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Conditions | Treatments | Infections
Brain Abscess
What is a Brain Abscess?
A brain abscess is a serious disorder that occurs when micro-organisms, such as bacteria or fungi enter the brain.
An abscess is formed when bacteria or fungi, along with infected cells and pus, mass together in one area of the brain. This mass is then joined by white blood cells that have been trying to fight the infection. The body's immune system responds to such an infection by creating a membrane around this infected portion of the brain, which in turn creates an abscess.
The swelling inside the brain caused by a developing abscess can put harmful pressure on delicate brain tissue and block blood vessels. If left untreated, abscesses can cause permanent brain damage, seizures or death.
Most brain abscesses occur when infection spreads to the brain from elsewhere in the body, such as the ears or from a head injury or following surgery.
Treatment
Brain abscesses are a medical emergency because they can raise the pressure on the brain to a point that may be fatal. Medication is usually the first line of treatment if:
- the abscess is small
- there is more than one abscess
- the abscess is situated deep within the brain
- the abscess is accompanied by meningitis
- surgery would be dangerous due to an underlying condition.
For a bacterial infection a large dosage of antibiotic medication is injected directly into a vein, such as Penicillin or Metronidazole. Alternatively, if a fungal infection is suspected then antifungal medications will also be given.
Surgery is an option if:
- antibiotic and antifungal medications don't work
- the pressure inside the brain is rising, or
- the abscess may burst and spill fluid into the rest of the brain.
Surgery
Surgery is carried out to open up an abscess and drain it. At this stage, it is useful to take a sample of the fluid drained, to test it and make sure the correct antibiotic or antifungal medications are being given.
If the abscess is near the surface it may be possible to remove the mass of infected pus and cells. If it is deep in the brain, this may be drained using a needle guided by a CT or MRI scan. Alternatively, antibiotics or antifungals may be injected directly into the abscess.
If the infection has spread from elsewhere in the body, such as the ear or lungs, it is necessary to also treat that site to prevent further infection or re-infection.
In some cases, corticosteroid drugs such as dexamethasone are used to ease the swelling and reduce intracranial pressure (pressure inside the skull).
Meningitis
What is Meningitis?
Meningitis is an infection of the meninges; which are protective membranes that surround the brain and spinal cord. Infection can cause the meninges to become inflamed and swollen, which can then damage nerves and the brain.
This condition can cause symptoms such as a severe headache, vomiting, high fever, stiff neck and sensitivity to light. Many of those affected also develop a distinctive skin rash.
Meningitis can be caused by a virus, such as the herpes simplex or bacteria, such as Streptococcus Pneumoniae, which usually lives harmlessly in the mouth and throat.
Bacterial meningitis is extremely serious and should be treated as a medical emergency as if left untreated it can cause severe damage to the brain and infect the blood (septicaemia), leading to shock and death.
Symptoms
The symptoms of bacterial meningitis usually begin abruptly and the patient can deteriorate rapidly. Symptoms include:
- severe headache
- fever
- vomiting
- drowsiness
- confusion
- seizures or fits
- intolerance of bright light (photophobia)
- stiff neck
- blotchy red skin rash which will not fade or change colour when a glass is placed against it.
Treatment
Treatment requires a transfer to an intensive care unit so that urgent investigations can be carried out whilst the body's functions are supported and antibiotics to treat infection and steroids to reduce inflammation are urgently administered.
Diagnostic tests for meningitis include:
- blood test - to check for bacteria or viruses,
- CT Scan - in order to assess the level of pressure on the brain
- lumbar puncture - taking a sample of cerebrospinal fluid (CSF) from the base of the spine and checking it for the presence of bacteria or viruses.
If it is proven that a bacteria has entered the blood, this can introduce toxins that kill healthy tissue. If this damage is severe, tissue will die and become gangrenous. Gangrenous tissue will need to be surgically removed. In the most severe cases, it may be necessary to amputate a whole body part, such as a finger, toe, or limb.
Most people treated early enough, will make a partial recover within 10-14 days, although it may be several weeks or months before they recover fully.
Possible brain related complications include:
- loss of hearing; this may be partial or total
- problems with memory and concentration
- problems with co-ordination and balance
- learning difficulties - this could be temporary or permanent
- epilepsy (see the 'related articles' section for more information on epilepsy)
- cerebral palsy (see the 'related articles' section for more information on cerebral palsy)
- speech problems
- loss of vision; this may be partial or total.
Encephalitis
What is Encephalitis?
Encephalitis is inflammation (swelling) of the brain tissue. It is caused either by viral infection or by an autoimmune disease. An autoimmune disease is when your immune system tries to fight off an infection but attacks parts of your body at the same time.
Encephalitis is more serious than meningitis, because it affects the brain itself. If the meninges are inflamed as well as the brain, the condition is called meningoencephalitis.
Some types of encephalitis can be mild and cause almost no symptoms, or cause a general feeling of being unwell accompanied by a fever. But other cases can be very serious and life threatening.
Symptoms
Early signs of encephalitis can develop in a few hours or over a few of days and can first appear as flu-like or virus type symptoms. However, in some cases, encephalitis may progress and become fatal. Encephalitis can affect almost any brain function, but the most common symptoms are:
- Severe headache.
- Fever, nausea.
- Vomiting.
- Drowsiness or confusion.
- Sensitive to bright lights.
- Memory loss.
- Unable to speak.
- Unable to control movement properly.
- Weakness of one or more parts of the body.
- Behaviour that is out of character.
- A change to any of the senses, e.g. touch, taste, smell, sight, hearing, stiff neck and back.
- Muscle weakness.
- Seizures (fits).
- Coma.
Treatment
In severe cases of encephalitis, patients may be admitted to intensive care so that any swelling in the brain can be more easily monitored and treated.
Acyclovir is typically administered used for viral encephalitis caused by the herpes-simplex virus. This drug is injected directly into the vein and if given early enough, can drastically improved the outlook in cases of herpes simplex encephalitis, although it is not as effective against other viruses.
In combination with Acycovir, drugs which help stop or prevent seizures (anti-convulsants) may also be given.
Corticosteroids can also be given to reduce inflammation of the brain as well as antibiotics to prevent or treat further infection complications developing.
Complications
Many people who have encephalitis make a full recovery but sometimes the brain has been permanently damaged (acquired brain injury).
Some of the complications include:
- Problems with balance.
- Weakness in part or parts of the body.
- Loss of control of movement.
- Loss of sensitivity to touch, taste, hearing, sight and smell.
- Slurred speech.
- Epileptic seizures (fits.
- Prolonged headache.
- Dizziness.
- Nausea
- Fatigue.
- Mood swings.
- Depression.
- Anxiety.
- Lack of motivation or enthusiasm.
- Poor short-term memory.
- Poor concentrate.
Following encephalitis, a rest period lasting weeks or months is needed to allow the brain some time to make a recovery.
