Behavior and EEG concordance of active and quiet sleep in preterm very low birth weight and full-term neonates at matched conceptional age Aline Ávila dos Santos d , Richard Lester Khan a , Gibsi Rocha f , Magda Lahorgue Nunes b,c,e, ⁎ a Pediatric Neurologist - ULBRA, Brazil b Laboratory of Clinical Neurophysiology, Hospital São Lucas, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Brazil c Brain Institute (INSCER), Brazil d Division of Child Psychiatry - Hospital São Lucas PUCRS, Brazil e Department of Neurology PUCRS School of Medicine, Brazil f Department of Psychiatry PUCRS School of Medicine, Brazil abstract article info Article history: Received 7 January 2014 Received in revised form 18 June 2014 Accepted 30 June 2014 Available online xxxx Keywords: Preterm infants Behavior Prechtl scale Sleep Neonatal EEG Background: Sleep organization in neonates is an established predictor of neurological outcome and can be eval- uated through the concordance between EEG and behavioral parameters. Aims: To evaluate the correlation between sleep stages and behavioral states in neonates. Study design: Longitudinal study performed in a birth-cohort of preterm low birth weight neonates. Subjects: Twenty five neonates, 15 preterm (gestational age between 27 and 33 weeks) and low birth weight (800–1500 g) and 10 full-term neonates that served as controls. Measures: All neonates were submitted to video-electroencephalography of, at least, 60 minute duration. The preterm during the first 15 days of life and, subsequently, at 38–42 weeks of conceptional age. The full-term be- tween the 1st and 2nd days of life. The characterization of sleep stages by EEG parameters and behavioral states (based on Prechtl scale) was performed independently by previously trained researchers. Results: Active sleep (AS) was the predominant sleep stage in the three groups. Preterm neonates had an increase in concordance between state 1 and quiet sleep (QS) from the 1st to the 2nd EEG (p b 0.001), however in both observations it remained inferior when compared to state 2 and AS (p b 0.001). Concordance between AS and state 2 was similar (p = 0.567). Conclusions: Concordance between EEG and behavior is lower in QS in preterm and full-term neonates when compared to AS. Extra-uterine development of preterm neonates seems to accelerate concordance in QS. Prechtl behavior scale proved to be useful in preterm as percentage of concordance was similar in AS in the groups studied. © 2014 Elsevier Ltd. All rights reserved. 1. Introduction Children born preterm have a higher risk of developing a variety of neurodevelopmental disorders such as cerebral palsy, cognitive deficits, behavioral–social problems and language delay among others [1–5]. Previous follow-up studies of infants born preterm emphasize a direct relationship between birth weight, gestational age and future outcomes, whereby lower birth weight and gestational age are asso- ciated with more unfavorable outcomes [5]. However, the nature of the cerebral abnormality underlying these adverse neurologic out- comes is poorly understood. Intraventricular hemorrhage and focal periventricular leukomalacia were both viewed as the major forms of brain injury accounting for handicap after preterm birth. However, more recent studies suggest that diffuse white matter injury (diffuse periventricular leukomalacia) is also a major cause of neurodevelop- mental delay. Neuroimage studies have shown that reduction of gray matter volume may be involved [6–8]. Sleep is the main behavior state during the neonatal period and is an important marker of neurological development in preterm neonates [1]. Sleep and wakefulness states are well defined, in the neonatal period, based on physiological and behavioral variables which occur in particu- lar moments in a 24 hour period. Stable periods of active (REM) and quiet (NREM) sleep of more than 3 min duration have been document- ed by previous researchers from 27 to 28 weeks of gestational age [9–13]. Roffwarg and colleagues [14] were first to propose that the pri- mary function of active sleep (REM) was to act as an inductor of CNS de- velopment either in the fetus or the neonate. That is why the reduction Early Human Development 90 (2014) 507–510 ⁎ Corresponding author at: Brain Institute (INSCER), Av. Ipiranga 6690, 90610-000 Porto Alegre, RS, Brazil. Tel./fax: +55 5133847171. E-mail address: nunes@pucrs.br (M.L. Nunes). http://dx.doi.org/10.1016/j.earlhumdev.2014.06.014 0378-3782/© 2014 Elsevier Ltd. All rights reserved. Contents lists available at ScienceDirect Early Human Development journal homepage: www.elsevier.com/locate/earlhumdev