What is herpes encephalitis?
Herpes encephalitis is an uncommon but life-threatening problem caused by infection with the herpes virus. Encephalitis is an irritation or infection of the brain and central nervous system.
How does it occur?
The herpes virus usually causes a skin infection. It causes painful blisters that last for several days. The blisters may start as cold sores or fever blisters around the mouth, or they may start as sores in the genital or buttocks area. The virus can be spread from the blisters to other parts of the body and to other people.
There are several ways the virus might infect the brain and nervous system.
In between outbreaks on the skin, the herpes virus lives in nerve cells close to the spinal column. The virus may spread from these areas into the spinal fluid that cushions the brain and spinal cord.
The herpes virus may get into the central nervous system through herpes infections in the head and neck, including the ears. Many people have herpes infections inside their noses or inside their ears. These areas are separated from the central nervous system by very thin bones and membranes, which the virus can pass through.
The virus may spread to a newborn during delivery if the mother has herpes sores in the genital area. When this happens, the baby may have a total body herpes infection, including the central nervous system.
What are the symptoms?
The symptoms of herpes encephalitis are similar to the symptoms of meningitis, a stroke, or epilepsy: They may change from mild to severe within several days or even several hours.
At first the infection may cause flulike symptoms, including fever and muscle aches, especially headache.
There can be personality changes, confusion, hallucinations, and memory problems. Someone who is developing encephalitis is often not able to talk.
The infection may then cause a gradual decrease in awareness. There may be disorientation, confusion, and seizures. Coma may follow.
If you think you or someone else may have encephalitis, it is very important to contact your healthcare provider right away.
How is it diagnosed?
The diagnosis can be difficult. Because herpes encephalitis is rare and can look like more common emergency medical problems, such as a stroke, your medical history is very important. Your provider will want to know your medical history, including:
any history of herpes infections
when and how long you have had symptoms
other health problems you have that might make it harder for the body to fight infection, such as cancer, diabetes, or autoimmune diseases.
You will have a physical exam.
Lab and X-ray exams may include:
blood tests to look for signs of infection
spinal tap (lumbar puncture), which means a sample of spinal fluid is tested for signs of infection
brain scan--either a CT or MRI scan
How is it treated?
The main treatment is antiviral medicine given by IV (by vein) at the hospital. Because this infection can be life-threatening, the medicine may be started right away, before test results are known. Other treatments depend on your symptoms and your physical condition. For example, if you have brain swelling, medicines can be given to treat it. Or if you stop breathing, you can be put on a respirator. These life-support treatments are used until the medicine gets the virus under control and your condition starts to get better.
How long will the effects last?
It can take a long time to recover from herpes encephalitis. This is especially true if the infection has caused problems such as speech problems, weakness on one side, or balance problems. If the infection was in one particular part of the brain, the symptoms and after-effects will be similar to the effects of a stroke. These effects usually require physical therapy. Because the brain controls thinking and moving, there may be temporary or permanent loss of these abilities.
Herpes encephalitis can be fatal. If a newborn is infected and survives the infection, the baby is likely to have damage to the brain or other parts of the nervous system.
