Febrile seizures

A type of convulsion, which occurs in babies, toddlers and young children, febrile seizures can be extremely alarming to witness but typically resolve without any complications.

Arising in tandem with a spike in temperature, in most cases febrile seizures have a benign cause, which is easily treated. Nevertheless, although febrile seizures are a common incidence, understanding how to administer treatment is important because further injuries can be easily sustained without proper preventative measures.

What are febrile seizures?

Although they may look similar, febrile seizures are not a form of epilepsy. The latter typically manifests as recurrent convulsions, which are triggered by abnormalities within the electrical signals in the brain. By contrast, febrile seizures are caused by a sharp and usually sudden rise in the body’s core temperature.

Febrile seizures affect infants from the age of three months to around six years of age although are most commonly seen in toddlers aged 12-18 months. They present as convulsions, which appear while the child is feverish, usually when the body temperature is 38 º C or above (100.4 º F).

Each convulsion doesn’t usually last longer than a few minutes, and they can be one of the first signs that a child or infant is unwell.

Febrile seizures do not indicate that there is an underlying disease or illness but it is essential for the child to be seen by a doctor to ensure that febrile seizures are not mistaken for a more serious condition.

Presenting features

Febrile seizures can vary in their presentation from severe symptoms which, affect the entire body, such as shaking, contracting or trembling of the muscles to a much milder presentation which may simply involve staring.

During each seizure the child may lose consciousness and may appear to be jerking and twitching both their arms and their legs.  These symptoms usually accompany a temperature of at least 38 º
C (100.4 º F).

Each febrile seizure can be grouped into one of two categories:

Simple

The more frequent type of febrile seizures, these are extremely short-lived lasting anything from just a few seconds up to around 15 minutes. These type of seizures do not occur more than once within any 24 hour period and tend to generalised rather than confined to a specific body part.

Complex

These type of febrile seizures are less common but tend to occur far more frequently within any given 24 hour period, are longer than 15 minutes and can be limited to one side of the body.

Both types of seizure may include eye rolling, moaning, involuntary urination, unconsciousness, vomiting, twitching, shaking or other movements.

After the convulsion has ceased, the child may feel very drowsy and tired, but for some, there are no sequelae, temporary or otherwise.

Red flags

Although every infant or child who has febrile seizures should be checked over by a doctor, there are some signs which mean that medical attention should be sought immediately.

If the child exhibits any of the following an ambulance should be called or the child immediately taken to A&E:

1. a stiff neck
2. vomiting
3. extreme drowsiness or lethargy
4. breathing difficulties
5. a seizure which lasts longer than 5 minutes
6. a change in the colour of their skin
7. failure to respond normally to stimuli
8. more than one seizure within 24 hours
9. a seizure which is confined to specific body parts

If a child or infant has not yet completed their immunisation programme they could be at a greater risk of developing meningitis if they suffer a febrile seizure. It’s therefore essential to monitor the child for any indications that meningitis may be developing such as excessive vomiting, a bulging fontanelle (in infants) or a stiff neck.

Causes and triggers

In many cases febrile seizures are caused by a viral infection, which leads to a raised temperature. Roseola and influenza are two of the most common culprits. The theory is that the convulsions occur because of the way the immature brain of a baby or child deals with the high fever. However, scientists are not yet entirely certain why febrile seizures occur in some infants and children and not others.

Bacterial infections are not thought to be a causative factor.

There is some evidence to suggest that family history may play a part in predisposing an individual to have seizures associated with a fever, and more specifically in suffering febrile seizures.

Around a third of children who have had one febrile seizure will go on to suffer another one, typically between 12-24 months of their first one. Infants aged under 15 months who suffer a febrile seizure are at an increased risk of suffering further convulsions in the future.

Most febrile seizures completely resolve by the age of 5 and there is only a very slightly enhanced risk of going on to develop epilepsy in the future. Very few febrile seizures occur younger than six months or after the age of three years.

Some types of febrile seizures can develop post-immunisation. It’s important to recognise that this is not due to a reaction to the vaccination directly, but instead a complication of the slight rise in temperature, which a vaccination can sometimes cause.

