What Causes Seizures in Newborns?

Newborn seizures are abnormal, involuntary electrical discharges in the immature brain that manifest as transient changes in behavior, motor activity, autonomic function, or consciousness. Unlike seizures in older children or adults, neonatal seizures often lack classic convulsive features—such as rhythmic jerking or tonic posturing—and may instead present subtly with eye deviations, repetitive blinking, lip smacking, apnea, or bicycling movements. These atypical presentations reflect the structural and functional immaturity of the neonatal central nervous system, particularly underdeveloped cortical inhibition and synaptogenesis.

The underlying causes of neonatal seizures are diverse and frequently urgent. Hypoxic-ischemic encephalopathy (HIE) remains the most common etiology, typically occurring after perinatal asphyxia. Other critical causes include intracranial hemorrhage, stroke (both ischemic and hemorrhagic), central nervous system infections (e.g., bacterial meningitis or herpes simplex virus encephalitis), metabolic disturbances (such as hypoglycemia, hypocalcemia, hyponatremia, or inborn errors of metabolism), and genetic epileptic encephalopathies. Prompt identification and targeted management of the root cause are essential—not only to control seizure activity but also to mitigate secondary neuronal injury.

Diagnosis hinges on clinical suspicion combined with electroencephalography (EEG), preferably continuous video-EEG monitoring, which is the gold standard for detecting electrographic seizures—many of which are clinically silent. Neuroimaging, especially brain MRI, is crucial for identifying structural abnormalities, while laboratory evaluation must include blood glucose, electrolytes, calcium, magnesium, ammonia, lactate, blood gas analysis, infectious studies (CSF analysis, blood cultures, HSV PCR), and, when indicated, metabolic and genetic testing.

Treatment begins with stabilizing vital functions—ensuring adequate oxygenation, ventilation, circulation, and correcting reversible metabolic derangements. First-line antiseizure medication is typically phenobarbital; if ineffective, second-line agents such as levetiracetam or pyridoxine (particularly in suspected vitamin B6–dependent epilepsy) may be considered. In refractory cases, intensive care support—including therapeutic hypothermia for HIE, antimicrobial therapy for infection, or neurosurgical intervention for mass lesions—may be required. Long-term neurodevelopmental follow-up is mandatory, as neonatal seizures are associated with increased risks of epilepsy, cerebral palsy, cognitive delay, and learning disabilities.