Brain Abscess

What is a brain abscess?

A brain abscess is a collection of pus and other materials in your brain. An infection usually causes an abscess to develop.

When an infection targets part of your brain, inflammation happens as your body attempts to fight it. Waste from your immune system fighting the infection (including dead cells, bacteria or fungi) collects in an area of your brain. Tissue grows around the collection of waste material (pus) to form an abscess.

The abscess can swell and put pressure on your brain. This is a medical emergency and it can be life-threatening if left untreated.

You may hear your healthcare provider refer to a brain abscess as a cerebral abscess.

How common are brain abscesses?

Brain abscesses aren’t common. In the U.S., an estimated 1,500 to 2,500 cases happen each year.

What are the symptoms of a brain abscess?

Brain abscess symptoms include:

• A headache.
• Cognitive changes (confusion, difficulty thinking or processing information).
• Numbness, weakness or paralysis in part of your body.
• Sensation (feeling) changes.
• Speech and language difficulty.
• Vision changes.
• Fever.
• Seizures.
• Nausea and vomiting.
• Stiff neck.

Symptoms can happen suddenly or develop over several days to a couple of weeks. If you experience any of these symptoms, visit the emergency room immediately.

What causes a brain abscess?

A bacterial or fungal infection causes brain abscesses. Germs reach your brain through your blood, sinuses, an injury or surgery.

The most common pathogens that cause infection are:

• Staphylococcus.
• Streptococcus.

What are the risk factors for a brain abscess?

You may be more at risk of developing a brain abscess if you:

• Have a condition that weakens your immune system.
• Have cancer.
• Have a congenital heart disease.
• Take immunosuppressant medications (like corticosteroids or chemotherapy).

What are the complications of a brain abscess?

Brain abscess complications are life-threatening. They include:

• Brain swelling (cerebral edema).
• Abscess breaks open (rupture).
• Meningitis.
• Brain damage.
• Recurring (returning) abscesses.
• Coma.

How is a brain abscess diagnosed?

A healthcare provider will diagnose a brain abscess after a neurological exam and testing. This exam will show that you have increased pressure within your skull and, as a result, your brain isn’t functioning as expected.

To confirm a diagnosis, your provider will offer tests like:

• Blood tests (blood culture and complete blood count).
• Imaging tests (MRI and/or a CT scan).
• Electroencephalogram (EEG).

A needle biopsy can identify the cause and type of infection to help your provider treat it.

How is a brain abscess treated?

A brain abscess is a medical emergency that requires immediate attention. Treatment for a brain abscess includes:

• Medications: You’ll receive antibiotics or antifungal medications to treat the abscess. You’ll need to take antibiotics for at least four to eight weeks. You may also need water pills to reduce fluid in your body, antiseizure medications for seizures or steroids to decrease swelling.
• Surgery: A surgeon will open your skull and either drain the abscess or remove it. Your surgeon will send a sample of the abscess fluid to a lab to determine what caused it. You’ll need to take antibiotics or antifungal medications when the lab identifies the cause after surgery.
• Needle aspiration: Imaging tests, like an MRI or CT scan, help your surgeon reach abscesses deep within your brain. Your surgeon will use a needle to aspirate the abscess content and occasionally inject medications into the abscess to shrink it.

A healthcare provider will consider medications if:

• The abscess is less than 2 centimeters in size.
• The abscess is deep within your brain.
• You have meningitis or toxoplasmosis.
• You have a shunt in your brain. (Your provider may remove and replace it.)
• You have more than one abscess (rare).

Your provider may consider surgery if:

• The abscess is bigger than 2 centimeters.
• You have increased pressure on your brain that gets worse.
• Antibiotics or antifungal medications don’t shrink the abscess size.
• The abscess contains gas made by certain types of bacteria.
• The abscess is at risk of breaking open (rupture).

Treatment for a brain abscess takes place in a hospital setting. You’ll need to stay in the hospital for several days after treatment to make sure the abscess goes away and doesn’t cause complications. In some cases, life support is necessary after a severe brain abscess.

Can a brain abscess be prevented?

You can’t prevent all cases of brain abscesses. But you can take steps to reduce your risk by:

• Taking care of yourself to prevent infection, like washing your hands with soap and water before properly caring for wounds or surgical sites.
• Taking antibiotics as directed. You may need to take antibiotics before certain procedures (like dental procedures) to prevent infections.
• Getting treatment for any type of infection as soon as possible. Any delay can increase your risk of complications.

What’s the outlook for a brain abscess?

Quick treatment at the first sign of a brain abscess can lead to a better outcome. Brain abscesses are deadly if left untreated.

You may experience long-term issues that affect your nervous system following treatment for a brain abscess like seizures, difficulty with movement or personality changes, for example. Rehabilitation can help you recover or gain back some lost skills caused by the abscess.

Can you fully recover from a brain abscess?

Yes, it’s possible to fully recover after a brain abscess. This varies for each person and long-term complications may arise, depending on your situation.

What is the survival rate for a brain abscess?

Between 10% and 30% of all brain abscess cases are deadly. An early diagnosis and treatment lead to an improved survival rate.

When should I see a healthcare provider?

Contact a healthcare provider if you have symptoms of an infection like a fever and swelling.

Contact 911 (or your local emergency services number) or visit the emergency room right away if you have symptoms of a brain abscess.

What questions should I ask my healthcare provider?

• What caused the abscess?
• What type of treatment do you recommend?
• Are there side effects of treatment?
• Is there any permanent brain damage after having an abscess?
• How do I take care of myself once I leave the hospital?