Encephalitis is the (acute) swelling/inflammation of the brain often as a result of illness or of injury. There are many causes for encephalitis, and it is a symptom of many different conditions such as rabies and meningitis. The symptoms of encephalitis itself are fever, acute headaches, malaise, depression, mania, hallucinations, seizures, memory problems, tremors, convulsions and eventually coma, breathing difficulties and death with the severity of the symptoms depending on the severity and duration of the encephalitis.
As mentioned there are many different causes of encephalitis and it is a symptom of many other medical conditions. These include for example viral conditions (viral encephalitis) and can be the result of an acute infection or as a combination of latent infections. One common cause is the herpes (HSV - herpes simplex virus) which can cause inflammation. Other causes are bacterial and these include things such as meningitis when it spreads to the brain, syphilis and rabies. Some parasitic and protozoal infections can also cause the condition, such as toxoplasmosis, primary amoebic meningoencephalitis and malaria. Lymme disease may also, but not always, result in encephalitis.
Should you feel the symptoms of encephalitis (headaches, fever, tiredness, depression, hallucinations etc) then you should consult a doctor who will consider this as a cause. They will note other symptoms that may point to the cause of the condition such as bites from bats which might indicate rabies. Another symptom of encephalitis might be a stiff neck which occurs due to the irritation of the meninges which cover the brain. Neurological examinations and brain imaging techniques may also help to identify encephalitis and to discover the severity of the condition.
Usually the treatment will depend on the cause and will be symptomatic. Antiviral agents may be used for viral infections such as herpes simplex virus, though these meet only limited success. Likewise other treatments may be more suitable for bacterial infection such as post-exposure prophylaxis for cases of rabies or in some cases penicillin. The sooner the problem is addressed the better the prognosis for treatment. Anticonvulsants will be used in order to prevent seizures, while sedatives might be used for irritability and restlessness and corticosteroids in order to reduce the inflammation.
In severe cases, it may be necessary to use supportive treatments such as mechanical ventilation in order to help breathing. In rare cases induced coma has been used in order to treat the condition while the patient is dormant.