Search

• Negative central activity (NCA) is a frequent triphasic abnormal electroencephalographic feature of the extreme prematurity. • NCA is associated with severe intraventricular haemorrhage and may reflect the functional neural impact of vascular pathology. • The NCA association with adverse outcome argues for its consideration in brain function assessment and prognosis prediction. To characterize Negative Central Activity (NCA), an overlooked electroencephalographic activity of preterm newborns and investigate its relationship with brain injuries, dysfunction, and neurodevelopmental outcome. 109 preterm infants (23–28 weeks) were retrospectively included. NCA were selected at the negative peak on EEG. Individual averaged NCA were automatically characterized. Brain structural data were collected from cranial ultrasounds (cUS). The neurodevelopmental outcome at two years of age was assessed by the Denver Developmental Screening Test-II. Thirty-six (33%) children showed NCA: 6,721 NCA were selected, a median of 75 (interquartile range, 25/157.3) per EEG. NCA showed a triphasic morphology, with a mean amplitude and duration of the negative component of 24.6–40.0 µV and 222.7–257.3 ms. The presence of NCA on EEG was associated with higher intraventricular haemorrhage (IVH) grade on the first (P = 0.016) and worst neonatal cUS (P < 0.001) and poorer neurodevelopmental outcome (P < 0.001). NCA is an abnormal EEG feature of extremely preterm newborns that may correspond to the functional neural impact of a vascular pathology. The NCA relationships with an adverse outcome and the presence/severity of IVH argue for considering NCA in the assessment of pathological processes in the developing brain network and for early outcome prediction. [ABSTRACT FROM AUTHOR]

Aim: To determine the prognostic value of conventional electroencephalography (EEG) monitoring in neonatal hypoxic–ischemic encephalopathy (HIE). Method: In this multicentre retrospective study, 95 full‐term neonates (mean of 39.3wks gestational age [SD 1.4], 36 [38%] females, 59 [62%] males) with HIE (2013–2016) undergoing therapeutic hypothermia were divided between favourable or adverse outcomes. Background EEG activity (French classification scale: 0–1–2‐3‐4‐5) and epileptic seizure burden (epileptic seizure scale: 0–1‐2) were graded for seven 6‐hour periods. Conventional EEG monitoring was investigated by principal component analysis (PCA), with clustering methods to extract prognostic biomarkers of development at 2 years and infant death. Results: Eighty‐one per cent of infants with an adverse outcome had a French classification scale equal to or greater than 3 after H48 (100% at H6–12). The H6–12 epileptic seizure scale was equal to or greater than 1 for 39%, increased to 52% at H30–36 and then remained equal to or greater than 1 for 39% after H48. Forty‐five per cent of infants with a favourable outcome had a H6–12 French classification scale equal to or greater than 3, which dropped to 5% after H48; 13% had a H6–12 epileptic seizure scale equal to or greater than 1 but no seizures after H48. Clustering methods based on PCA showed the high efficiency (96%) of conventional EEG monitoring for outcome prediction and allowed the definition of three prognostic EEG biomarkers: H6–78 French classification scale mean, H6–78 French classification scale slope, and H30–78 epileptic seizure scale mean. Interpretation: Early lability and recovery of physiological features is prognostic of a favourable outcome. Seizure onset from the second day should also be considered to accurately predict neurodevelopment in HIE and support the importance of conventional EEG monitoring in HIE in infants cooled with therapeutic hypothermia. What this paper adds: Comprehensive analysis showed the high prognostic efficiency (96%) of conventional electroencephalography (EEG) monitoring.Prognostic EEG biomarkers consist of the grade of background EEG activity, its evolution, and the mean seizure burden.Persistent seizures (H48) without an improvement in background EEG activity were consistently associated with an adverse outcome. [ABSTRACT FROM AUTHOR]