Positive rolandic sharp waves in preterm infants with periventricular leukomalacia: Their relation to background electroencephalographic abnormalities

The aim of this study was to clarify the significance of positive rolandic sharp waves (PRS) in preterm infants with periventricular leukomalacia (PVL ) and their relation to background electroencephalographic (EEG) abnormalit ies. We retrospectively evaluated EEC findings of 93 preterm infants; 31 in fants in the PVL group and 62 in the control group. PVL was diagnosed on th e basis of ultrasonographic findings. We evaluated the EEG within 3 weeks o f life in this study, PRS were defined as sharp transients of positive pola rity appearing in the rolandic regions with an amplitude of more than 100 m u V, sharply differentiated from the background activites. The number of PR S per minute was calculated over each record. PRS were defined as present w hen their frequency was beyond 0.1 per minute, PRS were observed in 14 (45% ) and disorganized patterns in 27 (87%) of 31 infants in the PVL group, but both were not recognized in any infants in the control group. PRS were alw ays associated with disorganized patterns. In the first EEC, PRS were absen t in 8 of 11 infants with more than two recordings, although at least one o f acute or chronic stage EEG abnormalities were already present. PRS were o bserved in 9 of 10 infants with severe diplegia, in 5 of 11 infants with mo derate diplegia and none in 10 infants with mild diplegia, The average age of the first appearance of PRS was 7.6 days. The average age of the first a ppearance of periventricular echodensity and cyst was 4.2 days and 21.1 day s, respectively. In conclusion, PRS are related to severe deep white matter injury and could be an early marker of severe PVL. PRS appeared in combina tion with disorganized patterns and were considered to be incorporated into chronic-stage EEG abnormalities. Detailed evaluation of background EEC act ivities can be helpful in detecting PVL with a high sensitivity from the ea rly neonatal period.