What is Encephalitis?
Encephalitis is a condition in which the brain becomes inflamed, often leading to swelling. This swelling can disrupt brain function, leading to changes in thinking, behavior, and physical function. It can develop quickly and may become serious without prompt care.
Causes and risk factors:
- Viral infections (most common), including herpes simplex and mosquito-borne viruses
- Bacterial infections (less common)
- Tick-borne or animal-related infections
- Autoimmune conditions where the immune system attacks the brain
- Rarely, as a response related to certain cancers
Symptoms
Encephalitis often begins after a viral illness, such as a cold or stomach infection. Symptoms can vary depending on which part of the brain is affected.
Common symptoms include:
- Headache
- Fever or flu-like symptoms (fatigue, body aches)
- Sensitivity to light
- Stiff neck
- Drowsiness or unusual sleepiness
- Irritability or mood changes
- Confusion or trouble thinking clearly
- Seizures
- Nausea or vomiting
- Difficulty with balance or walking
Severe symptoms may include:
- Weakness or paralysis
- Trouble speaking or hearing
- Double vision
- Memory problems
- Loss of consciousness or coma
How is it diagnosed?
Healthcare providers begin with a physical exam and a review of symptoms and recent exposures, such as illness, travel, or insect bites.
To confirm the diagnosis, testing may include:
- Imaging scans like MRI or CT to look at the brain
- Blood tests to check for infection or immune activity
- Lumbar puncture (spinal tap) to analyze fluid around the brain and spinal cord
- EEG to measure brain activity
- Other lab tests to identify possible infections
In rare situations, additional monitoring or a biopsy may be needed.
How is it treated?
Encephalitis is usually treated in the hospital, where patients can be closely monitored.
Treatment may include:
- Antiviral medications if a virus is suspected
- Antibiotics, if a bacterial cause is identified
- Medications to reduce brain swelling
- Anti-seizure medications
- Treatments that calm the immune system in autoimmune cases
- Supportive care, such as fluids, oxygen, or breathing support
Early treatment is important to reduce complications.
Recovery expectations:
- Mild cases may improve fully with proper care
- More severe cases can lead to lasting effects, such as memory problems or seizures
- Rehabilitation therapies (physical, speech, or occupational) may help regain lost skills
