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Recognising that a baby is having a seizure may be quite difficult even for experienced doctors. Seizures in babies are very different compared to seizures that occur as part of
in older children and adults.
The most common sign that a seizure is happening is a run of repeated “jerky” or “twitching” movements of the arms or legs that continue when we gently hold one of the limbs to see if the movements stop. This can be seen on the video here
Other babies have changes in their behaviour – such as repeated hiccoughs, jerky movements of the eye or lip-smacking/chewing movements – although all these we see in babies that are not having seizures. Some examples of this can be seen on the video here
Because seizures can be very difficult to identify or diagnose it is really important to check whether the movements occur with changes in the function of the neurons in the brain – we do this by making a recording of the brain waves – called an electroencephalogram or EEG
Epilepsy refers to more than one seizure, usually a run of seizures, occurring usually in an older child or adult. We do not refer to seizures occurring in newborn baby (neonatal seizures) as Epilepsy. Less than 1-in-5 babies who have neonatal seizures go on to have seizures of some type later in life, but many fewer go on to develop Epilepsy
Epilepsy consists of a group of conditions, taken together these are termed the Epilepsies, which differ widely in the age of onset, types of seizures, response to treatment, and underlying and concomitant disorders.
Most neonatal seizures either settle spontaneously or respond well to treatment. To a large extent this depends on the reason the seizures are happening (see “why do babies have seizures”)
TESTS THAT WE DO TO DETECT SEIZURES
When a baby presents with a seizure, doctors will perform a thorough examination, focused on finding the underlying condition. The doctor will be looking for the level of consciousness, muscle tone, body-posture and reflexes as well as differences between movements on each side of the body. We also examine the skin carefully for birthmarks, changes in colour, rashes, bruises or bleeding, all of which are sometimes signs of the cause of seizures. All other body systems will also be checked.
The doctor will then
perform some blood tests to work out if an immediate treatment needed.
Imbalance in salts and chemicals in the body and infections will be ruled
out first. Often the doctor will want to rule out an infection of the brain
if suspected (meningitis is the infection of the tissue layers surrounding
the brain, encephalitis is an infection of the brain itself) by doing a
lumbar puncture - a test where your doctors will drain a little amount of
cerebrospinal fluid - the fluid surrounding the brain and the spinal cord –
with a small needle from the lower part of your baby’s back. In most cases
antibiotics will be started, as it takes a few days to be sure there is no
Next the doctor will perform an electroencephalogram (EEG) - this is used to record the brain activity by picking up the very low intensity electrical signals from the brain cells with the help of electrodes which stick to the scalp with the help of some gel. We only record the brain signals and do not transmit anything to it.
As clinical features of neonatal seizures are variable and in many cases we cannot be sure that a baby has seizures, continuous monitoring of the electrical activity of the brain with EEG is necessary. At the same time we make a video recording of your baby; to detect very minimal changes with in behaviour that occur with seizures recorded on the EEG.
We also monitor heart rate and oxygen levels in your baby, as often a drop of oxygen saturation and an increase in heart rate can be seen with a seizure.
Above you can see a baby with applied EEG monitoring using an EEG cap.
A normal EEG trace in an awake newborn. You can see the mixture of different frequencies. The activity of right side of the brain is represented by red lines (channels) and the left side is represented by blue lines. The heart rate is registered at the same time and demonstrated in the last trace (in violet).
The interpretation of a multichannel EEG requires special expertise and not all neonatal intensive care units (NICUs) have this available 24 hours a day, so we use a special display that makes it easier to detect seizures called the amplitude integrated EEG (aEEG). This can be done with all the EEG electrodes in place, or sometimes only four or five are needed. The aEEG is relatively easy to interpret.
You can see the reduced set of electrodes on the head of the baby, attached with little white stickers. The sticker next to the nose is attaching the nasogastric tube to feed the baby and this is not part of the aEEG system.
