Amplitude-Integrated EEG Pattern Predicts Further Outcome in Preterm Infants

Abstract

Changes in EEG background activity are powerful but nonspecific markers of brain dysfunction. Early EEG and amplitudeintegrated EEG (aEEG) pattern predict further neurodevelopmental outcome in term infants; however, sufficient data for prognostic value of aEEG in preterm infants are not available so far. The aim of the study was to evaluate whether aEEG predicts further outcome and to compare it to cerebral ultrasound assessment. In 143 preterm infants, aEEG within the first 2 wk of life and outcome data at 3 y of age (Bayley Scales) could be obtained .aEEG was classified into a graded score according to background activity, appearance of sleep-wake cycling, and occurrence of seizure activity. In preterm infants, aEEG was significantly associated with further outcome. Specificity was 73% for assessment within the first and increased to 95% in the second week of life, whereas sensitivity stayed nearly the same 87% (first week) to 83% (second week). Cerebral ultrasound showed a specificity of 86% within the first and second week, sensitivity also stayed nearly the same (74 and 75%). aEEG has a predictive value for later outcome in preterm infants and can be used as an early prognostic tool. D espite recent advances in perinatal care, the incidence of impaired outcome in preterm infants has not decreased. Rates of CP and overt cerebral lesions [e.g. cystic leukomalacia and intraventricular hemorrhage (IVH)] are decreasing, but the incidence of neurodevelopmental impairment stays high in preterm infants. This is due to different mechanisms in brain injury (e.g. inflammation, oxidative stress, impaired connectivity) and result in mainly cognitive impairment (1-3). Extensive studies have demonstrated the usefulness of cerebral ultrasound (CUS) in detecting cerebral lesions and predicting neurological outcome (4 -7). Also conventional EEG is proven to be useful in evaluating brain function and in predicting further development (8). On the background of an acute brain insult, EEG activity shows various degrees of depression and its severity parallels the magnitude of the brain lesion. These "acute-stage" abnormalities gradually improve with time and are replaced by "chronic-stage" abnormalities such as dysmaturity and disorganization. Several studies suggest that acute changes in the EEG background are powerful but nonspecific markers of brain dysfunction (8,9). In addition, a correlation between chronic-stage abnormalities and cognitive impairment is suggested (10 -13). Although early postnatal EEG has been used increasingly in preterm infants during the last years, there is no clear evidence to confirm its prognostic value in preterm infants of Ͻ30 wk GA (9).The most dominant feature of the extremely preterm infants' EEG is discontinuity, making a "grading" and "severityscoring" in terms of depression in these infants difficult. Furthermore validated reference criteria with regard to maturation and appearance of sleep-wake cycling (SWC) to score "disorganization" and/or "dysmaturity" are still scarce.Recordi...

Predicting 2-y outcome in preterm infants using early multimodal physiological monitoring

“…Tyson et al (11) demonstrated that a five-factor model which consists of GA, BW, gender, exposure to antenatal corticosteroids, and singleton vs. twin birth, performed better than GA alone for the prediction of outcome in a cohort of preterm infants between 22-25 wk GA. Our AUC results showed an improvement from both these two predictive models (10,11). Also for our study, the sensitivity, specificity, and OR values showed similar values or improvements to previous studies in which EEG or aEEG was evaluated as one predictor or the only predictor (13,15,16). However, studies that examined serial EEG recordings or used Articles a larger cohort size had better sensitivity or specificity values (12,14).…”

“…Other studies have shown that the amplitude integrated EEG (aEEG) can predict long-term outcome, with specificity ranging from 73 to 89% and sensitivity ranging from 56 to 87% (15)(16)(17). To date, however, no standardized method for the accurate prediction of long-term outcome in very preterm infants has been successfully translated into clinical practice.…”

Delayed Cyclic Activity Development on Early Amplitude-Integrated EEG in the Preterm Infant with Brain Lesions

“…The interpretation of aEEG tracings in preterm infants, however, is different from that in term newborns. Several studies focused on defining normal aEEG tracing [3][4][5][6][7] and its prognostic value [8] in preterm newborns. In fact, in the preterm newborn the predominant aEEG background pattern is discontinuous [3] ; the aEEG trace evolution early after birth is influenced by the time of extrauterine exposure [4][5][6] , and the cyclical character is less defined than in term newborns [2,6,7] .…”

Impact of perinatal factors on continuous early monitoring of brain electrocortical activity in very preterm newborns by amplitude-integrated EEG

“…In term infants with perinatal hypoxic-ischemic encephalopathy, aEEG background pattern characteristics and changes in cycling activity provide prognostic information on neurodevelopmental outcome (3). Recent studies demonstrated that early aEEG pattern can predict both short-and long-term outcome in the preterm (4,5). Normal aEEG background pattern in preterm infants (6) differs, however, from that in the term infants (7), and interpretation of its tracing is problematic because it is strongly influenced by brain maturation (6,7).…”