Periventricular Leukomalacia

Periventricular Leukomalacia

Periventricular leukomalacia (PVL) is a form of white-matter brain injury, characterized by the necrosis (more often coagulation) of white matter near the lateral ventricles. It can affect newborns and (less commonly) fetuses; premature infants are at the greatest risk of the disorder. Affected individuals generally exhibit motor control problems or other developmental delays, and they often develop cerebral palsy or epilepsy later in life. This pathology of the brain was described under various names ("encephalodystrophy", "ischemic necrosis," "periventricular infarction", "coagulation necrosis", "leukomalacia," "softening of the brain," "infarct periventricular white matter", "necrosis of white matter", "diffuse symmetrical periventricular leukoencephalopathy"), and more often by German scientists, but the worldwide dissemination was the term «periventricular leukomalacia», introduced in 1962 B.A.Banker and J.C.Larroche. The term is not clear, since there are no softening of PVL, and more dense than surrounding areas of the brain foci of coagulation necrosis. V.V. Vlasyuk and V.P. Tumanov in 1985 published the world's first monograph devoted to PVL. The most comprehensive study of PVL in the world at the largest section material held V.V. Vlasyuk (1981) (frequency, etiopathogenesis, topography, degree of damage different parts of the brain, developmental stage lesions, histoneurology, the role of microglia, electron microscopy, histochemistry, and others), who first revealed the high incidence of optic radiation lesions and demonstrated that PVL - a persistent process that the old necrosis can join a new, foci of PVL may be at different stages of development. In the process of morphogenesis focuses PVL pass through three stages: 1) necrosis, 2) resorption, and 3) the formation gliosis scars or cysts. Cysts occur when large and confluent focuses of PVL, with mixed necrosis (kollikvacia in the center and coagulation rim at the periphery). Around the foci is generally defined area of other lesions of the brain white matter - the death of prooligodendrocytes, proliferation mikrogliocytes and astrocytes, swelling, bleeding, loss of capillaries, and others (the so-called "diffuse component PVL"). However, diffuse lesions without necrosis are not PVL.