Objectives: Numerous electroencephalographic studies have been carried out on positive rolandic sharp waves (PRSW) in neonates. An additional EEG abnormality noted in our institution is the presence of High Amplitude Positive Rolandic Sharp waves (HAPRS) which have not been described in the English literature. Our objectives were to characterize the HAPRS and differentiate them from PRSW and to ascertain whether there is a clinical correlation of HAPRS and their significance on neurological outcome of neonates.
Methods: A retrospective review was conducted of all neonatal patients who had standard neonatal EEG recordings performed in the Neonatal Intensive Care Unit (NICU) at The Hospital for Sick Children, Toronto, from January 2003 to December 2004. HAPRS were determined by their amplitude >200ìV, duration <400 mille seconds, their positive sharply contoured waveform and their maximal distribution over the mid-temporal area, all clearly distinguishable from the ongoing background activity and the PRSW.
Results: Three hundred and sixty six EEGs were analyzed. HAPRS were observed in 34 out of 253 infants (13%). Mean follow-up=13.4 months (range: 3 days to 32 months). Out of 34 infants with recorded HAPRS, 19 (56%) had abnormal neurological development, including global delay, language delay or death. Neonates with HAPRS with associated abnormal EEG background activity were found to have poor neurological outcome in 71%.
Conclusion: High Amplitude Positive Rolandic Sharp waves (HAPRS) appear to be a distinct neurophysiologic feature. HAPRS may be a unique EEG finding in neonatal recordings that may merit careful interpretation and description in EEG reports. This study provides additional insights into the prognostic value of neonatal EEG.
