If you have seen your baby make a quick, repeated movement that gave you a strange feeling in your gut, trust that feeling. Infantile spasms are easy to miss. They can look like a startle, a tummy ache, or a baby being a baby. They are also a seizure disorder that pediatric neurologists treat within days of the first phone call.
If your baby is having these spells, call your pediatrician today, or go to the emergency room. Infantile spasms are one of the few things in a baby's first year that doctors want to see now, not at the next well visit.
Key Takeaways
- Infantile spasms are a rare but serious type of seizure that usually begins between 3 and 12 months of age, most often around 4 to 7 months.
- The spasms are brief, lasting 1 to 2 seconds, and come in clusters of several in a row, often right after a baby wakes up.
- West syndrome is the name for the combination of infantile spasms, a specific chaotic brain-wave pattern called hypsarrhythmia, and a slowing or loss of developmental skills.
- This is a medical emergency. Early diagnosis and treatment give your child the best chance at a good outcome, so spasms should be evaluated within days, not weeks.
- First-line treatments include ACTH (a hormone given by injection), oral steroids, and vigabatrin (an anti-seizure medicine), with the ketogenic diet used in some cases.
What Are Infantile Spasms?
Infantile spasms are a type of epileptic seizure that affects babies, usually in their first year of life. They are also known as epileptic spasms or, when they occur with certain other findings, West syndrome.
Each spasm is short. The body stiffens or jerks for a second or two, and then it is over. They rarely come alone. According to the Cleveland Clinic, they happen in clusters, one after another with brief pauses in between, often just as a baby is waking up or falling asleep.
Infantile spasms are rare, affecting fewer than 1 in 1,000 babies, with roughly 2,000 to 2,500 new cases diagnosed in the United States each year. The rarity is part of the danger. Most parents have never heard of them, and the movements are small enough to explain away as reflux or a startle, while the seizure activity behind them disrupts the brain during the months a baby learns to sit, reach, and babble.
West Syndrome vs. Infantile Spasms
Infantile spasms describe the seizure itself. West syndrome describes a specific combination of three things that often appear together.
The three features of West syndrome are:
- Infantile spasms (the clusters of brief, stiffening seizures)
- Hypsarrhythmia, a chaotic and disorganized pattern seen on an EEG brain-wave test
- Developmental regression or delay, meaning a baby stops gaining new skills or loses skills they already had
Not every child with infantile spasms has all three features, which is why doctors run an EEG and track development before naming the diagnosis. When the full picture is present, the diagnosis is West syndrome. Either way, the urgency and the treatment approach are similar. For how spasms sit alongside other seizure types in childhood, see our parent's guide to children's seizures.
What Do Infantile Spasms Look Like?
A spasm is a sudden, brief stiffening of the body, and it follows a pattern you can learn to recognize.
A typical spasm looks like one or more of these:
- The head drops forward and the chin tucks toward the chest
- The arms fling out to the sides or pull inward, as if startled
- The legs draw up toward the belly
- The body bends forward at the waist, like a quick crunch or a jackknife
- Sometimes the movement is subtle: a small head nod, an eye roll, or a brief shrug
Each movement lasts only a second or two. Then the baby relaxes, and a few seconds later it happens again. The Cleveland Clinic notes that pauses between spasms in a cluster typically run about 5 to 10 seconds, and a full cluster can last several minutes.
Many parents search for videos of infantile spasms because the movements are hard to describe in words. Pediatric neurology organizations and children's hospitals publish reference videos that show what a spasm looks like on a real baby. Watch a few. If what you see on screen resembles what your baby is doing, call the same day rather than waiting to see if it passes.
Babies often cry or seem dazed right after a cluster. Parents frequently describe knowing something was wrong days before they could put words to it.
How Infantile Spasms Differ From a Normal Startle (Moro Reflex)
Newborns and young babies startle. A loud sound, a sudden movement, or the feeling of falling triggers the Moro reflex: the baby throws out both arms, arches slightly, then pulls back in. That is normal and healthy.
A startle answers something, a noise or a bump or a change in position. Infantile spasms come out of nowhere, with no trigger at all. A startle is one event; spasms repeat in clusters with short pauses between them. The Moro reflex also fades as a baby grows, mostly gone by 4 to 6 months, right around the age infantile spasms tend to begin.
