NS Infection - Brain Abscess/Empyema & HIV Flashcards
Difference between brain abscess and empyema?
Abscess if localised pus in the brain
Empyema is usually a thin layer of pus between dura & Arachnoid
How does a brain abscess/empyema present?
- Fever
- Headache
- Focal Signs e.g. seizures or dysphasia or weakness
- Raised ICP (Papilloedema, depressed consciousness)
- ~Meningism with empyema
- Underlying source infection (Dental, ear, sinus)
Whats the DDX for a brain abscess?
Any other focal lesion e.g. tumour or subdural haematoma
Causes of Brain abscess/empyema?
- Adjacent infection (Dental, Ear, Sinus)
- Blood born infection (e.g. endocarditis)
- Neurosurgical procedures
- Penetrating head injuries
How do we approach a suspected brain abscess or empyema?
- CT (MRI is alternative)
- Investigate any source infection
- Blood culture
- Biopsy (Drainage) for culture & Sensitivity tests
Describe the bacteria in a brain abscess
Often mixtures of organisms:
- Staph aureus
- Streptococci - esp Strep constellatus, intermedius
- Anaerobes such as bacteroides
lots of others
We’ve investigated our brain abscess, our do we treat it?
- Surgical drainage if possible
IV Abx:
- Ceftriaxone (for Streptococci) - or other cephalosporin
- Metronidazole (for Anaerobes)
Patient’s with HIV can present with a lot of unusual Nervous conditions such as?
- Cerebral Toxoplasmosis
- Aseptic Meningitis/Encephalitis
- Cerebral Lymphoma
- Cerebral Abscess
- Cryptococcal Meningitis
- Dementia
- Leucoencephalopathy
How would we investigate a patient with CNS manifestations we suspect to be HIV related?
- India Ink for cryptococcal Antigen
- Toxoplasmosis Serology (IgG)
- PCR for JC virus, CMV & HIV
What brain infections are likely in HIV patients with a low CD4 count? (AIDS)
- Cryptococcus neoformans
- Toxoplasma gondii
- Progressive multifocal leukoencephalopathy (PML)
- Cytomegalovirus (CMV)
- HIV-encephalopathy (HIV-associated dementia)
