About Brain Abscess
A brain abscess can be caused by bacteria, fungus and parasites. Infections of the face, ears, or sinuses may spread to the brain by direct extension through adjacent tissues. Infections in other body organs such as pneumonia, dental abscess or endocarditis, may spread through the blood stream and cause one or more brain abscesses. Occasionally, brain abscesses develop in patients following neurosurgical procedures, such as surgery for brain tumor.
Procedures, such as surgery for brain tumor. Patients who have weakened immune systems (immunocompromised) are at higher risk for brain abscesses. AIDS patients, cancer patients, and others with autoimmune diseases have a high predilection for developing fungal as well as other unusual infections of the brain.
Symptoms
Patients may complain of headaches, low-grade fever, neck stiffness, and nausea or vomiting. Some will present with seizures or mental status changes. Focal neurological problems, such as speech problems, weakness or numbness can be noted if the abscess involves critical areas of the brain. If the brain abscess has arisen from another infectious process, there may be symptoms suggestive of the primary infection, for example pneumonia.
Diagnosis
The MRI scan above shows severe contrast enhancing lesions suspicious for brain abscess. The diagnosis is usually made by a combination of the history, physical exam and brain imaging. MRI with and without contrast is the study of choice. Unlike other brain infections, a brain abscess is usually not diagnosed by CSF studies. A lumbar puncture may actually be contraindicated in these patients secondary to the mass effect the abscess has on the brain. If CSF is removed, the swollen brain can shift into small openings in the dura and skull causing neurological deterioration.
Treatment
Patients are usually hospitalized and treated with IV fluids. Intubation may be necessary if the patient is significantly lethargic or has difficulty breathing. The treatment of the cerebral abscess depends on the organism identified. If abscesses are small or multiple, stereotactic aspriration may be performed to obtain a sample of tissue. Once the organism is identified, long term intravenous antibiotics are used to treat the infection.
