Febrile Seizures
Having a febrile seizure is a frightening experience for both the child and the family. Some parents admitted that they felt like their child was going to die. However, almost all children who suffer a febrile seizure recover quickly without complications. If your child had a febrile seizure you would be very restless and surely would have a lot of questions and queries in your mind. However, once you understand more about this condition you will realize that there is nothing much to worry about if you know how to face the situation well.
So, if you are a parent looking for more information about febrile seizures, this article is for you. Here, you will get the answer to all your questions and we will try to explore more about febrile seizures in a more simple and comprehensive manner.
What is a febrile seizure?
Febrile seizures are seizures in little children, usually aged between 6 months to 5 years in the presence of fever and without any evidence of brain infection. Febrile seizures occur in about 2 to 5% of the population, whereas epilepsy occurs in only 1 to 2% of the population which confirms that febrile seizure is rather a commoner condition in the population.
The majority of febrile seizures (about 90%) will occur before the age of 3 years, maximum between 12 and 18 months, and disappear later on.
What causes febrile seizures?
The exact cause of febrile seizures is unknown. Febrile seizures can occur with any disease, causing fever. It is believed that a combination of viral infections and genetic susceptibility plays a role in the causation. The common viral etiologies are HHV-6 and other viruses like Influenza virus. Although uncommon, vaccines like MMR, MMRV and DTaP which usually cause fever can also induce febrile seizures.
If your child has immediate family members with febrile seizures, they are more prone to get febrile seizures.
How do febrile seizures happen?
How febrile seizures occur is not clearly understood. When the body fights against the infection it creates cytokines (IL-1, IL-6, TNFa). They are chemical molecules that help activate and coordinate the immune response. These cytokines can enter the brain and activate the NMDA receptors which cause excitation of the brain leading to seizures. It is very important to understand, not the temperature itself, but the immune response that is triggered by the viral illness is important in the occurrence of febrile seizures.
These cytokines also induce the brain area called the hypothalamus which controls the temperature to induce fever as a part of the immune response. The fever makes the brain cells more excitable which makes the neurons more responsive to cytokines thereby facilitating seizures.
In addition to that, fever leads to hyperventilation which decreases the acidity of the brain leading to more seizures. (This is the opposite of the action of the ketogenic diet on epilepsy which reduces the occurrence of seizures by increasing the acidity of the brain environment.)
What are the types of febrile seizures?
Febrile seizures fall under two major categories based on how the seizure looks like and the duration of the seizure. It is important to identify what type of seizures your child is having, for better management of the seizures.
First is simple febrile seizures.
- These seizures are generalized tonic-clonic seizures, which cause shaking of the whole body with arms and legs,
- This type of seizure lasts for less than 15 minutes (mostly, less than 5 minutes).
- They are not recurrent, which means there will be no more than one seizure within 24 hours.
Simple febrile seizures are comparatively safer with no or minimum long-term harm for the child.
The second is Complex febrile seizures:
- It is a focal seizure that involves a specific region of the brain causing convulsions in one or several parts of the body.
- It lasts longer than 15 minutes.
- There will be more than one seizure within 24 hours.
Usually, the child will be confused and drowsy for 5 to 10 minutes after the seizure, but not longer. If the child stays confused longer than that, further evaluation is required for diagnosis.
Can febrile seizures cause brain damage?
Short-lasting simple febrile seizures do not cause brain damage. However, long-lasting febrile seizures, especially if they last longer than 30 minutes (Febrile Status Epilepticus) can cause brain damage and may manifest as epilepsy later in life.
How to evaluate for febrile seizure?
Medical history is very important in the evaluation of a child with febrile seizures. History of a recent infection or vaccines, history of previous febrile seizures and family history of febrile seizures is important in arriving at a diagnosis. The presence of headache, light sensitivity and neck stiffness direct the diagnosis towards meningitis that may be causing seizures and the fever. It is very important to differentiate febrile seizures from meningitis as it is a life-threatening condition and prompt management is indicated. Also, complex febrile seizures should be differentiated from simple febrile seizures as the first one is more dangerous.
Your doctor might need to do further testing based on the evaluation, especially in complex febrile seizures. In simple febrile seizures, we do not need to work up much as it is mostly self-limiting.
Lab testing is important to identify the source of infection. Eg: respiratory viruses, and bacteria. Urine analysis and culture for suspected urinary tract infections and throat swabs for respiratory tract infections will be done. Blood cultures will also be taken in certain cases. Blood tests like serum electrolytes, sodium, and glucose will also be done. Imaging studies like chest X-rays or abdominal US are indicated in certain suspected infections. Lumbar puncture or spinal tap is reserved for suspected meningitis cases.
