Encephalitis is inflammation of the brain which is often a life-threatening. It usually begins with flu-like symptoms such as:
- high temperature (fever) of 38ºC (100.4ºF) or above
- headache
- nausea and vomiting
- joint pain
After this initial stage, more serious symptoms can begin to develop, which may include:
- changes in mental state, such as confusion, drowsiness or disorientation
- seizures (fits)
- changes in personality and behaviour
Other symptoms of encephalitis can include:
- sensitivity to bright lights (photophobia)
- inability to speak
- inability to control physical movements
- stiff neck
- hallucinations – seeing and hearing things that are not actually there
- loss of sensation in certain parts of the body
- partial or total vision loss
- involuntary eye movements, such as moving the eyes from side to side
- involuntary movements of the face, arms and legs
Some types of autoimmune encephalitis can cause changes to your mental health, such as
- anxiety
- unusual behaviours
- delusions – believing things that are obviously untrue
- paranoia – a belief that people are ‘out to get you’ and are actively plotting against you
When to seek medical advice
Flu-like symptoms that rapidly get worse and change a person’s mental state should be treated as a medical emergency. In such circumstances, you should dial 999 immediately and request an ambulance.
