCCUS AUREUS

 Virulence factors

 Enzymes

A

 Staphylokinase

  AKA fibrinolysin

  Dissolves fibrin clots
14
Q

Actinomyces characterisitcs

A

Check picmonic

15
Q

 Craniotomy

 Skin flora

A

 Grampositive

 Staphylococci(S.aureus,CONS)

 Bacillus sp.

 Propionibacter

 Corynebacterium

16
Q

 Craniotomy

Nosocomial pathogens

A

 Enterobacteriaceae

 Klebsiella

 E. coli

 MRSA

 Resistance

17
Q

 JC virus

A

 “Progressive multifocal leukoencephalopathy”

 Demyelinating disease of white matter

 Reactivation of virus when individual becomes immunosuppressed

 HIV(CD4<50mm3),organ transplantation, chemotherapy

18
Q

JC VIRUS / PML

 Diagnosis

A

 Lumbar puncture

 “Bland” CSF

 Detection of myelin basic protein

 As result of demyelination

 Also seen in multiple sclerosis

 CSF JC virus PCR

19
Q

EBV CD4 count

A

Lymphoma CD4 <50 mm

20
Q

Toxoplasmosis CD4 count

A

CD4 <100

21
Q

ASPERGILLUS vs mucor

A

Aspergillus

 Narrow

 Septated hyphae

 Acute angle branching (typically 45 degrees)

mucor

 Broad,nonseptate,widerangles