Brain imaging with a CT scan or MRI of the brain is not routinely done and is done only in complex febrile seizures when a brain lesion or infection is suspected. EEG, which looks at the electrical activity of the brain is done in cases of complex febrile seizures or in cases where seizures continue without fever creating doubt about epilepsy. EEG is not indicated in simple febrile seizures.
Case:
20 months old baby Charlie had generalized tonic-clonic seizures (whole body seizures) lasting for 2 minutes with a fever of 38.5 C or 101.5 F and a runny nose due to a viral illness. His examination was normal. He was given antipyretics and the temperature dropped. The seizure didn’t recur and there were no other complaints. This was diagnosed as a simple febrile seizure which didn’t require further intervention.
Can febrile seizures recur?
Yes, about one-third of children with febrile seizures will have a recurrence. If febrile seizures occur before the age of 1 year, the chance of recurrence is 50%. Having a first-degree family history of febrile seizures, seizures that happened before the fever or illness, or seizures that happened with low-grade fever are other risk factors for recurrent seizures.
The majority will come only one more time, with a few being limited to three or four times. Febrile seizures very rarely occur more times than that unless there is an underlying cause like epilepsy or another genetic cause.
It is important to understand that epilepsy occurs in the absence of a fever whereas febrile seizures occur only with a febrile illness. However, in epilepsy, a febrile illness like a simple viral infection can trigger a seizure.
How to help your child if they have a febrile seizure?
If the child starts having a seizure, make sure to time the event, keep them safe from hitting any hard object or falling, and turn them on their side to prevent aspiration of any oral secretions and help them breathe. Make sure you don’t feed them anything during the event and the postictal period (immediately after the event). You can start rescue treatment if the seizure continues for more than five minutes as explained below.
How do you treat febrile seizures?
Simple febrile seizures stop on their own in less than 5 minutes and don’t require any particular treatment.
What should be treated is the underlying cause of fever such as an infection so that the fever subsides and the child is safe from febrile seizures.
If seizures last longer than five minutes or if the child has got complex febrile seizures, anti-seizure medications like Lorazepam or Ativan, Midazolam and Diazepam are indicated. In addition to intravenous and intramuscular injections, there are other forms of the drugs like rectal diazepam (Diastat), nasal midazolam (Nayzilam) or nasal Diazepam (Voltoco).
Controlling the fever is a must in the management of febrile seizures. Most of the causes are viruses that are self-limiting and all you need to do is control the fever using Acetaminophen or Ibuprofen. A combination of these drugs will be used. It’s important to avoid Aspirin in children because it can cause Reye’s syndrome, liver toxicity and brain swelling.
Can febrile seizures increase the risk for epilepsy?
The general risk of epilepsy in the population is 1- 2%, and with febrile seizures, it goes up to 2 to 5%. Therefore, febrile seizures increase the risk of epilepsy slightly.
The risk further increases with complex febrile seizures, developmental delay, or having a first-degree relative with epilepsy.
How to prevent febrile seizures?
In febrile seizures, the primary target is to prevent any complications from the seizure itself or indirect injuries during the event. No specific measures are taken in order to prevent febrile seizures.
Generally, as in any febrile illness, fever should be well-controlled once it occurs and supportive therapy should be given to help the ongoing febrile illness. Long-term antiseizure medications are not effective in preventing febrile seizures.
What to know about vaccinating children with Febrile seizures?
It is recommended by the CDC and many other pediatric organizations to give routine childhood vaccines to patients with febrile seizures. DTaP is preferred over whole Pertussis. There is a little higher risk for febrile seizures with DTaP and MMR vaccines, however, avoiding these vaccines carries much higher risks to the child by contracting these dangerous infections. Also, vaccines provide coverage over febrile seizures that can be triggered by dangerous infections like measles, chickenpox, and influenza. Therefore it is recommended that routine vaccines are administered for children who’ve had febrile seizures.
Take Home
Febrile seizures, when identified correctly and managed well, is rather benign, less dangerous condition which you can easily survive without any complications. In little children, it is important to recognize this type of seizure which goes unrecognized by parents and even doctors leading to disastrous complications for the baby. Parents should be well-educated on the condition so that there won’t be unwanted fears and concerns about the condition and as well they can take necessary measures during and after the event to prevent complications. In seizures lasting for more than five minutes (when a complex febrile seizure is suspected), hospitalization is important where the condition will be well managed with immediate action to stop seizures.