overview

Encephalitis is an inflammation of the brain tissue. the foremost common cause is viral infections. In rare cases it are often caused by bacteria or maybe fungi.

There are two main sorts of encephalitis: primary and secondary. Primary encephalitis occurs when an epidemic directly infects the brain and medulla spinalis . Secondary encephalitis occurs when an infection starts elsewhere within the body then travels to your brain.

Encephalitis may be a rare yet serious disease which will be life-threatening. you ought to call your doctor immediately if you’ve got symptoms of encephalitis.

symptoms of encephalitis

The symptoms of encephalitis can range from mild to severe.

Mild symptoms include:

fever
headache
vomiting
stiff neck
lethargy (exhaustion)
Severe symptoms include:

fever of 103°F (39.4°C) or higher
confusion
drowsiness
hallucinations
slower movements
coma
seizures
irritability
sensitivity to light
unconsciousness
Infants and young children show different symptoms. Call a doctor immediately if your child is experiencing any of the following:

vomiting
bulging fontanel (soft spot in the scalp)
constant crying
body stiffness
poor appetite

causes of encephalitis

Many different viruses can cause encephalitis. It’s helpful to categorize the potential causes into three groups: common viruses, childhood viruses, and arboviruses.

Common viruses
The most common virus that causes encephalitis in developed countries is herpes simplex. The herpes typically travels through a nerve to the skin, where it causes a chilly sore. In rare cases, however, the virus travels to the brain.

This form of encephalitis usually affects the lobe , the a part of the brain that controls memory and speech. It also can affect the lobe , the part that controls emotions and behavior. Encephalitis caused by herpes is dangerous and may cause severe brain damage and death.

Other common viruses which will cause encephalitis include:

mumps
Epstein-Barr virus
HIV
cytomegalovirus
Childhood viruses
Vaccines can prevent the childhood viruses that wont to cause encephalitis. Therefore, these sorts of encephalitis are rare today. Some childhood viruses which will cause encephalitis include:

chicken pox (very rare)
measles
rubella
Arboviruses
Arboviruses are viruses carried by insects. the sort of arbovirus that’s transmitted depends on the insect. Below are differing types of arboviruses:

California encephalitis (also called La Crosse encephalitis) is transmitted through mosquito bites and mainly affects children. It causes few to no symptoms.
St. Louis encephalitis occurs within the rural Midwest and southern states. It’s generally a light virus and causes few symptoms.
West Nile virus is most frequently found in Africa and therefore the Middle East . However, it can occur within the us . It’s usually relatively mild, causing flu-like symptoms. However, it are often fatal among older adults and other people with weak immune systems.
Colorado encephalitis (also called Colorado tick fever) is transmitted by the feminine American dog tick . It’s typically a light disease, and most of the people will recover quickly.
Eastern equine encephalomyelitis is spread by mosquitoes. It affects both humans and horses. Although rare, it’s a 33 percent mortality rateTrusted Source.
Kyasanur forest disease is transmitted through tick bites. People also can catch on by drinking milk from goats, sheep, or cows. Hunters, campers, and farmers are most in danger for getting this disease.

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MBBS, MD – Pediatrics,
DM – Neurology Neurologist 6 Years Experience Overall

How is encephalitis diagnosed?

Your doctor will first ask you about your symptoms. they’ll perform the subsequent tests if encephalitis is suspected.

Spinal tap or spinal puncture
In this procedure, your doctor will insert a needle into your lower back to gather a sample of cerebrospinal fluid . they’re going to test the sample for signs of infection.

Brain imaging with CT scan or MRI
CT scans and MRI detect changes in brain structure. they will rule out other possible explanations for symptoms, like a tumor or stroke. Certain viruses have a bent to affect certain areas of the brain. Seeing what parts of your brain are affected can help determine what sort of virus you’ve got .

Electroencephalograph (EEG)
An EEG uses electrodes (small metal discs with wires) attached to the scalp to record brain activity. An EEG doesn’t detect the virus that causes encephalitis, but certain patterns on the EEG may alert your neurologist to an infectious source of your symptoms. Encephalitis can cause seizures and coma in later stages. That’s why the EEG is vital in determining the areas of the brain that are affected and therefore the sorts of brain waves that occur in each area.

Blood tests
A biopsy can reveal signs of a virus infection . Blood tests are rarely performed alone. they typically help diagnose encephalitis along side other tests.

Brain biopsy
In a brain biopsy, your doctor will remove small samples of brain tissue to check for infection. This procedure is never performed because there’s a high risk of complications. It’s usually only done if doctors can’t determine the cause the brain swelling or if treatment isn’t working.

How is encephalitis treated?

Anti-viral medications can help treat herpes encephalitis. However, they aren’t effective in treating other forms of encephalitis. Instead, treatment often focuses on relieving symptoms. These treatments may include:

rest
pain killers
corticosteroids (to reduce brain inflammation)
mechanical ventilation (to help with breathing)
lukewarm sponge baths
anticonvulsants (to prevent or stop seizures)
sedatives (for restlessness, aggressiveness, and irritability)
fluids (sometimes through an IV)
You may need to be hospitalized during treatment, especially with brain swelling and seizures.

What are the risk factors for encephalitis?

The groups most at risk of encephalitis are:

older adults
children under the age of 1
people with weak immune systems
You may also have a higher risk of getting encephalitis if you live in an area where mosquitos or ticks are common. Mosquitos and ticks can carry viruses that cause encephalitis. You’re more likely to get encephalitis in the summer or fall when these insects are most active.

Although the MMR (measles, mumps, rubella) vaccine has a long history of being safe and effective, in rare cases it has caused encephalitis. Approximately 1 in 3 million children who receive the vaccine develop encephalitis. However, the statistics are much more striking for children who don’t receive the vaccine. Rates of encephalitis in the days before routine vaccination reached as high as 1 in 1,000. In other words, encephalitis was roughly 3,000 times more common before vaccination was available.