Febrile seizures

What is it?

Febrile seizures occur in children. They are caused by a high fever or by a sudden rise in body temperature.

The brain's nerve cells (neurons) communicate with each other by giving off tiny electric signals. When someone has a seizure (convulsion), the way the brain's nerve cells give off signals suddenly changes, which can trigger different muscles in the body to twitch or jerk uncontrollably.

Febrile seizures usually happen at the beginning of an illness, soon after the fever first starts. Febrile seizures can affect up to 5% of children. They are most common between ages 6 months and 5 years.

A child is more likely to have a febrile seizure when other family members have had febrile seizures. Children who have delays in normal development are also more likely to have seizures with fever.

More than one in three children who have had a febrile seizure will have another one within one year. The risk of having another seizure is greater in children who had their first seizure when they were younger than 12 months old.

Most children eventually grow out of this condition.

Symptoms

Signs of a febrile seizure may include

• jerky, twitching movements of the arms and legs
• stiffness
• rolling eyes
• passing out (loss of consciousness)
• not responding to voices or touch.

Diagnosis

In most cases, a doctor can diagnose febrile seizures based on a description of the episode. However, the doctor may want to see your child to look for the cause of the fever. In particular, the doctor will want to make sure your child does not have any signs of a serious infection of the brain (encephalitis) or of the coverings of the brain and spinal cord (meningitis).

Expected duration

Febrile seizures usually last less than five minutes. If they last longer than this, call your doctor right away.

Prevention

There is no way to prevent the first febrile seizure. In children who already have had one febrile seizure, parents should be taught how to best manage a fever and a seizure if it occurs. Preventing high temperatures will decrease the risk of febrile seizures. Also parents should be reassured that febrile seizures are rarely harmful if they last only a few minutes.

Parents should never give children aspirin or a salicylate-containing product to reduce fever. Although rare, aspirin use is linked to Reye syndrome.

Some medications may help to prevent more seizures. However, the potential side effects of these drugs may be worse than the benefits. Therefore, they are rarely prescribed.

Treatment

You cannot stop a seizure once it starts, but you can do the following to protect your child:

• Try to stay calm.
• Place the child on his or her side on a safe, flat surface, such as the floor. Keep the child away from furniture or objects that may cause injury.
• Do not restrain your child or put anything between his or her teeth.
• Observe your child carefully so you can describe the events to your doctor.
• Keep track of the time. If the seizure lasts longer than five minutes, call 911.

After a seizure, call your doctor for advice.

Treatment involves reducing the fever and treating whatever is causing the fever. Hospitalization usually is not necessary, unless the condition causing the fever requires it.

Prognosis

The outlook is excellent. Febrile seizures generally are not harmful and do not cause long-term problems. Children with cerebral palsy, developmental delays, or certain neurological problems are slightly more likely than other children to develop epilepsy (repeated seizures that are not related to fevers) after febrile seizures. Children who have repeated febrile seizures are at an increased risk of developing epilepsy. However, the risk is still very low.

Additional info

American Academy of Pediatrics (AAP)
https://www.aap.org/

National Institute of Neurological Disorders and Stroke
https://www.ninds.nih.gov/