Brain abscess

Question 1

Define it

Answer 1

A suppurative (pus producing) collection of microbes (often bacterial, fungal or parasitic) within a gliotic capsule occurring within the brain parenchyma

Question 2

What are different ways it’s caused?

Answer 2

Spread of an infection
- Sinusitis
- Endocarditis
- Meningitis
- Otitis media
Trauma or surgery to scalp
Penetrating head injuries

Question 3

What are the most common pathogens causing it? (2)

Answer 3

• Strep viridans (secondary to sinusitis)
• Staph aureus

Question 4

In which demographics is it most common? (2)

Answer 4

• Adult men <30 yrs
• Children 4-7 yrs

Question 5

Clinical features

Answer 5

Features of raised ICP:
- Nausea
- Vomiting
- Seizures
- Papilloedema
Dull, persistent headache
Fever
Focal neurology
Positive Kernig or Brudzinski sign

Question 6

how is the headache different to when the abscess ruptures

Answer 6

You see sudden worsening of headache and meningism

Question 7

Focal neurology caused by what

Answer 7

3rd or 6th nerve palsy
CN6 most likely to be compressed due to raised ICP as it has longest course

Question 8

1st line investigation

Answer 8

MRI with contrast → best initial test, can see one or more ring-enhanced lesions

Question 9

What investigation will give confirmation of an abscess?

Answer 9

Biopsy

Question 10

What other scan can we do?

Answer 10

CT head (with or without contrast)

Question 11

What bloods would we check?

Answer 11

Elevated ESR/CRP

Question 12

1st line management

Answer 12

Surgery - craniotomy is performed and the abscess cavity debrided

Question 13

What drugs do we give? (2)

Answer 13

IV antibiotics → 3rd gen cephalosporin (ceftriaxone) + metronidazole

Question 14

How do we manage ICP?

Answer 14

Dexamethasone

Question 15

What do we give for seizure prophylaxis?

Answer 15

Anticonvulsants

Question 16

Complications? (4)

Answer 16

• Seizures
• Hydrocephalus
• Hyponatremia
• Death