Neonatal seizures: Aetiology, management and prognosis

Abstract

Seizures remain a significant issue in the newborn period because they represent the most distinctive sign of neurological disorder. A seizure is a transient alteration in neurologic function involving motor activity, changes in level of alertness and impairment in autonomic function. It follows a paroxysmal discharge of a population of neurons that may spread and activate other brain structures. These electrical discharges are repetitive with a gradual build-up and termination and present a characteristic pattern of evolution lasting at least several seconds. The clinical expression of convulsions in newborn infants is often fragmentary, variable, subtle and not well organized because the neonatal brain is not well interconnected. A particular problem is the recognition of neonatal seizures particularly in the premature infant as well as determination of their aetiology. The precise overall incidence of neonatal seizures is difficult to estimate. It has been reported that 0.2-1.4% of all newborns have recognized convulsive phenomena? Sick preterm infants present a higher incidence which has been reported to be 20-25% but this has decreased in recent years reflecting a reduced number of massive intracranial lesions in babies receiving intensive care? The outcome of neonates with seizures varies considerably with the aetiology. Mortality ranges from 15% to 40% but it can reach 80-90% when populations of preterm infants with brain damage are considered. 3 Many questions about diagnosis, biochemical effects, mechanisms of brain injury and the adequacy of treatment remain unresolved.