Seizures in Newborns: What Are the Long-Term Effects?

A newborn seizure is a medical event caused by a sudden, abnormal electrical disturbance in the brain, occurring within the first 28 days of life. Unlike the dramatic convulsions often seen in older individuals, seizures in newborns can be subtle, with signs like repetitive blinking, staring, or bicycling movements of the legs. A seizure is not a disease itself but is a symptom of an underlying issue affecting the brain. Because the newborn brain is developing rapidly, these events indicate a potential problem with the central nervous system and prompt a search for the root cause.

Potential Developmental and Motor Outcomes

The occurrence of seizures in a newborn can have lasting effects on the parts of the brain responsible for movement and physical growth. These abnormal electrical discharges can disrupt the development of motor pathways, leading to a range of physical challenges. The specific outcomes often depend on the location and extent of the underlying brain injury that caused the seizures.

One of the more significant potential outcomes is cerebral palsy, a group of disorders that affect a person’s ability to move and maintain balance. This condition results from damage to the motor control centers of the developing brain. Following neonatal seizures, a child might be diagnosed with cerebral palsy if they show difficulties with muscle tone or coordinated movements, such as muscles being too stiff (hypertonia) or too loose (hypotonia).

Beyond a specific diagnosis like cerebral palsy, many children who experience newborn seizures may face more general motor delays. These can include challenges in reaching developmental milestones such as gaining head control, rolling over, sitting up, and walking. Difficulties with fine motor skills, like grasping objects, may also become apparent as the child grows.

Cognitive and Behavioral Challenges

Beyond physical challenges, neonatal seizures can influence a child’s cognitive and behavioral development. The brain regions governing learning, memory, and executive functions are vulnerable during the newborn period, and seizure activity can disrupt their formation. This may lead to long-term difficulties that become more evident as a child reaches school age.

One potential consequence is a global developmental delay or intellectual disability, where a child does not meet developmental milestones in several areas. As they grow, specific cognitive challenges may emerge, such as problems with memory retention, information processing, and problem-solving skills. Learning new academic concepts may be more difficult, requiring specialized educational support.

There is also an increased likelihood of behavioral challenges for children with a history of neonatal seizures. Some studies suggest a higher incidence of attention-deficit/hyperactivity disorder (ADHD), characterized by issues with inattention, impulsivity, and hyperactivity. Difficulties with emotional regulation and social functioning can also occur.

Risk of Future Epilepsy

It is important to distinguish between a neonatal seizure, an acute symptom, and epilepsy, a condition defined by two or more unprovoked seizures. A seizure in a newborn does not automatically mean the child will develop epilepsy, but it does increase the risk.

Research indicates that about 20.4% of children who experience neonatal seizures will be diagnosed with epilepsy by early adulthood. This risk is substantially higher than in the general population, where the risk is just over 1%. The highest risk for developing epilepsy is within the first year of life.

However, this also means that the majority of newborns with seizures will not develop epilepsy. The likelihood of future epilepsy is heavily influenced by the underlying cause of the neonatal seizures. The presence of a brain injury like a stroke or malformation is associated with a higher risk.

Factors Influencing Long-Term Prognosis

The long-term outlook for a child who has experienced neonatal seizures varies significantly. The single most important factor is the underlying cause of the seizures. A seizure is a symptom, and the prognosis is tied directly to the nature and severity of the root problem, such as:

• Hypoxic-ischemic encephalopathy (HIE), a brain injury from oxygen deprivation
• An infection like meningitis
• A stroke
• A metabolic disorder
• A congenital brain malformation

The characteristics of the seizures themselves also provide prognostic clues. The type, frequency, and duration—known as the seizure burden—can indicate the severity of the brain irritation. Status epilepticus, a state of prolonged or repetitive seizures, is associated with more adverse outcomes. How well the seizures respond to medication is another indicator.

Diagnostic tests are fundamental for determining the extent of brain injury. An electroencephalogram (EEG) records the brain’s electrical activity to confirm seizures and evaluate background brain function, as abnormal activity is a strong predictor of poor outcomes. Furthermore, brain imaging, particularly a magnetic resonance imaging (MRI) scan, provides a detailed picture of the brain’s structure, revealing any damage or malformations that influence the prognosis.

Therapeutic Interventions and Monitoring

Following a neonatal seizure, management focuses on a comprehensive approach to support the infant’s development. This care is often coordinated by a primary physician who works with a multidisciplinary team of specialists. This team approach ensures that all aspects of the child’s health and development are monitored and managed cohesively.

Specific therapies are tailored to the child’s individual needs. Physical therapy is recommended to address motor delays, helping with muscle tone, strength, and coordination to achieve milestones like sitting and walking. Occupational therapy focuses on improving fine motor skills and daily activities. A speech-language pathologist will provide targeted interventions if speech and feeding issues arise.

Regular follow-up is a part of post-seizure care. Neurological appointments and routine developmental screenings are scheduled to track the child’s progress and identify any new concerns early. This continuous monitoring allows the medical team to adjust therapies as the child grows and their needs change, which is linked to better long-term outcomes.