27 - Abscesses and Other CNS infection

Question 1

E.gs of primary bacterial infections

Answer 1

Meningitis
Encephalitis
Ventriculitis
Brain abscess
Ventriculoperitoneal shunt and ext. ventricular drain infection
Subdural empyema
Eye infections

Question 2

Brain abscess - clinical presentation

Answer 2

Headache
Focal neurological deficit
Confusion
Fever
Nausea, vomiting
Dizziness, seizures
Neck stiffness
Papilloedema, coma

Question 3

Brain abscess - management

Answer 3

Urgently reduce intracranial pressure
Confirm diagnosis
Obtain pus microbiological investigation
To enhance efficacy of antibiotics
Avoid spread of infection into ventricles

Question 4

What is a sinugenic brain abscess?

Answer 4

Frontal lobe brain abscess

Question 5

What is a odontogenic abscess?

Answer 5

Temporal lobe brain abscess

Question 6

Brain abscess - complications

Answer 6

Raised ICP
Mass effect
Coning (herniation to foramen magnum)
Rupture causing ventriculitis

Question 7

Subdural empyema - what is it?

Answer 7

Infection between dura and arachnoid mater

Question 8

Subdural empyema - causes

Answer 8

Anaerobes
Streptococci
Aerobic gram--ve bacilli
Strep. pneumoniae
Haemophilus influenze
Staph. aureus

Question 9

Subdural empyema - pathogenesis

Answer 9

Spread of infection from sinuses (50-80%)

Middle ear and mastoid (10-20%) or distant site (5%) and following surgery of trauma

Question 10

Subdural empyema - clinical presentation

Answer 10

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

Question 11

Subdural empyema - management

Answer 11

Urgent surgical drainage of pus
Antimicrobial agents
Need to culture pus

Question 12

Ventriculoperitoneal (VP) shunt and external ventricular drain (EVD) infection

Answer 12

Neurosurgical patients may have a device inserted into the ventricles to monitor ICP or drain excess CSF