Late-onset circulatory dysfunction of premature infants and late-onset periventricular leukomalacia.

BACKGROUND: The sudden appearance of hypotension and oliguria without obvious cause following stable circulation and respiration in preterm infants is frequent in Japan. Such episodes are referred to as late-onset circulatory dysfunction of premature infants (LCD). Volume expanders and inotropic agents are often ineffective against this condition, whereas i.v. steroids are significantly effective. A major problem is that cystic periventricular leukomalacia (PVL) often develops a few weeks after an episode. The aim of the present study was to clarify the risk factors, including LCD, related to cystic PVL. METHODS: A case-control study was performed for preterm infants who were delivered at <33 weeks of gestation and admitted to seven neonatal intensive care units in Japan. Cystic PVL infants were stratified into early-onset PVL diagnosed within 28 days of age and late-onset PVL diagnosed after more than 28 days of age. The reported and new risk factors for PVL, for each group of PVL infants, and for all PVL infants, were compared with controls. RESULTS: Thirty-two infants were diagnosed with cystic PVL (17 early-onset and 15 late-onset). All PVL infants significantly differed from controls on Apgar score, number of abortions and pregnancies, intraventricular hemorrhage, and LCD. LCD was diagnosed in 28.1% of both PVL groups compared with 6.3% of controls (P = 0.02). Multivariate analysis demonstrated significant association between late-onset PVL and LCD. CONCLUSION: LCD was significantly associated with cystic PVL, especially late-onset PVL. Elucidating the cause of LCD might reduce the incidence of PVL and improve the neurological prognosis of preterm infants.

Periventricular leukomalacia with late-onset circulatory dysfunction of premature infants: correlation with severity of magnetic resonance imaging findings and neurological outcomes.

The incidence of late-onset circulatory dysfunction (LCD) of premature infants, which is characterized by sudden hypotension and oliguria, has recently increased in Japan. This condition suddenly occurs after several days of age without obvious causes in preterm infants with stable respiration and circulation. Intravenous steroids frequently improve the hypotension. The main problem with LCD is the subsequent and frequent onset of periventricular leukomalacia (PVL), and neurological development appears to be worse in PVL patients with LCD than those without LCD. The aim of this study was to determine whether the severity of magnetic resonance imaging (MRI) findings and neurological outcomes differ between infants who developed PVL after LCD and those who developed PVL without LCD. We retrospectively studied preterm infants who were delivered at less than 33 weeks of gestation between the years 2000 and 2003. During the study period, 10 and 26 infants developed PVL with and without LCD, respectively. The incidence of severe or moderate MRI findings was significantly higher in PVL patients with LCD (100%) than those without LCD (50%; p < 0.05). The incidence of severe cerebral palsy was 88% in PVL infants with LCD and 43% in PVL infants without LCD (p < 0.05). Moreover, the incidence of visual disorders was significantly higher in PVL infants with LCD (63%) than those without LCD (9%; p < 0.01). In conclusion, neurological outcomes are worse in preterm infants who develop PVL with LCD than those without LCD, which is well correlated to the severity judged by MRI findings.