The impact of extrauterine life on visual maturation in extremely preterm born infants.

BACKGROUND: Extrauterine life is an important factor when considering brain maturation. Few studies have investigated the development of visual evoked potentials (VEP) in extremely preterm infants, and only a minority have taken into consideration the impact of extrauterine life. The aim of this study was to assess the normal maturation of VEP in infants born prior to 29 weeks gestational age (GA) and to explore the potential influence of extrauterine life. METHODS: VEP were prospectively recorded in extremely preterm infants, and principal peaks (N0, N1, P1, N2, P2, N3) were identified. The mean of peak-time and percentages of peak appearances were assessed for three GA groups (23/24, 25/26, 27/28 weeks) and four subgroups of increasing postnatal age (PNA), up to 8 weeks after birth. RESULTS: A total of 163 VEP recordings in 38 preterm infants were analyzed. With increasing GA at birth, peak-times decreased. When comparing infants with equal GA but longer extrauterine life, those with the highest PNA demonstrated the shortest VEP peak-times. However, this effect was less present in infants born prior to 25 weeks GA. CONCLUSION: Provided that a certain maturational threshold is reached, extrauterine life appears to accelerate maturation of the visual system in preterm infants.

Amplitude-integrated electroencephalography shows that doxapram influences the brain activity of preterm infants.

AIM: The aim of this study was to measure the brain activity of preterm infants treated with caffeine citrate and doxapram for preterm apnoea, using amplitude-integrated electroencephalography (aEEG), to identify any adverse effects on cerebral function. METHODS: We analysed the aEEG tracings of 13 preterm infants <30 weeks of gestation before, during and after doxapram treatment, with regard to background activity (percentages of continuous and discontinuous patterns), occurrence of sleep-wake cycling and appearance of electrographic seizure activity. They were also compared with 61 controls without doxapram treatment. RESULTS: During doxapram treatment, aEEG tracings showed an increase in continuous background activity (19 ± 30% before treatment, 38 ± 35% during treatment) and a decrease in discontinuous patterns. In addition, they showed more frequent electrographic seizure activity (0% before treatment, 15 ± 37% during treatment) and less frequent sleep-wake cycling (92 ± 27% before treatment, 85 ± 37% during treatment) could be observed. These results were confirmed when compared to the control group. CONCLUSION: Doxapram treatment influences aEEG in preterm infants, showing higher percentages of continuous activity as well as more electrographic seizure activity and less sleep-wake cycling. It should, therefore, be used with caution in very preterm infants.

Being Born Small for Gestational Age Influences Amplitude-Integrated Electroencephalography and Later Outcome in Preterm Infants.

BACKGROUND: The impact of growth restriction on perinatal morbidity is well known, but electroencephalographic (EEG) data on its influence are still scarce. OBJECTIVES: We aimed to analyze the influence of being born small for gestational age (SGA; defined as a birth weight <10th percentile) on the amplitude-integrated EEG (aEEG) score in the first 2 weeks of life in preterm infants born before 30 weeks of gestation, and its impact on later outcome. METHODS: aEEG data obtained within the first 2 weeks of life on preterm infants born SGA and before 30 weeks of gestational age (GA) were analyzed retrospectively using a combined score [including background activity, occurrence of sleep-wake cycles (SWC) and suspected seizure activity]. Neurodevelopmental outcome was evaluated at 24 months by means of the Bayley Scales of Infant Development II and a standardized neurological examination. RESULTS: One hundred and thirty-six patients were included (47 SGA and 89 controls). Infants with SGA had abnormal aEEG scores significantly more often (57 vs. 24%, p = 0.002) than infants born appropriate for gestational age (AGA). They also displayed SWC less frequently (65 vs. 96%, p = 0.001), were more likely to develop seizure activity (15 vs. 4%, p = 0.013) and had a normal neurodevelopmental outcome at the age of 2 years less frequently (36.2 vs. 59.6%, p = 0.02). CONCLUSION: Preterm infants born SGA and before 30 weeks of GA had less optimal scores on early aEEG and a poorer neurodevelopmental outcome at 24 months than the AGA controls.