Tetanus, diphtheria and MMR are the vaccinations most likely to lead to a fever, and consequently febrile seizures.

Treating febrile seizures

As described above, febrile seizures don’t normally carry any risk, although they can be frightening to observe, particularly for parents. Therefore, treatment is typically confined to eliminating the risk of complications or injuries caused by the convulsion, and trying to prevent a recurrence wherever possible.

During a seizure

Trauma can present one of the greatest threats during a seizure so it’s essential that the child is laid down on a surface which is safe and where they cannot inflict further injury to themselves, such as the floor. An elevated position is less than ideal because of the risk of rolling onto the floor. Ensure there are no sharp objects or hard surfaces nearby (such as table corners).

The child should be placed onto their side to help reduce the risk of choking. This is particularly helpful if they excessively salivating. Loosen tight clothing.

Do not try and restrain or hold the child in one position (providing they are in a safe place) as it could cause further trauma or injury. Do not give them any medicine, food or drink or place anything at all in their mouth. The child should not be placed into water to try and cool off.

Take note of how long the seizure lasts and exactly how it is presenting as the doctor will need to know (see below).

Observe carefully for any of the warning signs (described above) and if detected, call the emergency services immediately. In all other cases, call the doctor once the seizure is over to get your child checked over. Remaining calm throughout is crucial.

Following the seizure

Febrile seizures often do not require any treatment but it’s vital for your doctor to establish the type of seizure that occurred (other types of convulsions are not as benign in nature so need to be ruled out). If you child is aged below one year and has been suffering additional symptoms such as vomiting or diarrhoea, some further tests may be required.

If treatment is prescribed, it will typically be medication such as ibuprofen or acetaminophen to try and bring down the fever. However there is no guarantee these will prevent any further febrile seizures from occurring.

Children older than age 3 can be given aspirin but it should be used with extreme caution, and never administered to a child or teenager recovering from chickenpox or symptoms associated with flu. This is because research has shown that it can be linked to the potentially life-threatening condition known as Reye’s Syndrome.

If the seizures are longer than five minutes, the doctor may decide to prescribe some anti-convulsant medication but this is not indicated in every case. These types of medication often have significant side effects so will only be prescribed when absolutely necessary. Some of the types of drugs, which may be prescribed, include Diastat (diazepam administered via the rectum), clonazepam or oral diazepam.

In very rare cases where the source of the infection cannot be identified, the infection is serious, or if the seizure was particularly long, the doctors may suggest that your child remains in hospital for observation. This is the exception rather than the norm, particularly for simple febrile seizures.

Diagnosis

Before deciding whether treatment is necessary, the doctor will need to establish firstly that it was indeed a febrile seizure and then the nature of the underlying cause.

Appointment checklist for parents/guardians

When you take your child to see the doctor after the seizure, they will have lots of questions for you. Wherever possible, have the following information ready:

1. did your child have any pre-morbid illnesses or symptoms?
2. how did the seizure present?
3. how long did the seizure last?
4. has this happened before?
5. is there a family history of febrile seizures or any other types of convulsions or seizures?
6. has your child had contact with any other person with a contagious illness or disease?
7. is there any history of neurological disease or head trauma in your child?

To help answer these questions clearly, it is a good idea to write down a description of the child’s seizure as soon as you are able to, including the signs and symptoms you observed both before and during. Also make a note of any medication or treatments they are taking, including any alternative health or vitamin supplements.

Don’t forget to ask the doctor any questions you have about the nature of febrile seizures including the likelihood of recurrence and what you should do if it recurs.

Reaching a diagnosis

Once the doctor has taken a clear history of the type of seizure, which occurred, they may then want to carry out some further tests to decisively reach a diagnosis.

For cases where a simple seizure has occurred, a blood and urine test along with a lumbar puncture could be requested. This checks for any major underlying infection of the central nervous system, such as meningitis.

Where a complex seizure has taken place, the doctor may also request an EEG in order to take a closer look at brain activity. For seizures, which only presented on one side, an MRI scan may be required to check the brain for any other underlying causes.

These relatively simple investigations are usually sufficient to identify whether a febrile seizure occurred, and from there the appropriate treatment, or course of action can be agreed.