Brain abscess is a potentially life-threatening condition, with clinical and radiological presentation similar to central nervous system tumour. Early recognition is required for optimal outcome.
Lesions may be single or multi-focal. Aetiological agents may be bacterial, fungal, and parasitic.
Treatments include appropriate antimicrobial agents, support in an intensive care unit, and possible surgical evacuation. Surgery involves either image-guided aspiration or craniotomy with resection of the abscess cavity.
Patients must be followed up with serial imaging until their lesions have completely resolved.
Prognosis is most closely related to the patient's neurological status at presentation.
Brain abscess is a suppurative collection of microbes (most often bacterial, fungal, or parasitic) within a gliotic capsule occurring within the brain parenchyma. Lesions may be single or multi-focal.
History and exam
Key diagnostic factors
- presence of risk factors
- male sex
- age <30 years
- cranial nerve palsy
- positive Kernig or Brudzinski sign
- increased head circumference (infants)
- bulging fontanelles (infants)
Other diagnostic factors
- neurological deficit
- otitis media
- dental procedure/infection
- recent neurosurgery
- congenital heart disease
- diverticular disease
- hereditary haemorrhagic telangiectasia or arteriovenous malformation
- diabetes mellitus
- HIV or immunocompromise
- intravenous drug use
- chronic granulomatous disease
- birth prematurity
- cystic fibrosis
1st investigations to order
- serum erythrocyte sedimentation rate (ESR)
- serum CRP
- serum PT and PTT
- blood culture
- serum toxoplasma titre
- MRI with contrast
- CT head with and without contrast
- ultrasound head (infants)
Investigations to consider
- magnetic resonance spectroscopy (MRS)
- lumbar puncture (LP) with cerebrospinal fluid (CSF) analysis
- CT chest, abdomen, and pelvis
- bone scan
presumed brain abscess
suspected or confirmed bacterial aetiology
confirmed fungal aetiology
suspected or confirmed parasitic aetiology
cryptogenic brain abscess
Walter A. Hall, MD, MBA
Department of Neurosurgery
SUNY Upstate Medical University
WAH is an author of a number of references cited in this topic.
Dr Walter A. Hall would like to gratefully acknowledge Dr Peter D. Kim, a previous contributor to this topic. PDK declares that he has no competing interests.
Stephen Haines, MD
Professor and Head
Department of Neurosurgery
University of Minnesota
SH and WAH were colleagues on a faculty of the University of Minnesota between 1991 and 1997 and again between 2004 and 2006. They have coauthored articles on neurosurgical infection.
Sabrina Ravaglia, MD, PhD
Department of Neurological Sciences
Institute of Neurology C. Mondino
SR declares that she has no competing interests.
- Primary central nervous system neoplasm
- Metastatic lesion
- Recurrent tumour/radiation necrosis in a post-surgical patient
- Anaerobic infections (individual fields): central nervous system infections (brain abscess, subdural abscess, epidural abscess and bacterial meningitis)
- Log in or subscribe to access all of BMJ Best Practice
Use of this content is subject to our disclaimer