Brain Abscess in Emergency Medicine Follow-up

Updated: May 18, 2017
  • Author: Naomi George, MD; Chief Editor: Jeter (Jay) Pritchard Taylor, III, MD  more...
  • Print

Further Outpatient Care

Serial neuroimaging, either with CT or MRI, is typically recommended in order to follow treatment successfully to resolution of the abscess. Management may vary from weekly to monthly reimaging, depending on local practice patterns, as well as the patient’s course and symptomatic resolution. Enhancement of the lesion on neuroimaging may persist for months. Data on the precise interval for when to obtain reimaging studies are currently insufficient. In some patients, brain abscess fails to respond to antimicrobial therapy, while in others the response is not durable and the abscess reaccumulates; in these instances, reaspiration may be necessary. [82]


Further Inpatient Care

Despite considerable reductions in morbidity and mortality, brain abscess is a serious infection with potentially profound prognostic implications. Modern medical care of these patients often requires a swift, multidisciplinary approach. [82]

Initial management steps include confirmation of the size, location, and number of intracranial abscesses using CT with intravenous contrast, MRI, or both.

The decision to surgically manage the disease may vary with the characteristics of the abscess, and numerous practices are used. Typically, abscesses larger than 2.5 cm are excised or aspirated, often during emergent surgery. Patients in the early cerebritis stage or those with abscesses that are smaller than 2.5 cm may undergo aspiration for diagnosis only. Some neurosurgeons may prefer complete evacuation of the abscess capsule, while others may plan to reaspirate the lesions. [2, 40, 71]

Stereotactic CT or MRI-guided needle aspiration is a key procedure in facilitating expedient identification of the pathogen and may be a preferable approach compared with open craniotomy, with benefits of reduced morbidity and mortality. [88] Culture data collected during aspiration are beneficial for targeting and narrowing antimicrobial regimens.

Empiric intravenous antibiotics given for several days have an unclear effect on the success of brain abscess aspiration culture data. A major trial looking at the use of antibiotic therapy for up to 10 days prior to aspiration showed that this practice does not alter culture growth. [43] However, a second large study showed that approximately 40% of abscess cultures had no growth after empiric antibiotic therapy. [16]

The duration of intravenous antibiotic treatment is frequently 4-8 weeks or longer, with subsequent transition to oral antibiotics for another 4-8 weeks in order to ensure complete resolution and prevent relapse. [89]

A small body of literature on the effects of hyperbaric oxygen therapy as adjunctive therapy for brain abscess exists. Primary outcomes include reduction in length of stay and decreased duration of antibiotics therapy; however, at this time, evidence is insufficient. [90]



These patients frequently require neurosurgical management; thus, prompt transfer to a neurosurgical-capable hospital is appropriate if unavailable at the initial treating facility. Patients may also require ICU level of care, which is another indication for transfer.



Complications of brain abscess may be localized or global and include persistent weakness, aphasia, or cognitive impairment, as well as life-threatening complications such as herniation or intraventricular abscess rupture.

Brain herniation is frequently secondary to increased intracranial pressure from profound periabscess edema. [37]

Rupture of abscess into ventricles or subarachnoid space is a complication that is often lethal. High-risk features for this complication include an abscess that is deep seated, multiloculated, and/or close to the ventricular wall. [40]

Morbidity, including persistent neurologic sequelae such as focal deficits, seizures, and headache, occurs in approximately 50% of patients. [1, 9, 12]



The mortality rate of brain abscess has decreased to 15% in most developed countries, while mortality in resource-poor settings remains higher. [82] One of the most important factors in prognosis is the availability of healthcare resources. Mortality rates among immunocompromised patients are higher, despite appropriate surgical and medical therapy. [91] If immunosuppressive agents can be reduced, the chance of a positive outcome is improved. [1]

Key prognostic factors include associated with improved prognosis include the following:

  • Young age

  • Absence of severe neurologic defect on initial presentation. [13, 22]

  • Absence of neurologic deterioration during initial presentation [43]

  • Absence of comorbid disease [2, 13]

Worse prognosis of brain abscess is associated with the following:

  • Advanced age

  • Hematogenous spread [92]

  • Immunosuppression [92]

  • Evidence of intraventricular rupture [41]

  • Evidence of herniation on initial presentation [93]

  • Evidence of altered sensorium on initial presentation [16]

  • Severity of abscess and abscess location on initial neuroimaging [94]

  • Delay in diagnosis or definitive surgical intervention [71]

  • Certain pathogens, including gram-negative bacteria, [26] nocardial abscess, [95] or aspergillosis [87] portend a worse prognosis and higher mortality rates, particularly in immunocompromised patients


Patient Education

For excellent patient education resources, visit eMedicineHealth's Infections Center and Brain and Nervous System Center. Also, see eMedicineHealth's patient education articles Antibiotics and Brain Infection.