Long-term clinical outcome of neonatal EEG findings.

The aim of the study is to determine how specific EEG findings during neonatal period correlate with clinical outcome on follow-up. This is a retrospective study of 118 term newborns who had EEG in the first month of life and subsequent clinical assessment between 4 and 16 years. Clinical neurologic outcome was classified into "favorable" when patients had no or only mild limitation in assessment, "unfavorable" when patients had moderate to severe abnormalities in assessment, and "epilepsy" when patients had seizures. Of the 118 neonates, 36 (30.5%) had favorable and 82 (69.5%) had unfavorable outcome; 89 (75.4%) had epilepsy and 28 (23.7%) had not. Sixty-seven (57%) had abnormal EEG background of which 56 had both unfavorable outcome and epilepsy; 102 (86%) had sharp transient discharges of which 75 had unfavorable outcome; 20 (17%) had ictal epileptiform discharges of which 18 had unfavorable outcome; 98 (83%) had abnormal overall EEG impression of which 77 had unfavorable outcome and 80 had epilepsy. Abnormal EEG background (particularly suppression) during neonatal period may be predictive of Unfavorable outcome. Overall impression of EEG may be predictive of clinical outcome, even when individual parameters were not predictive. Other findings did not appear to be predictive.