The dysmature EEG pattern in infants with bronchopulmonary dysplasia and its prognostic implications

Abstract

Bronchopulmonary dysplasia (BPD) is a chronic lung disease which occurs in premature infants who require prolonged mechanical ventilation and supplemental oxygen support. Infants with severe BPD often have neurological sequelae or early mortality. We have observed a pattern of delay in the maturation of cerebral electrical activity of some infants who have more severe forms of BPD. This delayed electroencephalographic (EEG) maturation or ‘dysmaturity’ is best recognized when the conceptional age (CA) of the premature infant approaches term and is characterized by the presence of EEG activity which normally disappears in premature infants by 36–37 weeks CA. We studied 36 infants with BPD who had serial EEGs and at least 1 EEG between 37 and 42 weeks CA. Dysmature EEGs were found in 23 infants. Unfavorable outcomes were found in 83% (19/23) of these infants, including 22% (5/23) mortality, and 61% (14/23) abnormal or suspect neurological outcome. Thirteen infants had EEGs which lacked dysmature features. Of these infants, 62% (8/13) had normal neurological outcome, and 38% (5/13) had unfavorable outcome (1 death, 2 abnormal, and 2 suspect). In 2 of the 5 infants with unfavorable outcomes without dysmature EEGs, a suppression-burst pattern (known to be associated with neurological sequelae) was found. The presence of dysmature patterns in the near-term or term EEG was associated with significantly less favorable outcome ( P = 0.01). Several other clinical factors which were associated with dysmature EEGs are also discussed.