Electro-Clinical Correlations of Positive and Negative Sharp Waves on the Temporal and Central Areas in Premature Infants

Abstract

The goal of this study on 199 premature infants (24-41 weeks CA) was to investigate the electro-clinical correlations of positive and negative sharp waves, comparing those from the temporal and central areas. Positive discharges were seen more often less than 30 weeks CA and the negative type greater than 30 weeks. Patients without sharp waves rarely have seizures and those with paroxysms often do, dependent in part on the number of these discharges. When negative sharp waves are found on the frontal or occipital areas, where they uncommonly occur, the incidence of seizure almost doubles, compared to those on the central or temporal areas. Periventricular leukomalacia (PVL) was seen in less than one fourth of all patients, increasing to 32% with negative sharp waves, but nearly doubling the latter incidence with positive paroxysms, seen especially on the temporal, rather than central areas. Positive discharges were seen much more frequently with stage III-IV hemorrhage (Hg) than in stage I-II and these were mainly temporal, not central in location. Seizures and Hg were related only with grade III-IV, not with grade I-II Hg. Based on these data, positive sharp waves would predict in 69% of these infants the presence of at least one of the triad of seizures, intracerebral Hg or PVL, similar for the temporal and central locations. Follow-up studies showed that normal records at 30 weeks often changed to abnormal ones around 36 weeks. Finally, sensitivity data showed that for the positive sharp wave the highest values were for PVL, the lowest for seizures and midway for Hg, while the negative sharp waves show exactly the opposite, highest for seizures and lowest for PVL.