A Unique Child: Health - A doctor's diary ... Febrile Convulsions

Febrile convulsions, sometimes referred to as febrile seizures, are frightening for parents to witness. For most children, however, a seizure of this type is usually benign, with no long-lasting effects, and it does not suggest a diagnosis of epilepsy.

The definition of a febrile convulsion varies depending what you read, but the principles are essentially the same. It is a seizure or 'fit' that occurs in the presence of a fever, suggesting infection, but in the absence of diseases of the brain such as meningitis, brain abscesses or head injury. Other causes of seizures include epilepsy, low blood sugar, calcium abnormalities and oxygen deprivation.

The majority of febrile convulsions occur between three months and five years of age. Around 2 to 5 per cent of children are affected in European countries and the United States. The incidence is higher in India and Japan and lower in China.

RISK OR SUSCEPTIBILITY

Risk or susceptibility factors for febrile convulsions include a previous episode, given that 30 per cent of children who have experienced a febrile convulsion are likely to have another one. In addition, a family history of febrile convulsions, developmental abnormalities, illness requiring hospital admission for the first month of life and maternal smoking or alcohol use during pregnancy all increase the risk.

A number of infections are particularly implicated in febrile convulsions. These include middle ear infections known as otitis media, pneumonia, urinary tract, and gut and viral infections such as influenza and roseola. Any infection causing a fever, however, may cause an event. While some texts have suggested it is the rapid rise in temperature that is responsible for the seizure, the medical evidence doesn't seem to support this.

In any case of febrile convulsion and indeed fever per se, it is important that the source of the infection is identified, so that a sinister infection such as meningitis or a urinary tract infection is not left untreated. While most cases of meningitis do not present with fever and seizures, it is a possibility.

SYMPTOMS

'Simple' febrile convulsions last for less than 15 minutes and occur no more than once over a 24-hour period. The seizure may be described in medical terms as 'tonic-clonic' and affects both the left and the right sides of the body equally. In this scenario, the body will initially become rigid or 'tonic', followed by rhythmic jerking movements known as the 'clonic' phase. As the seizure affects the whole brain, the child will lose consciousness and often be incontinent. Tongue biting may also occur during the clonic phase.

'Complex' febrile convulsions last longer than 15 minutes, may recur over a 24-hour period and can affect one side of the body more than another.

It is particularly important that sinister infections such as meningitis and other causes of seizure are excluded if a child has a complex convulsion. Irrespective of the type of febrile convulsion, for a short while after the seizure the child will be drowsy and confused, described by doctors as the 'post-ictal' phase.

TREATMENT

Children having a fit should be put into the recovery position to ensure any vomit doesn't obstruct their airway. Immediate medical help should always be sought. The paramedics or doctors may be required to give oxygen and drugs to suppress the seizure, although for most children, the seizure will have stopped by the time medical help arrives.

Doctors will look for a source of infection, but if the source can not be found, the infection is serious or if the febrile convulsion is complex, the child will probably be admitted to hospital for further tests and treatment. Occasionally children will require a CT scan of their brain or a lumbar puncture.

Medication such as paracetamol and ibuprofen may be recommended to help with the symptoms of infection, although there is little evidence that these drugs reduce the chances of having a febrile convulsion. Aspirin should not be given to children below the age of 16. Bacterial infections may be treated with antibiotics.

LONG-TERM EFFECTS

In the vast majority of children who experience febrile convulsions, there are no long-term complications. The risk of epilepsy is slightly increased, from 1 per cent background risk to between 1.5 and 2 per cent in patients who have had a febrile convulsion. This risk is further increased after a complex rather than simple convulsion, in children with a family history of epilepsy and in those with other medical conditions such as neurological diseases.

Dr Raj Thakkar BSc(Hons) MBBS MRCGP MRCP(UK) is a full-time GP in Buckinghamshire