Brain abscess notes
Here's what I studied =)
- Direct spread (Paranasal sinusitis, otitis media, mastoiditis, dental infection)
- Head trauma or surgical procedure
- Hematogenous spread (Pneumonia, endocarditis)
- MRSA (Head trauma, neurosurgical procedure)
- Headache > 75% patients
- Fever only in 50% patients (Important: Absence of fever should not exclude the diagnosis)
- Focal neurologic deficits > 60% patients
- Other symptoms - Papilledema, nausea, vomiting, drowsiness, confusion
Hemiparesis - Frontal lobe abscess
Dysphasia - Temporal lobe abscess
Nystagmus, ataxia - Cerebellar abscess
- MRI is better than CT.
- Ring enhancing lesion with surrounding edema on neuro imaging studies is seen.
- Most accurate: Brain biopsy
High yield: Biopsy is essential to distinguish brain abscess from cancer and also to determine the precise organism.
Don'ts: Do NOT do a LP. CSF analysis doesn't contribute to diagnosis or therapy. Increases the risk of herniation.
Extra: Abscesses due to Listeria have blood culture positive > 85% of the time.
- Brain tumors (Cancer can give fever)
- Empirical antibiotics should be modified after results of gram stain and culture.
- Surgical drainage.
- Prophylactic anticonvulsant therapy (High risk [>35%] of seizures)
- Glucocorticoids are reserved for substantial periabscess edema and mass effect due to increased ICP.
- Serial MRI or CT scan monthly to document resolution of abscess.