Seizures in babies

Short answer: seizures in babies often look different from seizures in older children. Instead of shaking all over, a baby may stare, move the eyes to one side, smack the lips or pedal the legs, often with changes in heart rate, and some seizures cause no visible signs at all.^1,2,3 Call 911 if it is your baby's first seizure or if a seizure lasts more than 5 minutes.⁴

A seizure is the physical change in behavior that happens during an episode of abnormal electrical activity in the brain.² This page explains the types and signs of seizures in babies, including during sleep, how to tell them from normal baby movements, what causes them, what to do during one and when to get emergency help. It is general information for parents, not a diagnosis. If you are worried about your baby, contact your baby's doctor.

How are seizures in newborns different from seizures in older babies?

Newborns. Seizures are the most common neurological emergency in the newborn period. Unlike seizures later in childhood, they are often provoked by an acute cause such as a brain injury, and they may be electrographic-only, meaning they show on an EEG but not to the eye.³ They occur in about 1.5 to 3 of every 1,000 live births.¹ In a US study of 426 newborns with seizures, most had many seizures and about half needed two or more medicines.⁵ A newborn with seizures should be cared for in hospital, with continuous video-EEG if possible.¹

Older babies. After the newborn period, seizures are less often provoked by an acute cause.³ The incidence of epilepsy is high in the first two years of life. Some infant epilepsies settle on their own, while others, called developmental and epileptic encephalopathies, affect development.⁶ Early recognition is a key step in the care of infantile spasms.⁷

What do seizures look like in babies?

Doctors group seizures by the main thing you can see. These are the main types of seizures in babies:^1,3

• Subtle seizures. The most common type in newborns. Signs include fluttering eyelids, a fixed stare or eyes turning to one side, smacking, chewing or other mouth movements, and pedaling leg movements, often with a racing heart.
• Clonic seizures. Rhythmic jerking, about 1 to 3 jerks a second, in one part of the body or in several parts.
• Tonic seizures. A sudden stiffening of the muscles, usually lasting less than a minute. The trunk or neck may hold an uneven posture, or an arm or leg may stay stiffly bent or straight.
• Myoclonic seizures. Quick, single jerks of the head or a limb, or of both arms and legs at once.
• Epileptic spasms. A sudden bend forward, arch backward or mix of both, involving the trunk, neck, arms and legs and lasting 1 to 2 seconds. Spasms usually come in a series, often just after waking.⁸ They can be as subtle as a head nod or eye rolling, and parents sometimes mistake them for colic or reflux.⁹
• Non-motor seizures. The ILAE lists two non-motor types in newborns: autonomic seizures and behavior arrest.³

Seizures in newborns start in one area of the brain (focal onset).³ Seizure signs in general can include eye movements, drooling, a temporary stop in breathing, sudden muscle spasms and jerking limbs.²

What are silent seizures in babies?

The phrase "silent seizure" can mean two different things:

1. Seizures with no visible signs. Many newborn seizures are electrographic-only: the EEG shows a seizure, but the baby looks normal.³
2. Seizures that are easy to miss. Some seizures cause only a staring spell, and these may go unnoticed.² In newborns, subtle seizures such as eye deviation or mouth movements are the most common type.¹

Because of this, an EEG has a central role in diagnosing seizures in newborns.³

What are the signs of seizures in babies while sleeping?

The most common sleep-time worry is benign neonatal sleep myoclonus. Healthy babies can have repetitive, rhythmic jerks that happen only during sleep. The jerks stop when the baby wakes up, and the condition traditionally goes away by 3 months of age, with no lasting effects, although in about a third of babies it lasted longer. Rocking or repetitive sounds can set it off.¹⁰ It does not need treatment.¹

Holding the limbs is not a reliable test for this one: in the review, sleep myoclonus jerks stopped, or even got worse, when the limbs were held.¹⁰ The useful sign is that sleep myoclonus stops once the baby is awake. Jerks that carry on after your baby is fully awake do not fit that pattern and should be checked by a doctor.

Infantile spasms often come in a series just after the baby wakes up.⁸ When spasms are suspected, experts recommend a long video-EEG that records both awake and asleep.⁹ One thing that recording looks for is the EEG pattern called hypsarrhythmia.

Seizure or normal baby movement?

Newborns often make movements that are not seizures, and these should not be confused with seizures.¹

• Jitteriness. The most common look-alike. It is a quick, even trembling on both sides, without changes in heart rate, breathing or color, and it stops when the limb is gently bent and held. It does not need treatment.¹
• Benign sleep myoclonus. Jerks only during sleep that stop when the baby wakes (above).¹⁰
• Exaggerated startle (hyperekplexia). A very exaggerated startle response set off by sound, sight or touch.¹

These signs point more toward a seizure and should be checked by a doctor: movements in an awake baby that do not stop when you gently hold the limb, eyes that stay turned to one side, a change in color or breathing, a series of sudden bends or stiffenings, or a baby who does not respond to your voice during the episode.^1,8,11 Only a doctor, often with an EEG, can say for sure.

