Brain Abcess : Causes, Risk Factor, Diagnosis, Symptoms and Treatment

A brain abscess is a collection of pus, immune cells, and other material in the brain, usually from a bacterial or fungal infection. It is mostly formed by bacterial infection; a fungal infection can be caused in weak immune system.

• Brain abscess forms when fungi, viruses, or bacteria reach your brain through a wound in your head or an infection somewhere else in the body.
• Heart and lung infections are among the most common causes of brain abscesses.
• But brain abscesses can also begin from an ear or sinus infection, or even an abscessed tooth.
• It can occur in any age, but most frequent in ages above 60.

Causes of brain abscess:

• Brain abscesses commonly occur when bacteria or fungi infect part of the brain. As a result, swelling and irritation (inflammation) develop.
• Infected brain cells, white blood cells, live and dead bacteria or fungi collect in an area of the brain. Tissue forms around this area and creates a mass, or abscess.
• The germs that cause a brain abscess can reach the brain through the blood. Or, they enter the brain directly, such as during brain surgery. In rare cases, a brain abscess develops from an infection in the sinuses.
• The source of the infection is often not found. However, the most common source is a lung infection. Less often, a heart infection is the cause

Risk factors of brain abscess:

Certain risk factors which increases the chances of infection may include:

• A compromised immune system due to HIV or AIDS
• Cancer and other chronic illnesses
• Congenital heart disease
• Major head injury or skull fracture
• Meningitis
• Immunosuppressant drugs, such as those used in chemotherapy
• Chronic sinus or middle ear infections
• Certain birth defects allow the infection to reach brain more easily, such as tetralogy of fallot, which is a heart defect.   

Diagnosis of brain abscess:

Diagnosis of brain abscess may be done by certain methods, which include:

• Blood cultures- to know for infection in the blood
• Chest x-ray- To see any suspected infection in lungs
• Complete blood count (CBC)
• Head CT scan
• Electroencephalogram (EEG)-to test the electric impulses in the brain
• MRI of head
• Testing for the presence of antibodies to certain germs
• Lumbar puncture or spine tap- Taking a small amount of cerebral spinal fluid to see any further problems in brain other than infection

Symptoms of brain abscess:

Certain symptoms may include:

• Differences in mental processes, such as increased confusion, decreased responsiveness, and irritability
• Decreased speech
• Decreased sensation
• Decreased movement due to loss of muscle function
• Changes in vision
• Changes in personality or behaviour
• Vomiting
• Fever
• Chills
• Neck stiffness, especially when it occurs with fevers and chills
• Sensitivity to light

Treatments of brain abscess:

Brain abscess is a medical emergency; it should be treated immediately to prevent any further worsening condition, which may include:

Medication is the treatment procedure if certain abscess are:

• A small abscess (less than 2 cm)
• An abscess deep in the brain
• An abscess and meningitis
• Several abscesses (rare)
• Shunts in the brain for hydrocephalus (in some cases, the shunt may need to be removed temporarily or replaced)
• An infection called toxoplasmosis in a person with HIV/AIDS

Surgery is  done in certain cases:

• Increased pressure in the brain continues or gets worse
• The brain abscess does not get smaller after medicine
• The brain abscess contains gas (produced by some types of bacteria)
• The brain abscess might break open (rupture)
• The brain abscess is large (more than 2 cm)

Surgical technique is always avoided as it can bring certain complications