A brain abscess is a swelling in the brain which is filled with pus and usually occurs when bacteria or fungi enter the brain tissue after an infection or severe head injury.

The risk of developing a brain abscess is extremely low, but when it does occur, it is a life threatening condition and should be diagnosed and treated as soon as possible.

Symptoms of a Brain Abscess

The symptoms of a brain abscess may develop quickly or slowly but can include any or all of the following:-

• In adults:
  • Headache – which is often severe, located in a single section of the head and can’t be relieved by painkillers
  • Changes in mental state – such as confusion and or irritability
  • Problems with nerve function – such as muscle weakness, slurred speech or paralysis on one side of the body
  • A high temperature (fever) of 38C (100.4F) or above
  • Seizures (fits)
  • Lethargy
  • Personality changes
  • Nausea and vomiting
  • Stiff neck
  • Poor mental focus
  • Poor responsiveness
  • Slow thought processes
  • Changes in vision – such as blurring, greying of vision or double vision (if the abscess is putting pressure on the optic nerve).

• In babies and younger children:
  • Fever
  • A full or bulging fontanelle (soft spot located on the top of the head)
  • Sleepiness or less alert than usual
  • Increased irritability
  • High-pitched cry
  • Poor feeding
  • Projectile vomiting
  • Seizures

• In older children:
  • Fever
  • Complaints of severe headaches
  • Nausea and vomiting
  • Changes in personality or behavior
  • Changes in speech
  • Problems walking
  • Increased movement in the arms or legs (spasticity)
  • Seizures

Your child is more likely to develop a brain abscess if he or she has:

• Heart disease that is present from birth (congenital)
• Meningitis
• Long-term (chronic) middle ear and sinus infections
• Dental or jaw infections
• Infections of the face or scalp
• Head injury or skull fracture
• Traction. This is a medical device that uses pins or screws placed around the head to hold the head and neck areas still. It is used in a child who has a broken neck or for surgeries that need the head and neck to stay still.
• Shunt infections. Shunts are devices used to drain extra cerebral spinal fluid.
• Diabetes

• Weakened immune system. This is when your child’s body is less able to fight infection. Certain medicines and health conditions such as HIV can weaken the immune system.

When to Seek Medical Advice

Any symptoms that suggest a problem with the brain and nervous system should be treated as a medical emergency and you should dial 999 for an ambulance immediately. These include:

• Slurred speech
• Muscle weakness or paralysis
• Seizures occurring in a person with no previous history of seizures

Causes of a Brain Abscess

There are three main ways in which a brain abscess can develop:

1. An infection in another part of the skull – such as an ear infection, sinusitis or dental infection, which can spread directly to the brain.
2. An infection in another part of the body, for example, the infection that causes pneumonia spreading into the brain via the blood
3. Trauma, such as a severe head injury, that cracks the skull to allow bacteria or fungi to enter the brain.

Diagnosis of a Brain Abscess

A medical history will be taken as well as the following:

• Blood tests
• A CT scan (computerised tomography scan) a series of x-rays used to produce a detailed image of the inside of your body
• An MRI scan which uses magnetic fields and radio waves to produce a detailed image of the inside of your body.

If an abscess is found, a procedure known as CT-guided aspiration may be used to remove a sample of pus for testing. This involves using a CT scan to guide a needle to the site of the abscess.

Treating a Brain Abscess

A brain abscess is regarded as a medical emergency. Swelling caused by the abscess can disrupt the blood and oxygen supply to the brain.  There’s also a risk of the abscess bursting (rupturing).

If left untreated, a brain abscess can cause permanent brain damage and could be fatal.

A brain abscess is usually treated using a combination of:

• Medication (antibiotics or antifungals)
• Surgery – either draining the pus through a hole in the skull (simple aspiration) or opening the skull and removing the abscess entirely (craniotomy)

Complications of a Brain Abscess

• A reoccurring abscess
• Brain damage – mild to moderate brain damage often improves with time, but severe brain damage is likely to be permanent. Brain damage is a greater risk if diagnosis and treatment is delayed.
• Epilepsy (repeated seizures / fits)
• Meningitis – a life threatening infection of the protective membranes around the brain, which requires urgent treatment (more common in children)