Newborn epilepsy, also referred to as neonatal seizures, describes epileptic fits occurring from birth through the first 28 days of a full-term infant’s life. The first week of life, especially the initial one to two days, carries the highest risk for seizure development in newborns across their lifespan.
Recognizing the Signs
Newborn seizures can be subtle, making them challenging to distinguish from typical newborn behaviors. Subtle signs include changes in breathing patterns, rhythmic movements of the eyelids or lips, or repetitive actions like sucking, smacking, chewing, or tongue sticking out.
Movements indicating a seizure may mimic normal infant activities, such as bicycling or pedaling motions of the legs. However, if these movements are repeated, last for several minutes, or involve thrashing or struggling, they may signal a seizure. More overt signs include rhythmic jerking of one or both arms or legs (clonic seizures), or sudden, shock-like jerks of the head or limbs (myoclonic seizures).
Another type, tonic seizures, involves sustained stiffening or tightening of muscles in one area or the entire body, making the baby appear rigid. During a tonic seizure, the baby’s eyes or head might turn to one side. These more pronounced signs, along with any pauses in breathing, warrant immediate medical attention.
Understanding the Causes
Newborn epilepsy can arise from various underlying issues. A common cause is hypoxic-ischemic encephalopathy (HIE), which involves a lack of oxygen to the brain before or during birth, accounting for approximately 33% of neonatal seizures. Brain injury, including stroke before or after birth, or bleeding in the brain such as intracranial or intraventricular hemorrhage, can also trigger seizures.
Metabolic imbalances, such as low levels of glucose, calcium, or magnesium in the blood, also contribute. Inborn errors of metabolism, genetic conditions affecting chemical processes, can also lead to seizures. For instance, pyridoxine dependency, a rare vitamin B6 deficiency, is a treatable metabolic cause.
Infections affecting the central nervous system, like bacterial meningitis or viral encephalitis, are known causes of newborn seizures. Genetic factors, including inherited conditions or new gene mutations, can predispose an infant to epilepsy. Rarely, seizures may be linked to drug withdrawal in babies whose mothers had substance use disorder.
Diagnosis and Management
Diagnosing newborn epilepsy begins with a thorough clinical evaluation, but specialized tests are needed to confirm seizures and identify their cause. An electroencephalogram (EEG) is the standard method for diagnosis, as it directly measures the brain’s electrical activity. It detects seizure patterns not obvious through observation.
An amplitude-integrated EEG (aEEG) is a simplified EEG technique used in NICUs for continuous, long-term monitoring. Other diagnostic tests, including blood and urine tests, help pinpoint the underlying cause, checking for metabolic imbalances or infections.
Imaging tests, such as magnetic resonance imaging (MRI) and computed tomography (CT) scans, provide detailed views of the brain’s structure. MRI is useful for detecting subtle brain abnormalities without radiation, helping diagnose conditions like HIE or cerebral malformations. Prompt diagnosis and treatment are important, as prolonged, untreated seizures can lead to permanent brain damage due to reduced oxygen flow and excessive brain cell activity. Treatment often involves anticonvulsant medications like phenobarbital, a common first-line therapy, along with addressing the specific underlying cause identified.
Looking Ahead: Potential Outcomes
The long-term outlook for infants who experience newborn epilepsy varies depending on the underlying cause and the severity of the seizures. About half of babies who experience neonatal seizures may develop epilepsy later in life. Infants with seizures due to brain injuries or developmental abnormalities may face additional complications.
These complications can include cerebral palsy, intellectual disability, or other neurological disorders. Ongoing monitoring and follow-up care with specialists, such such as pediatric neurologists, are important to track the child’s development and manage any recurring seizures. The prognosis is better for full-term infants compared to premature infants.