Children's Health and Wellness

Brain Abscess

What is a brain abscess?

A brain abscess is an infection in the brain that is encapsulated (confined within its own area) and localized to one or more areas inside of the brain. This condition may cause problems with the brain and spinal cord function.

What causes a brain abscess?

The more common causes of a brain abscess include viruses, fungi, and bacteria, with bacteria being the most common and much more significant cause. There are three ways a virus or bacteria can enter the body and infect the brain:

  • Infection is spread from another area of infection in the body, usually from a nearby site. Typically, this might be an ear infection, sinus infection, or dental infection.

  • Infection is spread through the blood stream from the lung or chest area.

  • Viral or bacterial germs enter directly into the brain through an open wound in the head.

  • Risk factors for developing a brain abscess include the following:

    • Congenital (present at birth) heart disease

    • Meningitis

    • Chronic middle ear and sinus infections

    • Dental or jaw infections

    • Infections of the face or scalp

    • Head injury or skull fracture

    • Traction. A medical device that uses pins or screws that are placed around the head to hold the head and neck areas still. It is used in patients with broken necks or for specific surgeries that require the head and neck to be immobilized.

    • Shunt (devices used to drain excess amounts of cerebral spinal fluid) infections

    • Diabetes

    • Weakened immune system. This is when the body's ability to fight infection is impaired. Health conditions such as HIV, and certain medications can weaken the immune system. 

    What are the symptoms of a brain abscess?

    The following are the most common symptoms of a brain abscess. However, each child may experience symptoms differently. Symptoms may include:

    • In babies and younger children:

      • Fever

      • A full or bulging fontanelle (soft spot located on the top of the head)

      • Sleepiness or less alert than usual

      • Increased irritability

      • High-pitched cry

      • Poor feeding

      • Projectile vomiting

      • Headache

      • Seizures

    • In older children:

      • Fever

      • Complaints of severe headaches

      • Nausea and vomiting

      • Changes in personality or behavior

      • Changes in speech

      • Problems walking

      • Increased movement in the arms or legs (spasticity)

      • Seizures

    The symptoms of a brain abscess may look like other conditions or medical problems. Always consult your child's doctor for a diagnosis.

    How is a brain abscess diagnosed?

    The diagnosis of a brain abscess is made after the sudden or gradual onset of specific signs and symptoms and after diagnostic testing. During the physical examination, your child's doctor will obtain a complete medical history of your child. He or she may also ask if there is a family history of any medical problems. A measurement of the circumference of your child's head is taken and compared to a scale that can identify normal and abnormal ranges. As the infection grows and becomes bigger, it can push on the brain and may cause increased pressure inside of the head, which, in turn, can cause symptoms in your child.

    Diagnostic tests that may be performed to confirm the diagnosis of brain abscess may include the following:

    • Blood tests

    • X-ray. A diagnostic test which uses radiation beams to produce images of internal tissues, bones, and organs onto film. A skull X-ray would be unlikely to show an abscess but can show fractures that might lead to an abscess.

    • Magnetic resonance imaging (MRI). A diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body. Intravenous (IV) contrast agents may be given during the scan to better highlight the abscess.

    • Computed tomography scan (also called a CT or CAT scan). A diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce horizontal, or axial, images (often called slices) of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general X-rays but are not as detailed as MRI. Often, contrast is needed to evaluate an abscess.

    • Urine and stool tests

    • Sputum culture. A diagnostic test done on the material that is coughed up from the lungs and into the mouth. A sputum culture is often done to determine if an infection is present.

    • Lumbar puncture (spinal tap). A special needle is placed into the lower back, into the spinal canal. This is the area around the spinal cord. The pressure in the spinal canal and brain can then be measured. A small amount of cerebral spinal fluid (CSF) can be removed and sent for testing to determine if there is an infection or other problems. It is important to determine what kind of infection may be causing the abscess because treatment differs depending on the cause. CSF is the fluid that bathes your child's brain and spinal cord. If there is significant brain swelling or shift in the brain tissue, a lumbar puncture may be deferred or not done at all (due to concerns about brain herniation, which is a process in which the brain is compressed and then shifted due to very high pressures). If it is safe to do a lumbar puncture, it can help ensure that the appropriate treatment is started early for the best outcome.

    Treatment for a brain abscess

    Specific treatment for a brain abscess will be determined by your child's doctor based on:

    • The specific bacteria, fungus, virus, or parasite causing the infection

    • How old your child is

    • His or her overall health and medical history

    • How sick he or she is

    • How well your child can handle specific medications, procedures, or therapies

    • Your opinion or preference

    The key to treating a brain abscess is early detection and treatment. A child with a brain abscess needs to be hospitalized right away, started on antibiotics, and watched closely. Surgery may be needed.

    The goal of treatment is to reduce the pressure in the head and to properly drain the infection. Medications are used to control the infection, seizures, fever, and/or other conditions that may be present.

    The extent of the problem depends on the severity of the brain abscess and whether other organ system problems are present. In severe cases, a breathing machine may be needed to help the child breathe easier.

    As the child recovers, physical, occupational, or speech therapy may be needed to help the child regain muscle strength and/or speech skills.

    The health care team will help you learn how to best care for your child at home and outlines specific clinical problems that require immediate medical attention. Frequent medical evaluations will be needed following treatment.

    Print Source: Central nervous system infection in the pediatric population. Narayan Sahu, R. Journal of Pediatric Neurosciences. 2009, is. 4, ed. 1, pp. 20-24.
    Print Source: Pathogenesis, Clinical Manifestations, and Diagnosis of Brain Abscess, Up To Date
    Print Source: Treatment and Prognosis of Bacterial Brain Abscess, Up To Date
    Online Source: Acute Meningitis and Encephalitis: Brain Abscess, Harrison's Manual of Medicine http://harrisons.unboundmedicine.com
    Online Source: Journal of Neurosurgery Onlinehttp://thejns.org/doi/full/10.3171/foc/2008/24/6/e6
    Online Source: The Merck Manual http://www.merckmanuals.com/professional/neurologic_disorders/brain_infections/brain_abscess.html
    Online Editor: Metzger, Geri K.
    Online Medical Reviewer: MMI board-certified, academically affiliated clinician
    Online Medical Reviewer: Turley, Ray, BSN, MSN
    Date Last Reviewed: 12/15/2014
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