What causes seizures in babies?

In the US study of newborns monitored with video-EEG, the most common causes were brain injury from lack of oxygen and blood flow around birth (hypoxic-ischemic encephalopathy, 38%), stroke (18%) and bleeding in the brain (11%).⁵

Other causes of seizures in babies include abnormal levels of sugar or sodium in the blood, infections such as meningitis or encephalitis, brain problems present before birth, head injury, and inherited conditions such as phenylketonuria (PKU). Sometimes no cause is found.² Genetic conditions can also cause seizures in babies. Tuberous sclerosis complex, for example, causes seizures in about 85% of people who have it, most starting in the first year of life.¹²

Seizures in babies with and without fever

Most of the causes above produce seizures without fever. A febrile seizure is a seizure set off by a fever of 100.4 °F (38 °C) or higher. Febrile seizures happen most often in otherwise healthy children between 6 months and 5 years old.¹¹ The American Academy of Pediatrics guideline on simple febrile seizures covers children from 6 through 60 months.¹³

A simple febrile seizure stops on its own within a few seconds to 10 minutes, and there is no evidence that simple febrile seizures cause brain damage or epilepsy. A seizure that lasts longer than 15 minutes, affects only one part of the body, or comes back in the same illness is not a typical febrile seizure. In babies and young children, doctors must rule out other causes of a first seizure, especially meningitis, and more tests may be needed in babies under 9 months.^11,13

What should I do during my baby's seizure?

Most of what helps is keeping your baby safe and watching closely:^2,4,11

• Stay calm and stay with your baby.
• Lay your baby down in a safe area, cleared of anything sharp.
• Turn your baby gently onto one side, with the mouth pointing down, especially if there is vomit or saliva.
• Loosen tight clothing around the neck.
• Time the seizure.
• Do not hold your baby down or try to stop the movements.
• Do not put anything in your baby's mouth.
• Do not give food or drink until your baby is fully alert.

It is normal for a child to be sleepy or confused for a short time after a seizure.¹¹

When should I call 911?

Call 911 or your local emergency number if:^2,4

• this is your baby's first seizure
• the seizure lasts longer than 5 minutes
• another seizure starts soon after the first
• your baby has trouble breathing, or does not wake up or return to normal afterward
• your baby was injured, or the seizure happened in water

For a febrile seizure, MedlinePlus says to call 911 if it lasts several minutes, and if it ends quickly, to take your child to an emergency room once it is over.¹¹

Possible infantile spasms are different. Clusters of brief bends or stiffenings usually do not meet the 911 criteria above, but they still need urgent medical contact the same day: call your baby's doctor right away and do not wait for a routine visit. Experts advise seeing a pediatric neurologist as early as possible if the events on video look suspicious.⁹ Speed matters, because a longer delay to treatment is linked to lower development scores.^14,15

Why filming your baby's seizure helps

Make sure your baby is safe first. Then, if someone can, record a video on a phone. In a study, doctors watched 12 real infant cases. They made more correct diagnoses after seeing home videos than from descriptions alone, for both seizures and harmless look-alikes.¹⁶ Infantile spasms experts also say parent videos help the evaluation.⁹

Timing the seizure matters too, because a seizure longer than 5 minutes needs emergency help.⁴

How are seizures in babies diagnosed?

• EEG. An EEG records the brain's electrical activity. In newborns it is central to diagnosis, because many seizures are visible only on the EEG.³ A newborn with seizures should be monitored in hospital with continuous video-EEG if possible.¹ For suspected spasms, a long video-EEG awake and asleep is recommended.⁹
• Looking for the cause. Doctors check quickly for problems that can be treated right away, such as an acute metabolic problem, and in babies and young children they rule out infections such as meningitis.^1,11
• Simple febrile seizures usually do not need an EEG, blood tests or brain imaging; the focus is on the cause of the fever.¹³

If your baby is diagnosed with infantile spasms

Infantile spasms, including West syndrome, need prompt treatment.⁷ Guidelines recommend hormonal treatment (ACTH or steroids) or vigabatrin, and every guideline in a worldwide review recommends vigabatrin first when tuberous sclerosis is the cause.^17,18

If vigabatrin is prescribed, accurate doses from day one matter: in a large US study, the median time to response on vigabatrin was 3 days.¹⁹ Every vigabatrin form is the same medicine.²⁰ The ready-to-use liquid (Vigafyde) is labeled, like other vigabatrin forms, for infantile spasms of any cause from 1 month to 2 years. It needs no mixing before giving it to your baby; in one small study funded by its maker, doses prepared from it were more accurate than doses mixed from powder.^20,21 Vigabatrin can cause permanent vision loss, so eye checks are required.²⁰

Summaries of the key studies are on the research page, and answers to common questions are in the vigabatrin FAQ.