Baby seizures often look nothing like what most people picture. Instead of dramatic full-body convulsions, infant seizures frequently involve subtle, easy-to-miss movements like repetitive eye fluttering, rhythmic lip smacking, or brief episodes of staring and going completely still. Knowing what to look for is critical because most neonatal seizures are focal, meaning they affect only one part of the brain or body at a time, since a baby’s brain isn’t yet developed enough to spread electrical activity widely.
Subtle Seizures: The Easiest to Miss
The most common type of seizure in full-term newborns is called a “subtle” seizure, and the name is accurate. These episodes can look so ordinary that parents and even medical staff sometimes dismiss them. The hallmark signs include:
- Eye movements: Random or roving eye movements, eyelid blinking or fluttering, eyes rolling upward, fixed staring, or sudden wide-eyed opening
- Mouth movements: Repetitive sucking, lip smacking, chewing, or tongue protruding that isn’t linked to feeding
- Leg movements: Bicycling or pedaling motions of the legs that the baby doesn’t seem to be doing on purpose
- Breathing changes: Long pauses in breathing (apnea) that seem to come out of nowhere
- Thrashing: Struggling or thrashing movements that look different from normal fussiness
What makes these tricky is that healthy babies do some of these things normally. The key difference is pattern and context. A seizure-related movement tends to be rhythmic, repetitive, and resistant to gentle restraint. A baby who is smacking their lips during a seizure won’t stop when you touch their face or offer a pacifier, and the movements will look mechanical rather than purposeful.
More Obvious Physical Signs
Some seizures produce movements that are easier to recognize. Clonic seizures involve rhythmic jerking of one or more limbs. These jerks may migrate from one limb to another or affect one side of the body. They’re typically brief but unmistakable once you’ve seen them. Tonic seizures cause sudden stiffening of the body or limbs. The baby may arch their back or extend their arms rigidly. Myoclonic seizures look like quick, lightning-fast jerks of the arms or legs, similar to a hiccup-like twitch but more forceful.
Generalized tonic-clonic seizures, the kind most people associate with epilepsy in older children and adults, are actually uncommon in babies. The immature brain typically produces smaller, more localized episodes.
Seizures Without Any Movement at All
Some infant seizures have no visible motor component. These “nonmotor” seizures can involve sudden changes in heart rate, blood pressure, or breathing patterns, or what’s called behavior arrest, where the baby abruptly stops moving and becomes unresponsive. The baby may go completely still, eyes open but not tracking, for several seconds to a minute. These are among the hardest seizures to identify because they can look like a baby simply zoning out or falling asleep. If your baby repeatedly has moments where they seem to “check out” and can’t be roused with gentle stimulation, that warrants medical attention.
Infantile Spasms: A Special Warning
Infantile spasms are a specific, serious type of seizure that typically begins between 3 and 12 months of age. They can look deceptively mild, which is why they’re often mistaken for a normal startle reflex or colic. The hallmark movements include sudden bending of the arms and legs forward, arching the back, nodding the head repeatedly, eye rolling, or a brief full-body tensing. Each spasm lasts only one to two seconds.
The critical clue is clustering. Infantile spasms almost always come in groups, with 5 to 10 seconds of calm between each spasm. A cluster can contain dozens of individual spasms. They most often happen right after the baby wakes up. If you notice your baby having repeated brief “startles” in a series, especially upon waking, this is not a normal startle reflex. Normal startle reflexes are triggered by a sudden noise or movement and happen once. Infantile spasms are unprovoked and repeat. This type of seizure requires urgent evaluation because early treatment significantly affects outcomes.
Sleep Twitches vs. Seizures
Babies twitch a lot during sleep, and most of the time it’s completely harmless. Benign sleep myoclonus is a well-documented phenomenon where healthy newborns have jerky movements during light sleep. These jerks can be focal (one limb) or involve the whole body, and they can happen quite rapidly, up to 15 times per second, which understandably alarms parents.
The single most reliable way to tell the difference: benign sleep twitches stop the moment the baby wakes up. If you gently rouse your baby during an episode and the movements cease immediately, it’s almost certainly not a seizure. Sleep myoclonus also occurs specifically during non-REM (lighter) sleep, and babies who experience it are otherwise neurologically normal, developing on schedule with no other concerning signs. If the jerking continues after the baby is awake, or if the episodes are accompanied by changes in breathing, eye deviation, or unresponsiveness, those are red flags.
Febrile Seizures in Older Babies
Once babies reach about six months of age, they become susceptible to febrile seizures, which are seizures triggered by fever. These can occur in children from 6 months to 5 years old when a fever reaches 100.4°F (38°C) or higher. Febrile seizures are the most common type of seizure in this age group and, while terrifying to witness, are usually harmless. A simple febrile seizure typically lasts under five minutes, involves the whole body, and happens only once during an illness. The child may go stiff, shake, and become unresponsive, then return to normal relatively quickly afterward.
What Happens After a Seizure
The period immediately following a seizure is called the postictal phase, and recognizing it can help confirm that what you witnessed was indeed a seizure. Babies typically become very sleepy or lethargic afterward. They may seem disoriented, have difficulty feeding, or be unusually fussy. This recovery period can last anywhere from a few minutes to several hours. An infant who was active and alert, then had an unusual episode, and afterward becomes deeply sleepy or difficult to rouse has likely experienced a seizure.
What to Record for Your Doctor
If you think your baby is having seizures, the most valuable thing you can do is capture the episode on video with your phone. Seizures are often over by the time a doctor can observe them, and a video provides information that no verbal description can match.
Beyond video, track these details each time an episode occurs:
- Timing: When it started, how long it lasted, whether the baby was awake or asleep
- Body involvement: Which side of the body was affected, whether movements were on one side or both, whether they were symmetrical
- Muscle tone: Whether the baby went stiff, went limp, or alternated between the two
- Eyes: Direction of gaze, whether the eyes deviated to one side or rolled upward
- Breathing: Any pauses, color changes, or signs of difficulty
- Recovery: How long until the baby returned to normal behavior, whether they slept afterward and for how long
- Triggers: Whether the baby was tired, unwell, or had just woken up
This level of detail helps doctors determine what type of seizure occurred and what evaluation is needed.
When It Becomes an Emergency
Most seizures end on their own within one to three minutes. Call emergency services if a seizure lasts five minutes or longer, if one seizure follows another without the baby fully recovering in between, if the baby’s breathing becomes labored or their skin turns blue, or if the baby appears to be choking. A first-time seizure in any baby also warrants prompt medical evaluation, even if the episode was brief and the baby seems fine afterward.