1) Encephalitis is an inflammation of the brain that is usually caused by a viral infection or the immune system mistakenly attacking brain tissue. 2) There are two main types - primary encephalitis occurs when a virus directly infects the brain, while secondary encephalitis occurs when an infection starts elsewhere and spreads to the brain. 3) Symptoms range from mild like fever and headache, to more severe such as confusion, seizures, and coma. Diagnosis involves tests of spinal fluid, imaging of the brain, and blood tests to identify the cause of infection or inflammation.

1. ENCEPHALITIS EXPLANATION

2. What is Encephalitis?
1.)Encephalitis is an acute inflammation (swelling) of the brain
usually resulting from either a viral infection or due to the body's
own immune system mistakenly attacking brain tissue.
2)The most common cause is a viral infection. The brain becomes
inflamed. Encephalitis is an inflammation of the brain tissue. The
most common cause is viral infections.
3) In rare cases it can be caused by bacteria or even fungi.

4. There are two main types of encephalitis:
primary and secondary.
 Primary encephalitis occurs when a virus directly infects the
brain and spinal cord.
 Secondary encephalitis occurs when an infection starts
elsewhere in the body and then travels to your brain.
 Encephalitis is a rare yet serious disease that can be life-
threatening. You should call your doctor immediately if you
have symptoms of encephalitis.

5. Primary encephalitis.
 This condition occurs when a virus or other agent directly infects the
brain.
 The infection may be concentrated in one area or widespread.
 A primary infection may be a reactivation of a virus that had been
inactive after a previous illness.
Secondary encephalitis.
 This condition results from a faulty immune system reaction to an
infection elsewhere in the body.
 Instead of attacking only the cells causing the infection, the immune
system also mistakenly attacks healthy cells in the brain.
 Also known as post-infection encephalitis, secondary encephalitis often
occurs two to three weeks after the initial infection.

6. Symptoms of encephalitis?
Mild symptoms include:
 fever
 headache
 vomiting
 stiff neck
 lethargy (exhaustion)

7. Severe symptoms include:
 fever of 103°F (39.4°C) or higher
 confusion
 drowsiness
 slower movements
 coma
 seizures
 irritability
 sensitivity to light
 Unconsciousness

8. 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

9. Causes 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 herpes virus typically travels through a nerve to the skin, where it causes
a cold sore. In rare cases, however, the virus travels to the brain.
 This form of encephalitis usually affects the temporal lobe, the part of the
brain that controls memory and speech.
 It can also affect the frontal lobe, the part that controls emotions and
behavior.
 Encephalitis caused by herpes is dangerous and can lead to severe brain
damage and death

10. Childhood viruses
Vaccines can prevent the childhood viruses that used
to cause encephalitis. Therefore, these types of
encephalitis are rare today. Some childhood viruses
that can cause encephalitis include:
• chicken pox (very rare)
• measles
• rubella

11. Arboviruses
• Arboviruses are viruses carried by insects. The type of arbovirus that’s
transmitted depends on the insect. Below are different 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 in the rural Midwest and southern states.
It’s generally a mild virus and causes few symptoms.
• West Nile virus is most often found in Africa and the Middle East.
However, it can occur in the United States. It’s usually relatively mild,
causing flu-like symptoms. However, it can be fatal among older adults
and people with weak immune systems.

12. • Colorado encephalitis (also called Colorado tick fever) is transmitted by
the female wood tick. It’s typically a mild disease, and most people will
recover quickly.
• Eastern equine encephalitis is spread by mosquitoes. It affects both
humans and horses. Although rare, it has a 33 percent mortality rate.
• Kyasanur forest disease is transmitted through tick bites. People can
also get it by drinking raw milk from goats, sheep, or cows. Hunters,
campers, and farmers are most at risk for getting this disease.

13. How is encephalitis diagnosed?
• Your doctor will first ask you about your symptoms. They may perform
the following tests if encephalitis is suspected.
Spinal tap or lumbar puncture
• In this procedure, your doctor will insert a needle into your lower back
to collect a sample of spinal fluid. They will test the sample for signs of
infection.
Brain imaging with CT scan or MRI
• CT scans and MRI detect changes in brain structure. They can rule out
other possible explanations for symptoms, such as a tumor or stroke.
Certain viruses have a tendency to affect certain areas of the brain.
Seeing what parts of your brain are affected can help determine what
type of virus you have.

14. Electroencephalograph (EEG)
• An EEG uses electrodes (small metal discs with wires) attached to the
scalp to record brain activity.
• An EEG does not 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 lead to seizures and coma in later stages.
• That's why the EEG is important in determining the areas of the brain that
are affected and the types of brain waves that occur in each area.

15. Blood tests
• A blood test can reveal signs of a viral infection. Blood tests are
rarely performed alone. They usually help diagnose encephalitis
along with other tests.
Brain biopsy
• In a brain biopsy, your doctor will remove small samples of brain
tissue to test for infection. This procedure is rarely 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

16. Lumbar puncture
• A lumbar puncture is a procedure to remove some fluid from
around the spinal cord (the nerves running up the spine) so it
can be checked for signs of encephalitis.
For the procedure:
• you lie on one side and bring your knees up towards your
chin
• local anaesthetic is used to numb your lower back
• a needle is inserted into the lower part of your spine and
a sample of fluid is removed
• The sample will be checked for signs of infection or a
problem with your immune system, which are the
main causes of encephalitis.

17. What is the long-term outlook for someone
with encephalitis?
• Your outlook will depend on the severity of the
inflammation.
• In mild cases of encephalitis, the inflammation will likely
resolve in a few days.
• For people who have severe cases it may require weeks or
months for them to get better.
• It can sometimes cause permanent brain damage or even
death.

18. People with encephalitis may also experience:
• paralysis
• loss of brain function
• problems with speech, behavior, memory, and balance
• Depending on the type and severity of encephalitis, it may be
necessary to receive additional therapy, including:
• physical therapy: to improve strength, coordination, balance, and
flexibility
• occupational therapy: to help redevelop everyday skills
• speech therapy: to help relearn muscle control needed for talking
• psychotherapy: to help with coping strategies, mood disorders, or
personality changes

19. FOODS
 Since encephalitis is a virus there are not that many
medications that can be prescribed.
 The best course of treatment is to get plenty of bed rest.
You should also drink plenty of fluids, such as water and
pure fruit juices.
 While infected with the disease your diet should consist of
fresh fruits and vegetables, as well as lean cuts of meat
and fish. You should avoid all unhealthy foods.

20. CASES IN INDIA

21. USA

22. Sex distribution in acute viral
encephalitis patients