Newborn seizures are abnormal electrical activity within the brain. They require immediate medical attention as they often signal an underlying medical condition. This article explores how newborn seizures manifest and their common origins.
Recognizing Newborn Seizures
Newborn seizures often present differently from those in older children or adults, appearing as subtle, brief movements that can be challenging to identify. Subtle signs include repetitive mouth movements (sucking, smacking, chewing), unusual eye movements (staring, blinking, fluttering, eyes rolling upwards), bicycling or pedaling leg motions, thrashing, or significant pauses in breathing.
While some seizures are generalized, affecting both sides of the brain and body with widespread stiffening or jerking, many neonatal seizures are focal, originating in one specific area of the brain. Focal seizures may manifest as rhythmic jerking in a single limb or one side of the body, or a sustained stiffening of muscles in a localized area. Some normal newborn behaviors can mimic seizure activity, making medical evaluation crucial for diagnosis.
Common Causes of Newborn Seizures
The immature state of a newborn’s brain makes it more susceptible to abnormal electrical discharges, and several medical conditions can lead to seizures. One of the most frequent causes is hypoxic-ischemic encephalopathy (HIE), a brain injury resulting from a lack of oxygen or blood flow during or around the time of birth. Seizures related to HIE typically appear within the first 12 to 24 hours after birth.
Metabolic disturbances frequently contribute to neonatal seizures. These can include low blood sugar (hypoglycemia), which deprives the brain of essential energy. Imbalances in electrolytes such as low calcium (hypocalcemia) or low magnesium (hypomagnesemia) can disrupt normal brain function and trigger seizure activity. Inborn errors of metabolism, genetic conditions affecting the body’s chemical processes, can lead to seizures and often present with other symptoms like lethargy or poor feeding.
Bleeding within the brain, or intracranial hemorrhage, is another significant cause, especially in preterm infants. Infections, particularly those affecting the brain and spinal cord like meningitis or encephalitis, can cause inflammation and irritation leading to seizures. Structural abnormalities in brain development, known as developmental brain malformations, can predispose a newborn to seizures. Additionally, genetic conditions can play a role, with some syndromes directly linked to seizure susceptibility. Drug withdrawal due to maternal substance use during pregnancy can precipitate seizures as the infant’s system adjusts.
Diagnosis and Treatment Approaches
Confirming a newborn seizure and identifying its underlying cause requires medical evaluation. Electroencephalography (EEG) is a primary diagnostic tool, which measures and records the electrical activity of the brain to detect abnormal seizure patterns. EEG is valuable because some neonatal seizures may not have obvious visible signs or their movements might resemble normal infant behaviors.
Neuroimaging techniques, such as Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) scans, are often used to visualize the brain’s structure and identify any abnormalities like brain injuries, hemorrhages, or malformations. Blood tests are also performed to check for metabolic imbalances, infections, or genetic markers that could be contributing to the seizures. These tests pinpoint the specific cause, guiding the medical team toward an appropriate treatment plan.
Initial treatment focuses on stabilizing the infant and controlling the seizure activity. This often involves addressing the identified underlying cause, such as correcting low blood sugar or electrolyte imbalances. Anti-seizure medications (anticonvulsants) are administered to stop seizures and prevent recurrence.
Prognosis and Long-Term Outlook
The long-term outlook for newborns who experience seizures varies significantly, largely depending on the underlying cause. For instance, seizures caused by transient metabolic issues that are quickly corrected may have a more favorable prognosis compared to those resulting from severe brain injury or complex genetic conditions. The severity and duration of the seizures, as well as how quickly and effectively they are controlled, also influence the prognosis.
While some infants recover without any lasting neurological issues, others may face potential long-term effects. These can include developmental delays, cerebral palsy, or the development of epilepsy later in childhood. Ongoing follow-up care is necessary for newborns who have experienced seizures. This care often involves regular neurological assessments and, when necessary, early intervention services to support development. For many infants, especially those with treatable and temporary causes, achieving typical developmental milestones is possible.