Encephalitis is a rare condition that causes inflammation of the brain. It is most commonly caused by an infection or virus that invades the brain, but it can also be caused by bacteria or parasites. In very rare cases, encephalitis can be caused by an injury to the brain, an adverse reaction to drugs or medications, or the body's immune system mistakenly attacks the brain.
If a virus, or bacteria caused by parasites, enters the bloodstream, it can be carried to the brain where an inflammatory action or encephalitis can occur. This can lead to swelling of brain tissue, bleeding within the brain, and even permanent brain damage. People with weak immune systems, children and the elderly are more susceptible to encephalitis, although it can affect anyone.
The symptoms of encephalitis can vary widely, and sometimes no symptoms will appear. In severe cases, symptoms may include difficulty walking or standing, clumsiness, headache, neck pain, stiff neck, fatigue, nausea, vomiting, irritability, drowsiness, mental confusion, aversion to light, and in severe cases rare, convulsions or coma. Symptoms of encephalitis in babies are more difficult to recognize, but can include squinting or turning away from light, and the body becoming weak or limping.
The cause of encephalitis is often a mystery unless a widespread outbreak is documented. In some cases, insects carrying a virus will infect a community and the cause can be identified. In isolated cases of the condition, it is more difficult to determine a cause. Although viruses and bacteria are thought to account for the majority of cases, specific germs have been found in less than fifty percent of encephalitis patients.
There are more than 100 different germs that are believed to cause encephalitis. Some of the most common include herpes simplex virus, enteroviruses that are spread through feces, and arboviruses that are spread through insect bites. Encephalitis is also sometimes caused by the body's overreaction to common infections like herpes simplex, measles, and even the flu.
To diagnose a patient with encephalitis, a lumbar puncture, or lumbar puncture, is performed by inserting a needle into the lower back and taking a sample of fluid from the spinal column. The fluid is then tested for viruses, bacteria, or other substances that may be associated with encephalitis. A biopsy, where a small piece of brain tissue is removed and tested for viruses, may also be performed if the doctor deems it necessary for a diagnosis.
If a patient is positively diagnosed with encephalitis, antibiotic treatment is usually prescribed immediately, especially if the cause is unknown. The acute phase, or the time when the brain is swollen, lasts up to two weeks, and symptoms may gradually or suddenly dissipate after this time. Further treatment depends on the cause of the condition and may include antiviral medications, steroids to reduce swelling, and narcotics to relieve pain. Once the acute phase is over, the focus shifts to rehabilitation and treatment of brain damage or any other persistent problems.