Table of contents

Brain abscess

What's new

Added 2023 ESCMID guidelines for the diagnosis and management of brain abscess.



Brain abscess is a focal infection within the brain parenchyma, characterized by a localized area of cerebritis that eventually transforms into a collection of pus within a well-vascularized capsule.
The pathophysiology of a brain abscess typically involves bacterial infection, which can arise from contiguous sites such as the sinuses, middle ear, or mastoid or through hematogenous spread from a distant site. Common causative pathogens include Bacteroides species, K. pneumoniae, Viridans streptococci, and S. aureus.
The incidence of brain abscess is estimated at 0.4-0.9 per 100,000 person-years.
Disease course
Clinically, patients with a brain abscess may present with headache, fever, neurological deficits, altered mental status, and signs of increased ICP. The clinical presentation can vary depending on the location and size of the abscess and the patient's immune status.
Prognosis and risk of recurrence
The prognosis of brain abscess has improved over time due to advancements in neurosurgical techniques, cranial imaging, and antimicrobial regimens.


Key sources

The following summarized guidelines for the evaluation and management of brain abscess are prepared by our editorial team based on guidelines from the European Society for Microbiology and Infectious Diseases (ESCMID 2024), the American Heart Association (AHA 2015), and the Infectious Diseases Society of America (IDSA 2011)....
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Diagnostic investigations

Brain imaging
As per ESCMID 2024 guidelines:
Obtain brain MRI, including DWI/apparent diffusion coefficient and T1-weighted imaging, with and without gadolinium in patients with suspected brain abscess.
Obtain contrast-enhanced CT if MRI is not available.
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  • Laboratory tests

Medical management

Antimicrobial therapy, timing: as per ESCMID 2024 guidelines, Consider withholding antimicrobials until aspiration or excision of brain abscess in patients without severe disease if neurosurgery can be performed within a reasonable time, preferably within 24 hours of radiological diagnosis.

More topics in this section

  • Antimicrobial therapy (choice of regimen)

  • Antimicrobial therapy (duration)

  • Antimicrobial therapy (consolidation)

  • Corticosteroids

  • Seizure prophylaxis

Surgical interventions

Indications for surgery: as per ESCMID 2024 guidelines, Perform neurosurgical aspiration or excision as soon as possible and whenever feasible in all patients with brain abscess, except for toxoplasmosis.

Specific circumstances

Patients with IE-related brain abscess: as per AHA 2015 guidelines, Administer nafcillin instead of cefazolin in patients with MSSA infective endocarditis complicated with brain abscess. Administer vancomycin in patients with nafcillin intolerance.