Encephalitis

Reye's syndrome is a special form of encephalitis coupled with liver dysfunction seen in young children and those in their early teens.

Invariably, the individual who develops Reye's syndrome has had an earlier viral infection from which they seemingly have recovered. Hours or days later they will begin to develop symptoms such as vomiting, convulsions, delirium, and coma. A virus such as the influenza virus, varicella (measles), and coxsackie virus are responsible. For reasons unknown, giving a child aspirin tablets to reduce fever accompanying a cold or flu can trigger Reye's syndrome.

At the time the nervous system begins to show signs of infection, the liver is also being affected. Fatty deposits begin to replace functional liver tissue. Similar fatty tissue can be found in the heart muscle and the kidneys. The relationship between the viral effects on the brain and the parallel liver damage is not known.

Treatment is not specific to the virus, but is directed at relieving pressure on the brain and reducing symptoms. The head of the bed can be elevated and the room left very cool. Care is taken to maintain blood sugar level at normal and not let it drop. Other blood factors such as sodium and potassium also fall quickly and must be corrected.

The mortality rate for Reye's syndrome can be as high as 25-50%. Early diagnosis and initiation of treatment play an important part in keeping the mortality low. Other factors, including age and severity of symptoms, affect the outcome. Some children who survive Reye's syndrome will show signs of brain damage such as impaired mental capacity or seizures.

Thus, it is important that children who contract one of the common childhood diseases of viral origin, such as mumps, measles, or chickenpox be watched closely to insure they do not develop symptoms of a brain infection from the same virus.