Febrile infection-related syndrome

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at September 28, 2016
StartDiseasesFebrile infection-related syndrome

Febrile infection-related epilepsy syndrome (FIRES) is a rare brain disorder that can happen in children usually following a low grade fever. This rare syndrome is often fatal and there is no known cure. Most survivors will be left with severe physical disabilities and intellectual disabilities that may result in them requiring constant care for the rest of their lives.


Definition & Facts

Febrile infection-related epilepsy syndrome is a rare but serious brain disorder that can occur in children of any age, but it usually affects school aged children that are between the ages of five and 12. It is a little more common in boys than it is in girls.

Seizures usually begin between one day and two weeks after a mild fever or illness. The onset of the seizures is sudden. They quickly become more frequent, and the patient's condition can worsen rapidly. Little is known about what causes this syndrome and much more research is still needed.

Electroencephalography (EEG) often shows seizure activity occurring on both sides of the brain. Febrile infection-related epilepsy syndrome can lead to mental disorders and difficulties with motor skills. Of those who survive, two-thirds will suffer from mild to severe cognitive impairments. Most will be diagnosed with severe chronic epilepsy.

Symptoms & Complaints

Febrile infection-related epilepsy syndrome almost always begins with a mild fever. The most common illnesses are minor respiratory tract infections or the flu. The onset of this syndrome can begin anywhere from one day to two weeks after a mild fever.

At its most severe stage, children may suffer from hundreds of seizures. These can include simple motor seizures such as facial twitching. Complex partial seizures are recognized by a vacant stare. They can also include grand mal seizures. This stage can last anywhere from a few days to many months. The sudden onset of seizures may result in memory loss and a decline in intellectual ability.

Survivors often do not meet developmental milestones and may also suffer from regression or a loss of developmental functions. There will be a noted loss of consciousness or a high rate of confusion. This is often evident even between seizures.

These children may lose their ability to self-regulate their own body temperatures. These children are often diagnosed with refractory epilepsy. This form of epilepsy leaves the patient suffering from difficult (often impossible) to control seizure activity. Many febrile infection-related epilepsy syndrome patients also suffer from migraines and muscle pain throughout the course of their lives. 


It is unknown what causes febrile infection-related epilepsy syndrome. It is suspected to be related to an infection. It may also be caused by genetic factors or an autoimmune disease. Some medical professionals believe it may simply be a metabolic problem.

While the cerebrospinal fluid collected from a spinal tap (lumbar puncture) often shows evidence of mild inflammatory changes, there is no evidence for an infection or any known autoimmune disorder. More research is needed to identify the exact cause.

Diagnosis & Tests

Because the cause is unknown, there are no specific tests that can be used to diagnose this disorder. It is diagnosed by the process of eliminating all known causes of refractory status epilepticus. This is the term used to describe life-threatening seizure conditions that do not respond to any common anticonvulsant medications.

A full work-up should be performed to identify any treatable causes first. Spinal taps and blood tests are generally performed to rule out infectious diseases. These tests can also rule out any other known inflammatory or autoimmune conditions.

Magnetic resonance imaging (MRI) scans are used to rule out conditions that will appear in the imaging, because febrile infection-related epilepsy syndrome does not show any brain abnormalities in MRI imaging. Electroencephalography (EEG) monitoring is usually necessary to detect and document seizure activity.

Treatment & Therapy

As more research is needed into the cause of febrile infection-related epilepsy syndrome, there is no specific treatment. Initially, the seizures are treated using benzodiazepines. Benzodiazepines are then closely followed by anticonvulsant medications. The preferred delivery method for these medications is through intravenous administration. The seizures from this syndrome usually do not respond to high doses of anti-seizure medications.

Following this initial treatment, doctors may follow one of two courses of action. They may try additional anti-seizure medications. Prolonged use of these medications is not recommended in children because of the risk of potentially lethal consequences.

Due to the fact that the seizures can be very difficult to control, medical personnel may choose to place the child into a medically induced coma until the seizure activity has become more manageable. They will be hooked to an EEG to monitor seizure activity. When they have been woken up from the coma and the confusion subsides, children are often transferred out of the intensive care unit and remaining seizures are treated using anti-seizure medications.

There have been some promising developments in treatment of febrile infection-related epilepsy syndrome. Some medical professionals have found that immune treatment using corticosteroids, intravenous immunoglobulin, and plasma exchanges may be helpful.

Many children have shown impressive results when given the ketogenic diet. This is a high fat, low carb diet with plenty of protein that is often used to treat children who suffer from refractory status epilepticus. Formal research and testing will need to be done to test the validity of these treatments.

Prevention & Prophylaxis

With no known cause, there have been no studies done on the prevention of febrile infection-related epilepsy syndrome. The best thing parents can do to prevent this syndrome is to help their children maintain a healthy diet and get plenty of sleep and regular exercise in order to avoid illness in general.

Keeping immunizations up to date can reduce the risk of some infectious diseases. If there are any concerns, parents should always seek out advice and treatment from their family physician or go to the nearest emergency room.