St. Luke's Hospital
Located in Chesterfield, MO
Main Number: 314-434-1500
Emergency Dept: 314-205-6990 Patient Billing: 888-924-9200
Find a Physician Payment Options Locations & Directions
Follow us on: facebook twitter Mobile Email Page Email Page Print Page Print Page Increase Font Size Decrease Font Size Font Size
Meet the Doctor
Spirit of Women
Community Health Needs Assessment
Home > Health Information

Multimedia Encyclopedia


    Brain abscess

    Abscess - brain; Cerebral abscess; CNS abscess

    A brain abscess is a collection of pus, immune cells, and other material in the brain, usually from a bacterial or fungal infection.


    Brain abscesses commonly occur when bacteria or fungi infect part of the brain. Swelling and irritation (inflammation) develop in response to this infection. Infected brain cells, white blood cells, live and dead bacteria, and fungi collect in an area of the brain. Tissue forms around this area and creates a mass.

    While this immune response can protect the brain by isolating the infection, it can also do more harm than good. The brain swells. Because the skull cannot expand, the mass may put pressure on delicate brain tissue. Infected material can block the blood vessels of the brain.

    The germs that cause a brain abscess can reach the brain through the blood. The source of the infection is often not found. However, the most common source is a lung infection. Less often, a heart infection is the cause. Germs may also travel from a nearby infected area (for example, an ear infection or a tooth abscess) or enter the body during an injury (such as a gun or knife wound) or neurosurgery.

    In children with congenitalheart disease or a blood vessel birth defect, such as those with Tetralogy of Fallot, infections are more able to reach the brain from the intestines, teeth, or other body areas.

    The following raise your risk of a brain abscess:

    • A weakened immune system (such as in AIDS patients)
    • Chronic disease, such as cancer
    • Drugs that suppress the immune system (corticosteroids or chemotherapy)
    • Right-to-left heart shunts, usually the result of congenital heart disease


    Symptoms may develop slowly, over a period of 2 weeks, or they may develop suddenly. They may include:

    • Changes in mental status
      • Confusion
      • Decreasing responsiveness
      • Drowsiness
      • Eventual coma
      • Inattention
      • Irritability
      • Slow thought processes
    • Decreased movement
    • Decreased sensation
    • Decreased speech (aphasia)
    • Fever and chills
    • Headache
    • Language difficulties
    • Loss of coordination
    • Loss of muscle function, typically on one side
    • Seizures
    • Stiff neck
    • Vision changes
    • Vomiting

    Exams and Tests

    A brain and nervous system (neurological) exam will usually show signs ofincreased intracranial pressure and problems with brain function.

    Tests to diagnose a brain abscess may include:

    • Blood cultures
    • Chest x-ray
    • Complete blood count (CBC)
    • Head CT scan
    • Electroencephalogram (EEG)
    • MRI of head
    • Testing for the presence of antibodies to organisms such as Toxoplasma gondii and Taenia solium

    A needle biopsy is usually performed to identify the cause of the infection.


    A brain abscess is a medical emergency. Pressure inside the skull may become high enough to be life threatening. You will need to stay in the hospital until the condition is stable. Some people may need life support.

    Medication, not surgery, is recommended if you have:

    • Several abscesses (rare)
    • A small abscess (less than 2 cm)
    • An abscess deep in the brain
    • An abscess and meningitis
    • Shunts in the brain for hydrocephalus (in some cases the shunt may need to be removed temporarily or replaced)
    • Toxoplasma gondii infection in a person with HIV

    Antibiotics will be prescribed. Antibiotics that work against a number of different bacteria (broad spectrum antibiotics) are most commonly used. You may be prescribed several different types of antibiotics to make sure treatment works.

    Antifungal medications may also be prescribed if the infection is likely caused by a fungus.

    Immediate treatment may be needed if an abscess is injuring brain tissue by pressing on it, or there is a large abscess with a large amount of swelling around that it is raising pressure in the brain.

    Surgery is needed if :

    • Increased pressure in the brain continues or gets worse
    • The brain abscess does not get smaller after medication
    • The brain abscess contains gas (produced by some types of bacteria)
    • The brain abscess might break open (rupture)

    Surgery consists of opening the skull, exposing the brain, and draining the abscess. Laboratory tests are often done to examine the fluid. This can help identify what is causing the infection, so that more appropriate antibiotics or antifungal drugs can be prescribed.

    The surgical procedure used depends on the size and depth of the abscess. The entire abscess may be removed (excised) if it is near the surface and enclosed in a sac.

    Needle aspiration guided by CT or MRI scan may be needed for a deep abscess. During this procedure, medications may be injected directly into the mass.

    Certain diuretics and steroids may also be used to reduce swelling of the brain.

    Outlook (Prognosis)

    If untreated, a brain abscess is almost always deadly. With treatment, the death rate is about 10 - 30%. The earlier treatment is received, the better.

    Some patients may have long-term neurological problems after surgery.

    Possible Complications

    • Brain damage
    • Meningitis that is severe and life threatening
    • Return (recurrence) of infection
    • Seizures

    When to Contact a Medical Professional

    Go to a hospital emergency room or call the local emergency number (such as 911) if you have symptoms of a brain abscess.


    You can reduce the risk of developing a brain abscess by treating any disorders that can cause them. Have a follow-up examination after infections are treated.

    Some people, including those with certain heart disorders, may receive antibiotics before dental or urological procedures to help reduce the risk of infection.


    Nath A, Berger J. Brain abscess and parameningeal infections. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 421.

    Tunkel AR. Brain abscess. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 88.


    • Amebic brain abscess


    • Brain


      • Amebic brain abscess


      • Brain


      A Closer Look

        Talking to your MD

          Self Care

            Tests for Brain abscess

              Review Date: 10/6/2012

              Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.

              The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

              A.D.A.M. content is best viewed in IE9 or above, Fire Fox and chrome browser.

              Back  |  Top
              About Us
              Contact Us
              Locations & Directions
              Quality Reports
              Annual Reports
              Honors & Awards
              Community Health Needs

              Brain & Spine
              Sleep Medicine
              Urgent Care
              Women's Services
              All Services
              Patients & Visitors
              Locations & Directions
              Find a Physician
              Tour St. Luke's
              Patient & Visitor Information
              Contact Us
              Payment Options
              Financial Assistance
              Send a Card
              Mammogram Appointments
              Health Tools
              My Personal Health
              Spirit of Women
              Health Information & Tools
              Clinical Trials
              Employer Programs -
              Passport to Wellness

              Classes & Events
              Classes & Events
              Spirit of Women
              Donate & Volunteer
              Giving Opportunities
              Physicians & Employees
              For Physicians
              Remote Access
              Medical Residency Information
              Pharmacy Residency Information
              Physician CPOE Training
              St. Luke's Hospital - 232 South Woods Mill Road - Chesterfield, MO 63017 Main Number: 314-434-1500 Emergency Dept: 314-205-6990 Patient Billing: 888-924-9200
              Copyright © St. Luke's Hospital Website Terms and Conditions  |  Privacy Policy  |  Notice of Privacy Practices PDF  |  Patient Rights PDF Sitemap St. Luke's Mobile