Brain abscess is a collection of pus that forms when an area of the brain is infected or hurt. Brain abscess should be treated as a medical emergency failing which can result in functioning of certain body parts or may lead to death. Brain abscess is often seen in men under 30 years of age followed by children between 4 and 7 years.
Symptoms of brain abscess
- Severe headache – the most common symptom seen in individuals suffering from brain abscess. Pain starts in the place of abscess.
- Nausea and vomiting – As the abscess increases, it occupies more space in the brain which in turn puts pressure on surrounding parts of the brain.
- Seizures – A seizure is usually the first sign of brain abscess.
- Fever
- Change in mental status of the individual. Often the person is confused, lethargic, unable to focus, respond etc. In severe cases of brain abscess, the person may go into coma.
Neurological symptoms in people suffering from brain abscess:
- Muscle weakness
- Paralysis on one side of the body or loss of function in body parts
- Problem forming sentences while speaking
- Stiff neck, back or shoulders
- Problems with vision
Note: If the symptoms worsen all of a sudden, there might be a possibility that the abscess has burst. This needs emergency medical attention.
Brain abscess causes
Brain abscess is most often caused by infection from bacteria or fungus. In some people, abscess can be a result of parasitic infection. The abscess formed due to infection usually consists of dead white blood cells, dead brain cells and the microbes that cause the infection. As the fluids of pus start forming, body develops an envelope sort of thing to contain the puss to protect the rest of the brain. When the infection becomes severe, the envelope breaks and the fluids leaks in to other parts of the brain disrupting the functioning of respective parts of the brain (and body). As the puss sack keeps growing, it occupies more space by squeezing other parts of the brain. In such a scenario, nausea and vomiting are a common symptom.
Wondering how the infection gets into the brain?
- Any infection from the body can get into the brain once it successfully crosses the blood-brain barrier. (More on blood-brain barrier soon!)
- Infection of the ear can also lead to infection of brain
- A severe injury to the head can lead to an infection in the brain
What is blood-brain barrier?
Blood-brain barrier is a protective network of blood vessels and cells that block certain components of blood to pass into the brain. For instance, when treating depression, a doctor prescribes SSRIs. These medications usually have hard time crossing the blood brain barrier to treat the mental condition of the patient. Sometimes, the infection from other parts of the body manages to get past the blood brain barrier and enters the brain.

Diagnosis of brain abscess
Diagnosis of brain abscess starts with a series of questions including the symptoms, the time of start, recent infection and travel history etc. Following tests may be required by the doctor:
- Blood test to check the levels of white blood cells. If the WBC count is higher than normal, that indicates that the body is fighting an infection.
- CT Scan or MRI scan of the brain may be required, if your doctor suspects that something might be wrong in the brain.
CT guided aspiration may be done to extract a little pus from the infected area and sent for further testing to determine the infection causing microbe.
Diagnosis of brain abscess
Diagnosis of brain abscess starts with a series of questions including the symptoms, the time of start, recent infection and travel history etc. Following tests may be required by the doctor:
- Blood test to check the levels of white blood cells. If the WBC count is higher than normal, that indicates that the body is fighting an infection.
- CT Scan or MRI scan of the brain may be required, if your doctor suspects that something might be wrong in the brain.
CT guided aspiration may be done to extract a little pus from the infected area and sent for further testing to determine the infection causing microbe.