Encephalitis is a rare, serious brain infection with many possible causes. Its physical symptoms typically ease with hospital care and medications. But its effects on brain functioning can linger, affecting everyday life.


What is encephalitis?

Encephalitis is a brain inflammation that occurs due to an infection such as a virus or bacteria, medication or immune system malfunction. Encephalitis is a rare, often serious condition that requires timely care.


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How does encephalitis affect my body?

Encephalitis causes physical symptoms like fever, headaches and neck pain. It can also affect brain (cognitive) functioning, leading to confusion and behavior changes. In some cases, cognitive encephalitis symptoms linger long after physical symptoms go away.

How is encephalitis different from meningitis?

Both conditions are uncommon but severe.

Some important differences are that:

  • Encephalitis occurs in the brain.
  • Meningitis affects the meninges. This delicate layer of tissue protects the brain and spinal cord.

Symptoms and Causes

What causes encephalitis?

The type of encephalitis you experience depends on the cause. And there are many causes, including:

  • Viruses: Infections from herpes, enteroviruses, human immunodeficiency virus (HIV), West Nile and tick-borne viruses lead to viral encephalitis. This is the most common cause.
  • Problem with the immune system: The immune system can mistakenly attack the brain, causing autoimmune encephalitis.
  • Bacteria and parasites: On rare occasions, these germs can cause bacterial encephalitis.

What are encephalitis symptoms?

You’ll likely experience physical and neurologic symptoms.

Physical symptoms may include:

Neurologic encephalitis symptoms may include:

  • Behavior changes.
  • Confusion.
  • Difficulty speaking or moving.
  • Loss of consciousness.
  • Memory issues.
  • Seizures.
  • Sensitivity to light.

Diagnosis and Tests

When should I see a healthcare provider?

The sooner you receive care, the better your chances of recovery. For mild encephalitis symptoms, your first step may be going to an urgent care center. For severe issues, like seizures and loss of consciousness, the best place to go for care is an emergency room.

How is encephalitis diagnosed?

Healthcare providers take many steps to diagnose brain infections.

Your care may include:

  • Physical exam to learn more about your symptoms.
  • Neurologic exam to assess brain functioning.
  • Lab tests and imaging studies, which help confirm or rule out encephalitis.

What types of tests might I need?

Testing helps healthcare providers:

  • Assess encephalitis symptoms.
  • Determine how severe it is.
  • Identify the type of encephalitis (autoimmune, viral or bacterial).

Tests you may need include:

  • Lumbar puncture (spinal tap), which involves taking a sample of spinal fluid and examining it in a lab.
  • Blood tests, which assess organ functioning and check for specific types of bacteria.
  • Imaging studies, such as a CT scan, MRI and MEG test. These tests show signs of tissue damage. They can also detect issues like tumors and brain bleeds.

Management and Treatment

How is encephalitis treated?

The brain infection treatments you need depend on the type of encephalitis and how severe it is.

You may need:

  • Antibiotics to treat bacterial infections.
  • Antiviral medications for viral infections.
  • Antiseizure medicines if you are having seizures.
  • Breathing assistance, including supplemental oxygen or a breathing machine (mechanical ventilation).
  • Immunomodulators, which are medications that quiet immune system attacks.
  • Intravenous (IV) fluids to keep you hydrated.
  • Steroids, which reduce swelling and brain pressure.
  • Tube feeding to deliver nutrition if you are unconscious.

How soon will I feel better?

Treatments for autoimmune and viral encephalitis may start working in as little as a few days. But it can take a while for the brain to heal. Some people experience lasting cognitive effects that require rehabilitative therapies and lifestyle changes.


How can I prevent encephalitis?

You can stay current with vaccines for diseases that cause encephalitis, such as the measles, mumps and rubella (MMR) injection.

Are there other vaccines that can help me?

Traveling to certain countries can expose you to germs and diseases that are not common in the U.S. Some of these diseases can cause brain infections.

You may benefit from vaccines for:

Outlook / Prognosis

What will my life be like after encephalitis?

The impact of autoimmune and viral encephalitis on brain functioning differs from person to person. Some people make a complete recovery.

Others experience long-lasting encephalitis symptoms that include:

  • Balance and coordination issues.
  • Difficulty concentrating.
  • Fatigue.
  • Hearing loss.
  • Mood swings and other behavior changes.
  • Memory issues.
  • Speech and language problems.
  • Changes in personality, such as being quick to anger.

Are these symptoms permanent?

For some people, they are. Rehabilitation can help you cope with changes in your abilities. It also enables you to regain as much functioning as possible.

How can rehabilitation help me?

Rehabilitation includes different types of therapies that help you learn how to:

  • Complete everyday tasks, like getting dressed.
  • Communicate, even if speaking becomes difficult.
  • Make lists and use other planning techniques.
  • Manage money and other resources.
  • Regain balance and coordination with special exercises and assistive devices.

Living With

What else can I do to make daily life a little easier?

You can maximize your well-being by paying careful attention to:

  • Nutrition: What you eat can affect how you feel. Make sure you are eating foods that have a lot of vitamins and nutrients. Meals should include fruits, grains, lean meats, vegetables and dairy products.
  • Pacing: You may only be able to tolerate short periods of activity. Consider scheduling tasks on a calendar with rest periods before and after. This approach can help you avoid trying to do too much at once.
  • Sleep: It’s natural to feel tired while you are recovering. But lingering cognitive symptoms can also affect sleep quality. Following a consistent nighttime schedule and relaxing before bedtime can help.

A note from Cleveland Clinic

Encephalitis is a brain infection that requires care in a hospital. After the infection goes away, you may experience lingering symptoms that affect brain functioning. Achieving your full recovery potential takes time. In some cases, months or years. Rehabilitation and good self-care can maximize your abilities and quality of life.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 04/30/2021.

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