An initial assessment will be made based on your physical symptoms and recent medical history, such as whether you have had a recent infection or have a weakened immune system.
Blood tests
Blood tests will be carried out to check for the presence of infection. A high level of white blood cells in your blood indicates the presence of a serious infection.
Scans
If a brain abscess is suspected, the diagnosis can be confirmed using a CT (computerised tomography) scan or MRI (magnetic resonance imaging) scan. The high-definition images produced by these scans are able to detect the presence of an abscess.
For more information, see the Health A-Z topics on CT scans and MRI scans.
CT-guided aspiration
If an abscess is found, neurosurgeons (doctors who specialise in the treatment of the nervous system and brain) can use a CT scan to guide a needle to the site of the abscess and remove a sample of pus for further testing. This is known as CT-guided aspiration. The sample of pus should be able to indicate the type of germ that is causing the abscess.
Treatment with broad-spectrum antibiotics will usually begin as soon as possible, even before a CT-guided aspiration is carried out, because it can be dangerous to wait for the results.
Broad-spectrum antibiotics can be used against a wide range of bacteria. They will be used before a specific diagnosis is made because there is a high chance they will be effective if the infection is caused by bacteria.
If the test reveals that the abscess is being caused by a fungus, the treatment plan can be changed and antifungal medication can be given.
