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.
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
- 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)
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 improve 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.
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
- Mood swings
- Lack of motivation or enthusiasm
- Poor short-term memory
- Poor concentration
Following encephalitis, a rest period lasting weeks or months is needed to allow the brain some time to make a recovery.