Accumulation of matter in the brain as a result of an infection, it is an accumulation of pus, immune cells, and other materials in the brain, in general, as a consequence of a fungal or bacterial infection. Abscesses usually occur when bacteria or fungi infect a part of the brain and become inflamed and swollen as a response. The brain cells that have been infected fungal bacteria and white blood cells accumulate in an area of the brain, which leads to tissue forming around that area forming a mass. While this immune response can protect the brain by blocking the infection, it can also harm more than benefit. The brain swells, and as the skull cannot expand, the mass puts pressure on the delicate tissue of the brain. The infected material can clog the cerebral blood vessels.
The microorganisms that cause a brain abscess usually reach the brain through the blood. In general, the source of the infection is not found, but the most frequent is the pulmonary and the least a heart infection. The microorganisms can also travel from a nearby infected area (mouth or ear) or enter the body when an injury occurs or in neurosurgery. In children with a congenital defect of the blood vessels or heart disease, infections can reach the brain from the teeth, intestines or other areas of the body.
Factors that increase the risk of brain abscess:
Chronic disease like cancer
Cardiac shunts from right to left in general as a consequence of congenital heart disease
Weakened immune system (AIDS)
Drugs that inhibit the immune system (chemotherapy)
Symptoms may manifest slowly, within two weeks or may occur suddenly and may include:
Reduction of sensitivity
Fever and chills
Difficulties in the language
Loss of muscle function, especially on one side
Changes in vision
reduction of movements
Aphasia (speech reduction)
Loss of coordination
Changes in the mental state:
Reduction of response capacity
Slowness in cognitive processes
A brain abscess is an emergency since intracranial pressure can cause death. Hospitalization is necessary until the patient stabilizes and in some cases, life support may be required. Immediate treatment is necessary when the abscess is injuring the brain tissue when pressed or if there is a large abscess swollen around it that increases the intracranial pressure. Antifungal medications may be prescribed if the infection is likely to be caused by a fungus.
Surgery is necessary when:
Intracranial pressure is prolonged or aggravated
Brain abscess contains gas (caused by some types of bacteria)
Brain abscess is not reduced after medication
Brain abscess can be broken
The surgical intervention consists in opening the skull and draining the brain. In general, laboratory tests are done to analyze the fluid, which can identify what is the cause of the infection. The surgery used depends on the size and depth of the abscess. The entire abscess can be removed if it is close to the surface and encapsulated in a sac. In case of deep abscesses, needle aspiration guided by a computed tomography or magnetic resonance may be necessary. During the performance of this procedure, medications can be injected directly into the mass. Other steroids and diuretics may be used to decrease cerebral edema.
A brain abscess is usually fatal without treatment. With it, the mortality rate ranges between 10 and 30%. The earlier the treatment is performed, the better. In some cases, prolonged neurological problems may occur after surgery.