Cognitive outcome at 5 years in very premature children without severe early cerebral abnormalities. Relationships with EEG at 6 weeks after birth

Abstract

Aims of the study: This prospective study aimed to analyze the relationship between EEG at 6 weeks after birth and cognitive outcome at the age of 5 in children born very preterm who did not present with severe neonatal cerebral abnormalities.

Patients and methods: EEGs were recorded at 6 weeks of age in infants born <29 weeks of gestation or weighing <1000 g at birth. At 5 years, study participants underwent a neurological assessment and cognitive evaluation with the Kaufman Assessment Battery for Children (K-ABC).

Results: Fifty-eight children had an EEG at 6 weeks after birth. Fifty-one were evaluated at 5 years. Twenty-six children (51.0%) had one or more disabilities: neuromotor, sensory, behavioral, and/or cognitive. Children with EEG abnormalities had significantly more disabilities (20 of 25, 80%) than children with normal EEG (6 of 26, 23%) (P=0.0002). Thirty-five children underwent complete K-ABC assessment. Multiple linear regression analysis indicated a significant relationship between the overall EEG abnormalities (normal, dysmature, and/or disorganized) and two scales: mental processing composite (MPC) scales (P=0.0121), and sequential processing scales (P=0.0012). Dysmature EEGs were more predictive of lower MPC and sequential processing scales than disorganized EEGs. Immature occipital slow waves (i.e., too high for conceptional age) were consistently recorded in children with dysmature EEGs and associated with the lowest K-ABC scores.

Conclusion: EEG abnormalities recorded at 6 weeks after birth, such as immature occipital slow waves, were associated with later cognitive impairments. EEG at 6 weeks can be an early and reliable tool for assessing the risk of future cognitive impairment.

Keywords: Anomalies EEG au stade chronique; Chronic-stage EEG abnormalities; Cognitive disabilities; Disorganized EEG patterns; Dysmature EEG patterns; EEG dysmature; EEG désorganisé; Prognosis; Pronostic; Séquelles cognitives; Très grand prématuré; Very premature neonate.