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. Brain abscesses are rare, but are more common in young school-aged children than in other ages.

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:

1. 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.

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

3. 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/screws that are placed around the head to hold the head and neck areas still; 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

• Immunosuppression. A state in which, due to genetic conditions or the use of certain powerful prescription medications that suppress the immune system, the body's ability to fight infection is impaired.

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

  • 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 resemble 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 invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.

• 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.

• Urine and stool tests

• Sputum culture. A diagnostic test performed on the material that is coughed up from the lungs and into the mouth. A sputum culture is often performed 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. 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).

Treatment for a brain abscess

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

• Your child's age, overall health, and medical history

• The extent of the condition

• Your child's tolerance for specific medications, procedures, or therapies

• Expectations for the course of condition

• Your opinion or preference

The key to treating a brain abscess is early detection and treatment. A child with a brain abscess requires immediate hospitalization, early antibiotic administration, possible surgery, and close monitoring.

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 is dependent on the severity of the brain abscess and the presence of other organ system problems that could affect the child. In severe cases, a breathing machine may be required 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 educates the family after hospitalization on how to best care for their child at home and outlines specific clinical problems that require immediate medical attention by his or her doctor. A child with a brain abscess requires frequent medical evaluations following hospitalization.