CNS Infections - Brain Abscesses and Other Infections (28)

Question 1

Different types of primary bacterial infections in CNS

Answer 1

• Meningitis
• Encephalitis
• Ventriculitis
• Brain abscess
• Ventriculoperitoneal shunt and external ventricular drain infection
• Subdural empyema
• Eye infections

Question 2

Brain abscess

Answer 2

Focal suppurative process within brain parenchyma (pus)

Question 3

Causes of brain abscesses

Answer 3

Polymicrobial, streptococci (strep milleri 60-70%), staph aureus (10-15%), anaerobes, gram neg enteric bacteria (E.coli), fungi, M TB, Toxoplasma gondii, Nocardia, Actinomyces

Question 4

4 pathogenesis of brain abscesses

Answer 4

1. Direct spread from ‘contiguous’ suppurative focus
2. Haematogenous spread
3. Trauma
4. Cryptogenic

Question 5

Direct spread from ‘contiguous’ suppurative focus

Answer 5

Ear (40%), sinuses, teeth

Question 6

Haematogenous spread from distant focus

Answer 6

Endocarditis, bronchiectasis (multiple abscesses)

Question 7

Trauma

Answer 7

Open cranial fracture, post-neurosurgery

Question 8

Cryptogenic

Answer 8

No identifiable reason

Question 9

Clinical presentation

Answer 9

Headache, focal neurological deficit, confusion, fever (

Question 10

Management

Answer 10

Drainage (treat 4-6 weeks antibiotics)

Question 11

Antibiotics

Answer 11

Penetrate CSF/BBB

- Ampicillin, Penicillin, Cefuroxime, Cefotaxime, Ceftazidime, Metronidazole

Question 12

Complications

Answer 12

Raised ICP, mass effect, coning, rupture (into ventricles) > ventriculitis

Question 13

Subdural empyema

Answer 13

Infection between dura and arachnoid mata

Question 14

Causes of subdural empyema

Answer 14

(Polymicrobial) anaerobes, streptococci, aerobic gram negative bacilli, streptococcus pneumonia, H.influenza, Staph aureus

Question 15

Pathogenesis of subdural empyema

Answer 15

• Spread of infection from sinuses (50-80%), middle ear and mastoid (10-20%),
• Haematogenous 5%
• Following surgery/trauma

Question 16

Clinical presentation subdural empyema

Answer 16

Headache, fever, focal neurological deficit, confusion, seizure, coma

Question 17

Management of subdural empyema

Answer 17

Urgent surgical drainage of pus and antimicrobial agents

Question 18

What is a ventriculoperitoneal (VP) shunt and external ventricular drain (EVD)?

Answer 18

Neurosurgical patients have it inserted into ventricles to monitor ICP/drain excess CSF

Question 19

VP shunt and EVD infections

Answer 19

Colonised with bacterias > ventriculitis

Question 20

Diagnosing VP shunt and EVD infections

Answer 20

CSF microscopy and culture

Question 21

Most common cause of VP shunt and EVD infections

Answer 21

Coagulase-negative staphylococci

Question 22

Treatment of VP shunt and EVD infections

Answer 22

Device removal, IV antibiotics