Symptoms of encephalitis generally appear within 2 days to 2 weeks of introduction to the virus. They vary widely depending on cause and severity. In mild cases, flu like symptoms is seen. But in severe cases, symptoms include:

• Behavioral and personality changes
• Sensitivity to light
• Fever
• Headache
• Vomiting
• Muscle weakness; unsteadiness standing up or trouble walking
• Sluggishness and reduced consciousness
• Seizures — uncommon with West Nile virus
• Memory loss
• Stiff neck and back — accompanied by fever and headache would indicate meningitis
• Confusion
• Speech, hearing, and vision problems
• Muscle weakness
• Seizures
• Tremors
• Partial paralysis
• Loss of consciousness
• Coma(in severe cases)

Baby’s body may become weak or shamble and they may peep or turn away from a light source. Full to bursting in the soft spots (fontanels) of the skull is observed in infants.

Treatment:-

Cases with mild encephalitis can be treated with

• Rest
• A healthy diet, with plenty of liquids
• Using acetaminophen (Tylenol and others) to relieve headaches and fever

Bacterial encephalitis can be treated with antibiotics while viral encephalitis due to herpes simplex respond to some antiviral drugs such as acyclovir, ganciclovir, foscarnet, ribovarin, and AZT, so treated with such drugs. Arboviral encephalitis has no cure and can be cured by palliative care only, such as by intravenous fluids which helps reduce dehydration. Diuretics like furosemide and mannitol help decrease intracranial pressure and benzodiazepines like lorazepam prevent seizures. Anti-inflammatory drugs, for example corticosteroids, assist to reduce swelling and pressure within the skull. Anticonvulsants are used to prevent seizures. Manny other drugs and antibiotics are used to cure encephalitis and patient is to be kept under medical examination and kept in ICU. Prevention is better than cure, so we should take preventions and try that this disease dose not attacks us.

TYPES OF ENCEPHALITIES

Primary encephalitis- It involves direct viral infection on brain and spinal cord. It usually happen in isolated cases (sporadic) or may arise in many people at the similar time in the same area (epidemic). They carry an elevated risk for serious neurological damage and death and may occur in infants if the virus is passed from the mother to the infant at the time birth.

Secondary encephalitis- In this viral infection first occurs somewhere else in body and then travels to brain or due to reactivation of a latent virus. Here viruses become reactive when the immune system is suppressed.

Causes

The viruses that lead to infectious encephalitis can be kept into three categories:

Common viruses: Viruses involved are herpes simplex virus (HSV) type 1 and type2 or the Epstein Barr virus (EBV). Widely spread in large population.

Childhood viruses: Responsible for causing childhood infections, like mumps, measles and rubella.

Arboviruses: Are transmitted by blood sucking insects, such as mosquitoes and ticks. Some examples of arboviruses are Japanese encephalitis, tick-borne encephalitis and West Nile encephalitis, Eastern equine encephalitis, Western equine encephalitis’s, Louis encephalitis,La Crosse encephalitis. Mosquitoes act as vectors for the spread of encephalitis from small creatures like birds and rodents to humans. Some Ticks also act as a vector and carry such viruses that cause brain inflammation, and causes Russian spring-summer encephalitis which is more common in China, Korea, and the eastern areas of Russia.

The blood brain barrier of brain protects it from viral infection n other toxic materials, it is a thick membrane that acts as a barrier and filters out impurities from blood prior to allowing it to go into the brain. But due to some reasons these viruses passes the blood brain barrier and infect the tissues of brain. After passing the blood brain barrier, virus enters the blood cells and damage them leading to a loss of normal brain function. If not treated, encephalitis may result in coma and finally death.

Post infectious encephalitis is a rare viral infection complication, which occurs following vaccine-preventable childhood viral infections, including: measles, mumps or chickenpox, germane measles (rubella).  In this case encephalitis occurs due to hypersensitivity, an overreaction of immune system to a foreign substance.

It may be caused by a bacterial infection, spreading directly to the brain (primary encephalitis), or may be a due to complications of an existing infectious disease syphilis (secondary encephalitis).