Sleep is the other clue. Spasms cluster around sleep transitions, especially the minutes just after waking. A startle keeps no schedule.
If you are not sure, record it and call. A short phone video taken in good light, with your baby's whole body in the frame, tells a pediatrician more than any description you could give over the phone. Nobody expects you to diagnose this. Noticing it is the whole job.
How Fast Doctors Need to See a Baby With Spasms
The same seizure activity that causes the visible spasms also disrupts the developing brain in the background, and longer delays before treatment are linked to worse developmental outcomes.
Pediatric neurologists therefore treat infantile spasms as an emergency. They work to stop the spasms and clear the hypsarrhythmia pattern within days. Babies diagnosed and treated early have a better chance of catching back up developmentally. Those who go untreated for weeks or months are at higher risk for lasting delays, intellectual disability, and other seizure types later in childhood.
A parent who recognizes the pattern and asks for an EEG this week changes what the next year looks like. No pediatrician will fault you for asking.
How Doctors Diagnose Infantile Spasms
The key test for infantile spasms is an EEG (electroencephalogram), a painless test that records the brain's electrical activity using small sensors placed on the scalp.
In a baby with infantile spasms, the EEG often shows hypsarrhythmia, a high-voltage, chaotic, disorganized pattern of brain waves. The Epilepsy Foundation describes hypsarrhythmia as a hallmark finding that helps confirm the diagnosis. Doctors often want an EEG that captures both wake and sleep, because the abnormal pattern can be clearest during sleep.
Beyond the EEG, the care team usually works to find a cause. That evaluation can include brain imaging (most often an MRI), genetic and metabolic testing, a detailed review of pregnancy and birth history, and bloodwork.
Infantile spasms have many possible causes, including genetic conditions, brain malformations, prior brain injury, and infections. In a meaningful share of children, no single cause is ever found. Knowing the cause, when it can be identified, helps the team predict what else to watch for, but it does not change the immediate priority: stop the spasms fast.
How Infantile Spasms Are Treated
Treatment aims to stop the spasms and normalize the EEG quickly. Which medicine comes first depends on your child's situation.
The most common first-line treatments are:
- ACTH (adrenocorticotropic hormone), given as an injection, often at home by a trained parent over several weeks
- Oral steroids such as prednisolone, used as a hormone-based alternative to ACTH
- Vigabatrin, an anti-seizure medication that is especially effective when the spasms are linked to a condition called tuberous sclerosis
When first-line medicines do not fully control the spasms, doctors may turn to the ketogenic diet, a carefully managed high-fat, low-carbohydrate medical diet, or to other anti-seizure medications. In select cases where a specific area of the brain is driving the seizures, epilepsy surgery is an option.
Doctors do not wait long to find out if a treatment is working. The usual check comes at about two weeks, because a trial that drags on past that rarely starts helping and does add side effects. If the spasms have not stopped and the EEG has not cleared by then, the team switches to the next option. These are powerful medicines with real risks, so a pediatric neurologist prescribes them and watches your child closely through the course.
What's the Prognosis for a Child With Infantile Spasms?
Prognosis depends heavily on the cause and on how quickly treatment begins. Some children respond well, stop having spasms, and go on to develop typically. Others continue to face seizures and developmental challenges.
According to the Cleveland Clinic, about 6 in 10 children with infantile spasms continue to have seizures or developmental difficulties over time. Many later develop other forms of epilepsy, and some have lasting effects on learning, movement, vision, or speech. Children whose spasms have a clear underlying cause, especially a structural brain difference, tend to face a harder road than those with no identified cause.
Two things consistently improve the odds. One is speed, and that is the part you control: the sooner the EEG happens, the sooner treatment starts. The other is what comes after, the years of neurology visits, medication schedules, and developmental support that keep a child gaining skills.
Where Daily Care Fits for a Child With a Seizure Disorder
A diagnosis of infantile spasms changes daily life. There are new medications on a schedule, neurology follow-ups, EEGs to repeat, and constant watchfulness for new seizures or missed milestones. Many of these children also have co-occurring conditions, such as cerebral palsy or low muscle tone, that bring their own care needs.
