Cerebral Palsy Research Network Blog

PVL

Periventricular leukomalacia (PVL) is a type of brain injury that affects premature infants. The condition involves the death of small areas of brain tissue around fluid-filled areas called ventricles. The damage creates “holes” in the brain. “Leuko” refers to the brain’s white matter. (1)

The classic brain injury of spastic diplegia is called periventricular leukomalacia (PVL). The following is an explanation of the terms:

➡ Periventricular: The ventricles are the black, kidney-shaped areas in figure 2.2.1. The injury (colored area) occurs near these ventricles, hence the term periventricular, which means around the ventricles.

➡ Leukomalacia: Leuko means white and malacia means abnormal softening of tissue. The term leukomalacia means softening of the white tissue. The white tissue in that area includes the communication tracts (corticospinal tracts) that connect the brain (cerebral cortex) and spinal cord. These communication tracts in the regions around the ventricles (periventricular) are involved in the control of movement and posture. The full term PVL thus means softening of the white tissue around the ventricles. PVL results in the motor problems we see in spastic diplegia. The communication tracts closest to the ventricles relate to the ankle, those next closest relate to the knee, and those next closest relate to the hip. We will see later that this mirrors the pattern of problems found in spastic diplegia: the ankle is more involved than the knee, which in turn is more involved than the hip. In addition, there is less upper limb involvement in spastic diplegia, and, as we can see in the diagram, those tracts are even further from the site of the injury. The injury is usually bilateral, i.e., affecting both sides of the brain but it can be uneven. How severe the spastic diplegia is depends on the amount of brain injury. (2)

(1) “Periventricular Leukomalacia: MedlinePlus Medical Encyclopedia.” MedlinePlus, U.S. National Library of Medicine, medlineplus.gov/ency/article/007232.htm.

(2) Collison L (2020) Spastic Diplegia–Bilateral Cerebral Palsy. St Paul: Gillette Children’s Specialty Press.