Brain Abscesses and other infections of the central nervous system (CNS pathology) Flashcards
What are the different types of primary bacterial infections of the central nervous system?
- Menigitis
- Encephalitis
- Ventriculitis
- Brain abscess
- Subdural Empyema
What is a Brain Abscess?
Collection of pus within the brain parenchyma
What is the most common cause of brain abscesses following surgery?
Staphylococcus Aureus
What gram negative enteric bacteria is known to cause brain abscesses?
- E.Coli
- Pseudomonas spp.
What are the common causes of brain abscesses?
- Streptococci
- Staphylococcus Aureus
- E.coli / Pseudommonas
- Mycobacterium Tuberculosis
- Toxoplasma gondii
- Nocardia
- Actinomyces
What are the 4 clinical settings in which brain abscesses form?
1) Direct spread from areas with a common border e.g. ear, sinuses, teeth.
2) Haematogenous spread from distant focus
3) Trauma
4) Cryptogenic (no focus)
What is the clinical presentation of Brain Abscesses?
- Headache
- Neurological deficit
- confusion
- Fever
- nausea
- dizziniess / siezures
- Neck stiffness
- coma
How are brain abscesses managed?
DRAINAGE
1) to reduce intracranial pressure
2) confirm diagnoses
3 to obtain pus
4) enhance efficacy of antibiotics
5) to avoid spread to ventricles
What antibiotics are used to treat brain abscesses?
- Ampicillin
- Penicillin
- Cefuroxime
- Cefotaxime
- Ceftazidime
- metronidazole
What are the complications of brain abscesses?
1) Raised intracranial pressure causes CONING (prolapse of brainstem through foramen magnum)
2) Rupture into ventricles causing VENTRICULITIS
What is a Subdural Empyema?
Infection between dura and arachnoid mata
What are the causes of Subdural Empyema?
- Anaerobes
- Streptococci
- Aerobic Gram negative bacilli
- Streptococcus Pneumoniae
- Haemophilus Influenzae
- Staphylococcus Aureus
What is the most common site that infection causing subdural empyema can spread from ?
Sinuses
What is the clinical presentation of Subdural Empyema?
- Headache
- Fever
- Focal Neurological deficit
- confusion
- siezure
- coma
How is subdural empyema managed?
drainage of pus and antibiotics
