DEAR DOCTOR K: My 9-month-old daughter had a seizure last time she had a high fever. The pediatrician said it could happen again. What do I need to know?
DEAR READER: The medical term for what your daughter experienced is febrile seizure. I was taught that febrile seizures are caused by a high fever or a sudden rise in body temperature. The effect of the higher body temperature makes the brain “irritable” and causes a seizure. But in the last few years, we’ve learned it may be more complicated than that.
Some childhood seizures are caused by a new infection with a common virus, called human herpesvirus-6. This virus infects most children at a young age and remains in their bodies for the rest of their lives.
When a child first is infected with this virus, it travels to the brain, where it causes a fever — and may cause chemical changes in the brain that lead to seizures. We don’t know how many febrile seizures are caused by this virus. We do know that severe febrile seizures that don’t end promptly often are caused by the virus.
What is a seizure? The brain’s nerve cells communicate with each other by giving off tiny electric signals in a tightly controlled process. However, when someone has a seizure, large numbers of cells start firing in an uncontrolled process. (On my website, AskDoctorK.com, I’ve put an illustration of what electrical activity in the brain looks like normally and during a seizure.)
Depending on where in the brain the seizure starts, and whether the electrical firestorm travels to another part of the brain, seizures have different effects on the body. Some seizures cause a person to temporarily lose consciousness. Some cause different muscles in the body to twitch or jerk uncontrollably. Others just cause temporary strange behavior.
As your doctor mentioned, many children who have had a febrile seizure will have another one. One of the best ways to prevent one is to prevent a high fever. If your daughter develops a fever, have her drink plenty of water and fruit juices to prevent dehydration. Give her ibuprofen (Advil, Motrin, others) or acetaminophen (Tylenol), but not aspirin.
You cannot stop a seizure once it starts. If your daughter has a seizure, the following can help keep her safe:
— Place her on her side or stomach on a safe, flat surface, such as the floor. Keep her away from furniture or objects that may cause injury.
— Tilt her head to the side to prevent choking.
— Do not restrain her, or put anything between her teeth.
— Observe her carefully so you can describe the events to your doctor.
— If the seizure lasts longer than about five minutes, call your doctor.
Otherwise, call your doctor after the seizure is over, to arrange an appointment if necessary.
It can be extremely distressing to watch your child experience a seizure. Fortunately, most children outgrow this condition, and febrile seizures generally are not harmful and do not cause long-term problems.
(Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.)