Symptoms | Febrile convulsion

Symptoms

A sick child with a fever has a febrile spasm when he or she suddenly becomes dizzy or unconscious and twitches or stiffens all over the body. This can be caused by the child’s eyes being rolled (deviation of gaze), turning blue (cyanosis) or emptying the bladder or intestinal contents. In some children, febrile convulsions do not manifest themselves with stiffening of the body, but with sudden flaccidity.

The symptoms can be very different, but usually disappear by themselves after a maximum of 10 minutes. After a febrile spasm, the child is usually sleepy and exhausted. Many parents are afraid that their child will have a febrile spasm at night while sleeping, which then goes undetected.

However, this is rather unlikely, as experience shows that the seizure occurs in the afternoon or evening. If the symptoms persist for more than 15 minutes, recur within 24 hours or only affect one part or half of the body, the child must be taken to a clinic immediately, as this could be a complex febrile spasm and if the spasms persist, there is a risk of damage, e.g. paralysis (paresis). A febrile spasm is the result of a rapid and sudden rise in body temperature.

In small children, the network of nerve cells in the brain is not yet fully developed, so that increased electrical discharges can very easily occur.As the temperature rises, the nerve cells in the brain become particularly sensitive to unplanned, spontaneous discharges, which quickly reach and exceed the cramp threshold. Then the children’s muscles all over the body start to twitch and they become unconscious. To trigger the febrile spasm, however, it is not crucial that the body temperature exceeds a certain degree, but the speed with which the temperature rises.

A body temperature of 38°C or higher is called a fever. Elevated temperatures are already present at 37.5°C. If an infant has a very low body temperature and then the temperature rises rapidly, it is sometimes possible for a convulsive event to occur at a temperature of 37.5°C without a fever by definition.

It is often the case that the child only notices that it has a fever when it is already cramping. For this reason, care should also be taken, for example, with hypothermic infants to ensure that the warming does not occur too quickly. Events similar to febrile convulsions, but without a rapid increase in body temperature, are usually a sign of epilepsy or other neurological diseases.

If a child has had a febrile convulsion, a doctor should always be consulted, as he or she must investigate what caused the seizure. In the case of a real febrile convulsion, the child has an illness with fever that does not affect the nervous system (e.g. airway infection, middle ear infection, three-day fever). If this is not the case, there are many different things that can trigger a seizure in a child.

The paediatrician must rule out the possibility that there is no inflammation of the meninges (meningitis) or brain (encephalitis). To do this, it may be necessary to withdraw cerebrospinal fluid (liquor) from the nerve canal of the spinal column with a needle (liquor puncture). It may also be necessary to record brain waves (EEG), examine the back wall of the eye (ocular fundus examination), examine the blood or take a picture of the brain using an MRI of the brain (MRI) in order to clarify suspicions of inflammation of the nervous system, epilepsy, an increase in pressure in the brain or hypoglycaemia.

Therefore a hospital stay may be necessary, especially if a complicated febrile spasm is present. The paediatrician must rule out the possibility of inflammation of the meninges (meningitis) or the brain (encephalitis). For this purpose, it may be necessary to withdraw cerebrospinal fluid (liquor) from the nerve canal of the spinal column with a needle (liquor puncture). It may also be necessary to record brain waves (EEG), examine the back wall of the eye (ocular fundus examination), examine the blood or take a picture of the brain using an MRI of the brain (MRI) in order to clarify suspicions of inflammation of the nervous system, epilepsy, an increase in pressure in the brain or hypoglycaemia. Therefore a hospital stay may be necessary, especially if a complicated febrile spasm is present.