A typical daycare cannot take a child on a seizure action plan, and a parent handling it alone at home is on duty around the clock.
PPEC (Prescribed Pediatric Extended Care) is a type of medical daycare where skilled pediatric nurses care for children with complex medical needs throughout the day. For a child with a history of infantile spasms, that means nurses who know the seizure care plan, watch for new spasm activity, give medications on time, and respond fast if something changes. Children play and make friends in a room built for them, while families get a real workday or a real break back. You can read more on our conditions overview, including dedicated pages for infantile spasms and seizure disorders and epilepsy and recurrent seizures.
When to Call Your Doctor Today
Some symptoms can wait for a regular appointment. Infantile spasms cannot. Call your pediatrician right away, or go to the emergency room, if you notice:
- Clusters of brief stiffening, jerking, or bending movements, especially after your baby wakes up
- Repeated head drops, arm flings, or body folds that happen several times in a row
- Any new movement pattern that gives you that gut-level sense that something is wrong
- A baby who has stopped smiling, babbling, reaching, or doing things they used to do
- Subtle, repeated eye rolling, shrugging, or head nodding that comes in bursts
Bring a short video if you can capture one safely. Ask directly whether your child needs an EEG to check for infantile spasms. Parents almost always spot this before anyone else does.
How Spark Pediatrics Supports Families
Spark Pediatrics operates PPEC centers staffed by nurses with deep experience caring for children with seizure disorders and other complex needs. For a family in the first weeks after an infantile spasms diagnosis, that support includes:
- Skilled pediatric nurses who follow your child's seizure care plan and respond quickly to changes
- Dedicated therapy spaces with medical oversight, where your child's own therapists can work during the day
- Coordination with your neurologist and care team, so the daycare day reinforces the medical plan
- 100% Medicaid coverage, with our team handling the paperwork and authorizations
Spark operates PPEC centers in Florida and Texas, and families in those states can enroll once their child qualifies for Medicaid coverage.
Find a Spark Pediatrics center near you, or get started with enrollment. Not sure whether your child qualifies for Medicaid coverage? Check eligibility in a few minutes.
You can call before the paperwork is sorted out. Our team takes the authorizations from there.
Frequently Asked Questions
What is the difference between infantile spasms and West syndrome?
Infantile spasms are the seizures themselves: brief, repeated stiffening or bending movements that come in clusters. West syndrome is the name for a combination of three findings that often appear together: infantile spasms, a chaotic EEG pattern called hypsarrhythmia, and a slowing or loss of developmental skills. A child can have infantile spasms without meeting the full definition of West syndrome, which is why EEG testing matters.
At what age do infantile spasms usually start?
Infantile spasms most often begin between 3 and 12 months of age, with the average onset around 4 to 7 months. That overlaps with the age when the normal startle (Moro) reflex is fading, so spasms are easy to mistake for typical baby movements. Any cluster of brief, repeated stiffening movements in this age range needs evaluation within days.
How can I tell infantile spasms apart from a normal startle?
A normal startle answers something, like a loud noise or a sudden movement, and happens once. Infantile spasms come with no trigger, repeat in clusters of several in a row, and tend to hit around waking from sleep. If the movements arrive in bursts over several minutes, or your baby seems to be losing skills, record a short video and call your doctor.
Are infantile spasms an emergency?
Yes. Doctors treat infantile spasms as a medical emergency because the underlying seizure activity can interfere with brain development, and delays in treatment are linked to worse outcomes. Spasms need evaluation within days, not weeks. Call your pediatrician right away, or go to the emergency room, if you think your baby is having them.
Can infantile spasms be cured?
Many children respond well to treatment, with the spasms stopping and the EEG returning to a more normal pattern, especially when treatment starts early. Outcomes still vary widely and depend heavily on the cause and on how quickly care begins. Some children go on to develop typically. Others continue to have seizures or developmental challenges.
Does Medicaid cover care for a child with a seizure disorder?
Medicaid covers most evaluation, EEG testing, imaging, medication, and therapy services. For children who qualify for Medicaid in Florida and Texas, PPEC programs cover daily skilled nursing, therapy space, and medical oversight at no out-of-pocket cost to families. You can check whether your child qualifies in a few minutes.