What is the most common type of neonatal seizure?

The most common type of neonatal seizure is subtle seizures. This form of seizure often involves subtle motor phenomena such as brief episodes of eye deviations, subtle twitching of facial muscles, or rhythmic movements of the extremities. These can sometimes be difficult to differentiate from normal newborn behaviors, which can lead to underdiagnosis.

Subtle seizures are particularly prevalent in preterm and term infants, especially those who may have suffered from hypoxic ischemic encephalopathy or other neurological insults. In contrast to the more overt manifestations of other seizure types, subtle seizures can present with a change in tone or posturing without clear convulsions. Recognition of these seizures is crucial for early intervention and management, which can significantly affect outcomes for the affected neonates.

Other types of seizures listed, such as tonic, clonic, and myoclonic seizures, are less frequent in the neonatal population. Tonic seizures can lead to rigid posturing, clonic seizures are characterized by rhythmic jerking movements, and myoclonic seizures involve sudden, brief muscle jerks—each presenting with more distinct clinical signs compared to subtle seizures. Thus, understanding the nature and presentation of subtle seizures is essential for proper assessment and treatment in neonatal care.