PERIVENTRICULAR LEUKOMALACIAS - 1 - HISTO LOGICAL AND PATHOPHYSIOLOGICAL ASPECTS

The term 'periiventricular leukomalacia' (PVL) usually covers necrotic and/or gliotic lesions from perinatal origin occurring in the periven tricular ring of telencephalic white matter. PVLs are found post-morte m in one third of brains from autopsies of premature infants; PVLs are diagnosed in 4 to 10% of infants born before 33 weeks of gestation an d remaining alive more than 3 days after birth. PVL is very rare in at term infants. The proportion of PVLs from prenatal origin is estimate d between one third and one half of cases. Recent progresses in neuroe pidemiology, developmental neurobiology and imaging methods permit to revisit the pathophysiology of PVLs on a multifactorial basis. The fin al result of these multiple factors seem to be calcium influx due to g lutamatergic overactivation triggered by cytokines, infection and infl ammation, and deficit in neurotrophic factors. Periventricular topogra phy can be explained by properties of intracerebral vascular wail at t his stage of angiogenesis and by perfusion failure/hypoxia. (C) 1998, Elsevier, Paris.