The traces above give the multichannel EEG where you can see the rhythmic activity of a seizure (first two red channels). Below this the time-compressed, amplitude integrated EEG is projected, the time cursor in red indicates the position of the chosen time segment. In the upper aEEG trace you can see a change of the lower band limit with the seizure.
Neonatal intensive care unit:
Above you can see a baby ventilated on the intensive care unit with applied EEG monitoring.
The picture above gives an overview of a neonatal intensive care unit.
It is helpful to have a test which shows us
something about the brain structure by taking a picture. We use
technologies that are not harmful to the baby or brain, magnetic fields or
ultrasound avoid the use of radiation and are the safest, though sometimes
x-rays are needed in a scan called a CT (or computerised tomogram).
Cranial ultrasound is readily available in a modern neonatal intensive care unit and many of the doctors are skilled in its use. As your baby’s skull has not fully joined together in the first months after birth, we can use the soft spot or fontanel on top of the head to use ultrasound without bone making it very difficult to see anything. Ultrasound works like a submarine’s sonar, a sound wave is sent out (much too high pitch for us to hear) and we measure the reflection of echoes from the brain. As the tissues of the brain reflect sound differently we can easily build up a picture of the brain. We can identify bleeding in or swelling of the brain quite easily. We can also get information about how fast the blood flows in the vessels inside the brain using a special type of ultrasound called Doppler ultrasound – this gives us really useful information about any swelling or blockages in blood vessels.
Magnetic resonance imaging (MRI) gives us the most information about the brain and is usually performed in most babies with seizures. MRI uses a magnet to detect very faint signals from the brain and then the computer builds up a very accurate picture. The MRI takes between 30 minutes and an hour to complete and is best done when your baby is sleeping – e.g. after a feed or a small dose of a sedative. The MRI can identify many of the conditions that cause seizures and tell us how healthy the brain is. Different hospitals do scans in different ways and your doctor will explain this procedure to you.
TREATMENT OF NEONATAL SEIZURES
We are always concerned that seizures may harm the developing brain of your baby. Therefore treatment is recommended even if seizures are only seen on the EEG and you do not see any behaviour changes in your baby (e.g. no rhythmic movements). In general treatment is started shortly after the seizure, even more so if seizures are occurring repetitively.
If your baby does not respond to this medication there are several drugs available with names like Midazolam, Lidocaine, Phenytoin and Levetiracetam all are used as second line drugs – this means when we know that Phenobarbitone was not effective. Which drug is preferentially used is dependent on the country where you are living and the experiences of the centres with the individual drugs.
In general we give the medication via intravenous line or drip in order to have a quick response. If we need a longer treatment the preparation might be given as a solution that your baby take in a feed.
Research into which are the most effective medicines to use is really difficult to do and we are part of a group of doctors trying for the first time to work this out using the best technology available..
In a small number of babies with seizures an disorder of their vitamin system is present and some babies respond to a large dose of vitamin B6, which is usually given with an EEG test running to see if it is effective.
OUTCOME FOR THE BABY WHO HAS HAD SEIZURES
A single seizure of a short duration does not cause appreciable harm. However we know that very frequent seizures can harm the brain and make it more likely to have further seizures. To protect your baby’s brain from further damage we also treat seizures only detected on the EEG.
Often newborns require medication for a short period after birth. Ongoing seizures are very uncommon in the newborn, compared to older children or adults and often settle after a few days. When your baby is discharged from the hospital the medication might already have been stopped or reduced. For some babies seizures persist and medication needs to be continued and your baby monitored as an outpatient.
We know that in the neonatal brain numerous developmental changes occur (see section why do babies have seizures). And we also know that anti-seizure medications can have an impact on development. For example when a medication makes your baby sleepy it cannot discover the world in the same way and acquire new skills in the same speed. Because of this we always try to reduce medications (and therefore the risk of side effects) or stop them as soon as possible. It is thought that short periods of treatment do not affect long term development, but the underlying reason that the seizures occurred may also indicate problems – your doctor should discuss this with you.