Neonatal seizures occur frequently in fullterm and preterm infants, particularly in those suffering from pre-, peri-, or neonatal problems affecting the developing brain, e.g. hypoxic-ischemic encephalopathy, metabolic disorders, infectious diseases, and cerebral malformations, especially migrational disorders resulting in various types of cortical dysgenesis. Neonatal seizures without underlying diseases may occur as benign (often familial) neonatal seizures which are due to genetically determined defects of ion channels, predominantly the potassium channel.
Neonatal seizures are challenging for both neonatologists and pediatric neurologists in respect to a) diagnostic work-up, b) adequate treatment, and c) prognostic implications.
Due to the immature brain, seizures in newborns are less well organized and thus may occur as tonic, clonic, myoclonic uni- or bilateral, multifocal and migrating events. Seizures may appear as pedalling movements, convulsive apnoea or mimic age-related physiologic episodes of sleep myoclonus or facial grimassing reminding of behaviours characteristic of active sleep.
Knowledge of the full clinical context helps to differentiate pathologic from physiologic events. The majority of neonatal seizures seem to occur as clinically subtle or even silent seizures detectable only by means of EEG recordings. According to recent studies electrical seizures do like clinical ones (+ or – EEG signature) indicate underlying disorders and impair brain functions. Thus, early and continuous detection of all types of seizures is crucial for diagnosis and treatment of underlying problems and treatment of seizures which are damaging the developing brain in addition. Since antiepileptic drugs have deleterious effects on animal brains (Wasterlain et al., Bittigau et al.) it is crucial to avoid both overtreatment and underrecognition of seizures and thus prompt diagnosis and treatment of underlying diseases. Prognosis of newborns with seizures primarily depends on nature and extent of underlying disorders but may be worsened by ongoing seizure activity.
