Home Disorders Brain Disorders   Encephalitis



Encephalitis means an inflammation of the brain. This inflammation of the brain caused by the viral and bacterial infection. Both the brain and spinal cord are involved, encephalomyelitis disorder. Encephalitis ranges from mild to severe which may results in permanent neurological damage and death.

Encephalitis is a rare disease. It occurs in approximately 0.5 per 100,000 individuals. It is most common among in children and people with weakened immune systems. Some people who have encephalitis are left with eternal brain damage.

Types of Encephalitis

  • Primary Encephalitis - This type of encephalitis results from viral infection of the brain and spinal cord. Primary encephalitis occurs in sporadic or occur in many people at the same time in the same area. The most common type of sporadic infection is herpes simplex encephalitis which causes by the herpesvirus.
  • Secondary Encephalitis - This type of encephalitis develops as a complication of a viral infection. Viruses can become reactive when the immune system is suppressed by other conditions. Infections causes secondary encephalitis such as i influenza, chickenpox etc.

Causes of Encephalitis

The main cause of encephalitis is  a dozen viruses that can spread by either human to human contact or by animal bites. Encephalitis  occur with several common viral infections of childhood. The viruses are chickenpox, measles, mumps, epstein-barr virus, HIV etc.

  • Herpes simplex encephalitis is a virus which is responsible for 10% of all encephalitis cases and it mainly causes to sporadic, fatal encephalitis.
  • Arboviruses are viruses which spread by insects, and cause St. Louis encephalitis.
  • Milder forms of encephalitis causes childhood illnesses including measles, mumps, chickenpox, rubella.
  • Varicella-zoster virus is responsible for chickenpox and shingles which cause encephalitis in adults and children.
  • The brain tissue swells which causes destruction of nerve cells, bleeding within the brain and brain damage.

Symptoms of Encephalitis

  • Fever
  • Headache
  • Confusion
  • Seizures
  • Poor appetite
  • Stiff neck
  • Nausea
  • Loss of energy
  • Vomiting
  • Drowsiness

Diagnosis of Encephalitis

Diagnosis of encephalitis includes careful examination to determine possible exposure to viral sources.  These tests can help to confirm the diagnosis and rule out other disorders.

  • Blood tests
  • Electroencephalogram (EEG).
  • CT and MRI scans.
  • Cerebrospinal fluid analysis
  • In some cases A brain biopsy recommended
  • A lumbar puncture test

Treatment of Encephalitis

A treatment for encephalitis is depend on the cause and symptoms. The symptoms of encephalitis is treated with a number of different drugs.

  • Bacterial encephalitis is treated with antibiotics while viral encephalitis is treated with antiviral drugs like acyclovir, ganciclovir, foscarnet, ribovarin, and AZT etc.
  • Drugs like dexamethasone injections used given to reduce the inflammation and swelling of the brain.
  • The seizures require treatment with anti-convulsant medications.
  • Anti inflammatory drugs help to reduce swelling and pressure within your skull.

Preventions of Encephalitis

You can prevent Encephalitis by avoiding infection.

  • Wear protective clothing like long sleeves and long pants.
  • Vaccination is help to prevent some a form of viral encephalitis.
  • Use insect repellent.
  • Control mosquitoes which reduce the chance of some infections that can lead to encephalitis.
  • By spraying insecticides

What is the prognosis of Encephalitis?

In many cases of encephalitis are serene and recovery is generally quick. Mild encephalitis generally leaves no residual neurological problems. Approximately 10% of patients of encephalitis die from their infections and complications such as secondary infection.  In some cases permanent impairment or death is possible.

Some forms of encephalitis have more severe courses including herpes encephalitis in which mortality is 15-20% with treatment, and 70-80% without.  In eastern equine encephalitis antiviral treatment is ineffective.