Etiologies and distribution of neonatal leukomalacia.

Neonatal leukomalacia was classified into 4 groups: focal (F), widespread (W), diffuse (D), and multicystic encephalomalacia (MCE) according to the distribution of ischemic necrosis in the cerebral hemisphere. The highest and lowest values of PaCO2, PaO2, and pH and the lowest systolic and diastolic blood pressures were compared among each group and controls. The lowest PaCO2 values were significantly lower in MCE than in the F, W, and D (F + W + D) group or controls. The lowest values of systolic and diastolic blood pressures in the W and F + W + D groups were significantly lower than in the controls; therefore, hypocarbia can be an etiologic factor of MCE rather than periventricular leukomalacia. Hypotension may be closely related to a causal factor of neonatal leukomalacia.