Brain abscesses and CNS infections Flashcards
Causes of brain abscess
Often polymicrobial
Streptococci Staph aureus Anaerobes Gram -ve entero bacteria Fungi
4 ways brain abscess can develop
Direct spread from ear, sinus, teeth…
Haematogenous e.g. endocarditis, brinchiectasis
Trauma
Cryptogenic- more common in immunocompromised
Presentation of brain abscess
Headache Focal neurological defecit Confusion Fever Nausea and vomiting Dizziness, seizures Neck stiffness Late signs- papilloedema and seizures
How to Dx brain abscess?
Imaging
Management of brain abscess?
Drainage to reduce ICP, confirm Dx, obtain microbiology pus sample, enhance efficacy of antibiotics and to avoid spread of infection to ventricles.
6 antibiotics used to treat brain abscess
Ampicillin Benzyl-penicillin Cefuroxime Cefotaxime Ceftazidime Metronidazole
Complications of brain abscess
Raised ICP
Mass effect
coning
Rupture causing ventriculitis
Causes of subdural empyema
Often polymicrobial
Anaerobes
Streptococci
Aerobic gram -ve
Pathogenesis of subdural empyema
Spread from sinuses, middle ear and mastoid or distant site, or following surgery or trauma
Presentation of subdural empyema
Headache Fever Focal neurological defecit Confusion Seizure Coma
Management of subdural empyema
Drain pus
Antimicrobial agents guided by microbiology of pus
What might be the function of a ventriculoperitoneal shunt or an external ventricular drain?
Monitor ICP or drain excess CSF
What most commonly colonises VPs and EVDs?
Coagulase negative staphylococci- normal skin flora
Rx of VP/EVD infection?
Device removal, IV Abx
