What is Encephalitis?

By Dr. Ananya Mandal, MDReviewed by Sally Robertson, B.Sc.

Encephalitis is a relatively rare condition that causes inflammation of the brain. Initial symptoms usually include high temperature, headache and joint pain but as the infection progresses, more dangerous symptoms may start to develop and include the following:

• Seizures
• Altered mental state such as confusion, drowsiness and disorientation
• Personality and behavioural changes

Flu-like symptoms that suddenly start to worsen should be treated as urgent and medical attention should be sought immediately.

Causes of encephalitis

The type of encephalitis a person has depends on the condition’s cause. The different types of encephalitis include:

Infectious encephalitis

This is a direct result of an infection in the brain, which is usually caused by a virus.

Post-infectious encephalitis

The encephalitis may also occur as an immune response to an infection that has already subsided. The initial infection may have occurred days, weeks or even months previously.

Autoimmune encephalitis

Sometimes, the inflammation is a result of an autoimmune reaction to the presence of tissue that is not infected.

Chronic encephalitis

In some health conditions such as HIV, the inflammation may build up slowly, over time.

Diagnosis and treatment

Diagnosis is based on tests used to distinguish encephalitis form other conditions that affect the brain such as meningitis. The tests that may be performed include commuted tomography (CT) and magnetic resonance imaging (MRI) scans; spinal tap and electroencephalogram (EEG).

Treatment needs to be urgent and is usually administered in a hospital. The earlier the condition is treated, the more likely a positive outcome is for the patient. Depending on the type of encephalitis a patient has, the treatment may be in the form of antiviral drugs, steroid injections or immunosuppressant therapy.

Sources                            

1. http://www.nhs.uk/Conditions/Encephalitis/Pages/Introduction.aspx
2. https://www.vdh.virginia.gov/epidemiology/epidemiology-fact-sheets/encephalitis/
3. https://www.idsociety.org/
4. http://www.benthamscience.com/

Further Reading

• All Encephalitis Content
• What can Aedes mosquitos transmit?
• Autoimmune Encephalitis Classification
• Autoimmune encephalitis
• Autoimmune encephalitis Diagnosis