The study included analysis of longitudinal recordings of amplitude-integrated EEG (aEEG) tracings on a weekly basis in preterm infants and evaluation of their neurodevelopmental outcome at the age of three years.

Aim of the study was to observe if there is a correlation of the aEEG tracings of the first weeks of life to later neurodevelopmental outcome and to evaluate if aEEG can be used as prognostic tool.

From the first week of life on aEEG-recordings were obtained on a weekly basis and the results of the first eight weeks of life were analyzed for this study.

aEEG-tracings were analyzed with regard to background activity (percentages of continuous and discontinuous patterns), the presence/absence of sleep-wake-cycles and the occurrence of seizure activity. These items where summed up in a score including three grades (normal, moderately and severely abnormal).

The aEEG was recorded as a single channel EEG from biparietal surface disk electrodes using a CFM (CFM 5330, Lectromed Devices Ltd., UK) or the CFM 6000 (Olympic Medical, USA). Assessment of neurodevelopmental outcome was done at three years of age by assessment of the Bayley Scales of Infant Development II (BSID-II) During the study period from January 1st 2000, and December 31st 2002 a total of 284 preterm infants less than 30 weeks´ gestational age were admitted to the neonatal intensive care unit of the Medical University of Vienna. Neurodevelopmental outcome could be obtained in 148/284 infants at the age of three years and these infants therefore fulfilled the inclusion criteria for this study

Inclusion Criteria:

• gestational age < 30 weeks

Exclusion Criteria:

• brain malformation
• inborn error of metabolism

inclusion of all preterm infants born below 30 weeks gestational age within the study period at medical university vienna