PURPOSE: Periventricular leukomalacia(PVL) is associated with the characteristic neurologic sequale of spastic diplegia or quadriplegia, and cortical blindness. So early diagnosis of PVL in the neonatal period is of importance because of the prognostic implications of this lesion. Novotny et al reported that Positive Rolandic Sharp waves(PRS) on the EEGs was a marker of PVL because most infants who had excessive PRS on their EEGs also had PVL on their neurosonography. PRS were present in most neonates at a time when neurosonography showed periventricular echodense lesions, prior to the appearance of cystic PVL. Therefore, the appearance of excessive PRS on the EEG is very useful for the early detection of PVL. The aim of this study is to assess the relationship between the PVL and PRS on the EEGs, to observe the appearance timing of PRS on the EEGs, and to evaluate the risk factors of later neurologic sequale. METHODS: Among the neonates admitted to the Sowha Childern's Hospital between 1989 and June 1993, 25 neonates with cystic PVL on neurosonography or CTscan were the study group. Control group were the age-matched 20 neonates who were admitted at the same time of study period. We reviewed the neurosonographic findings, EEG features, and charts retrospectively. RESULTS: 1) Excessive PRS were observed in 20 cases of study group(80%), whereas 1 case in control group(5%)(p<0.001). 2) The frequency of PRS was not affected by the abnormality of EEG background activity. 3) The frequency of PRS in a 10 minutes epoch was 14.5+11.1 in the study group, whereas 1.57+1.96 in the control group(p<0.001). 4) In most neonates, PRS were present at a time when the neurosonography showed periventricular echodense lesion or cystic PVL. 5) In a follow-up neurosonography, 12 among 17 neonates with localized PVL were normalized and only 5 cases had ventriculomegaly. Whereas, all of 5 extensive PVL had the sequale of ventriculomegaly or cerebral atrophy. 6) In a follow-up neurologic examination, the poorer sequale including spastic diplegia or quadriplegia was associated with the larger, the more extensive, and the subcortical PVL. CONCLUSIONS: 1) Excessive PRS were significantly more observed in the study group than in the control group(p<0.001). 2) The frequency of PRS was not affected by the abnormality of EEG background activity. 3) The prognosis of the neonates with PVL was depended on the size, extent, and location of the PVL rather than the presence or frequency of PRS.