The experience of witnessing an infant exhibit unusual movements can cause considerable anxiety for any caregiver. A seizure is a transient event caused by a sudden, uncontrolled burst of abnormal electrical activity within the brain’s network of cells. Unlike the dramatic, full-body convulsions often seen in adults, seizures in babies, particularly newborns, can manifest in ways that are far more subtle and easily mistaken for normal behaviors. Understanding these differences is an important step in protecting an infant’s developing nervous system and securing prompt medical attention.
Recognizing the Subtle and Obvious Physical Indicators
Seizures in infants do not always present as a generalized, rhythmic shaking of the entire body. The immaturity of a baby’s brain often results in more localized or focal seizures, which can be difficult to identify without close observation. These subtle signs often involve repetitive, automatic movements of the face and mouth.
Caregivers may observe rapid eye movements, such as fluttering eyelids, a fixed stare, or the eyes rolling upward or to one side. Abnormal mouth movements are also common, including repeated lip-smacking, tongue protrusion, or a sucking motion unrelated to feeding. These subtle indicators may come and go quickly, sometimes lasting only a few seconds.
The extremities can also display signs of a subtle seizure with repetitive, non-purposeful movements. These might look like a sustained bicycling or pedaling motion of the legs, or a thrashing movement that continues without external stimulation. Some seizures can cause a sudden change in muscle tone, presenting as brief, sustained stiffening or a sudden, temporary limpness.
While less common, generalized seizures involve both sides of the body and are typically more noticeable. The infant may suddenly stiffen their body and limbs in a tonic phase, sometimes holding their arms and legs in an awkward, fixed position. This prolonged stiffness may be followed by a clonic phase, characterized by sustained, rhythmic jerking of the arms and legs. Generalized seizures are also associated with a loss of consciousness or unresponsiveness during the event.
Seizure Mimics: Distinguishing Normal Infant Behavior
Many movements that appear concerning to a new parent are actually normal, temporary reflexes or behaviors of a developing nervous system. One frequently mistaken movement is the Moro reflex, often called the startle reflex. This common primitive reflex involves the baby suddenly throwing out their arms, arching their back, and then pulling their limbs back in, typically triggered by a loud noise or a sensation of falling.
Another common mimic is benign sleep myoclonus, which consists of brief, lightning-like jerks of the limbs that occur only when the baby is falling asleep or in a state of quiet sleep. A distinguishing factor is that these movements will stop immediately if the baby is gently woken up or stimulated. True seizures, by contrast, are generally not interrupted by waking the baby.
Infants may also display jitteriness, which is a tremor-like movement, especially when they are crying or cold. To differentiate this from a seizure, gently restrain the shaking limb; jitteriness will cease when the limb is held or repositioned, while a seizure’s rhythmic movement will continue despite restraint. Certain gastroesophageal reflux episodes, known as Sandifer syndrome, can also cause infants to arch their backs and stiffen, but these episodes are typically associated with feeding.
First Aid During a Seizure and When to Call 911
The immediate priority when a baby is having a seizure is to ensure their safety and prevent injury. Place the baby on a safe, flat surface, such as the floor, and clear away any hard or sharp objects from their immediate vicinity. Turning the baby gently onto their side is important, as this position helps prevent aspiration if they vomit and keeps the airway clear.
Avoid trying to stop the movements by restraining the baby’s limbs, as this can inadvertently cause injury. Never put anything into the baby’s mouth, as this can cause injury or obstruct the airway.
Timing the event is crucial information for medical professionals; note the exact time the seizure begins and ends. Most seizures in infants stop on their own within a few minutes. Emergency medical services should be called immediately if the seizure lasts longer than five minutes, as this may indicate a serious condition.
Call 911 or your local emergency number if this is the baby’s first seizure, even if it is brief. Immediate medical attention is also necessary if the baby appears to be having trouble breathing, turns blue, or does not wake up or become responsive immediately after the movement stops. Providing a detailed report of the duration and specific physical signs observed will assist the medical team in diagnosis and treatment.