Abstract
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 electroencephaiographic (EEG) abnormalities. We retrospectively evaluated
EEG findings of 93 preterm infants; 31 infants in the PVL group and 62 in the control
group. PVL was diagnosed on the basis of ultrasonographic findings. We evaluated the
EEG within 3 weeks of life in this study. PRS were defined as sharp transients of
positive polarity appearing in the rolandic regions with an amplitude of more than
100 μV, sharply differentiated from the background activites. The number of PRS per
minute was calculated over each record. PRS were defined as present when 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 always associated with disorganized patterns. In the
first EEG, PRS were absent in 8 of 11 infants with more than two recordings, although
at least one of acute or chronic stage EEG abnormalities were already present. PRS
were observed in 9 of 10 infants with severe diplegia, in 5 of 11 infants with moderate
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 appearance of periventricular echodensity
and cyst was 4.2 days and 21.1 days, respectively. In conclusion, PRS are related
to severe deep white matter injury and could be an early marker of severe PVL. PRS
appeared in combination with disorganized patterns and were considered to be incorporated
into chronic-stage EEG abnormalities. Detailed evaluation of background EEG activities
can be helpful in detecting PVL with a high sensitivity from the early neonatal period.
Key words
Periventricular leukomalacia - Positive rolandic sharp waves - Acute-stage EEG abnormalities
- Chronic-stage EEG abnormalities
