Etiology of Neonatal Seizures

Abstract

After completing this article, readers should be able to: 1. Name the primary causes of neonatal seizures today. 2. Describe the cerebral malformations associated with neonatal seizures. 3. Name the metabolic disorders that are associated with neonatal seizures. 4. Compare the characteristics of familial or idiopathic epilepsies. 5. List appropriate diagnostic tests for neonates who have seizures. 6. Provide a prognosis based on the cause of neonatal seizures. Neonatal seizures are a common problem in the newborn nursery and can occur in infants at any gestational age. Seizures in a newborn infant evoke a sense of urgency among neonatologists because they often indicate a disturbance of the central nervous system (CNS). Causes of neonatal seizures encompass virtually the entire spectrum of neurologic disorders of infancy, but most neonatal seizures today are due to hypoxic-ischemic brain injury and intracranial hemorrhage. The proper treatment of neonatal seizures depends on the cause. For example, neonatal seizures due to a transient metabolic disturbance, such as hypocalcemia or hypoglycemia, are treated by correcting the underlying metabolic derangement. However, seizures due to such transient disturbances are relatively infrequent today because of improved neonatal care. For neonates who have seizures caused by a systemic infection (sepsis) or CNS infection (meningitis and encephalitis), the underlying infection must be treated appropriately. The specific cause also has prognostic implications. More common etiologies of neonatal seizures are discussed in this review (Table 1). As discussed in the review on neonatal electroencephalography (EEG) in this issue of NeoReviews , proper identification of epileptic seizures is important. The most common seizure types are: focal or multifocal clonic, tonic, and myoclonic and subtle. Subtle seizures comprise a variety of motor and autonomic phenomena and are more common in neonates who have severe encephalopathies. However, neonates often have abnormal paroxysmal motor activity, such as oral-buccal-lingual movements, pedaling, stepping, and rotatory arm …