Specific Imaging Findings

The earliest imaging signs of periventricular leukomalacia (PVL) are periventricular hyperechogenicity on brain ultrasound scans, corresponding to areas of low ADC value on MRI. In the subacute stage, there is cystic cavitation of the most severely affected areas, typically the peritrigonal parietal white matter. These cystic areas tend to coalesce, and are eventually incorporated by the ventricular trigones, that become dilated, characteristically with wavy contours. Depending on the extent of parenchymal damage, variable degrees of peritrigonal white matter thinning and T2 hyperintensity, roughly symmetrical dilatation of the ventricular trigones, and calcarine cortex atrophy are present at later stages. The parenchymal damage can sometimes be associated with micro-hemorrhages, revealed in the chronic stage as hypointense dots in the periventricular areas or hypointense ependymal lining on T2*-weighted MR imaging. There is no intervening normal-appearing parenchyma between the trigonal walls and the periventricular injured white matter. Unilateral and/or frontal PVL is much less common.

Pertinent Clinical Information

Pre-term neonates can present with hemodynamic instability and partial asphyxia. The end result of the related brain insults is most commonly PVL. Term neonates with hypoperfusion or partial asphyxia present brain injuries in different locations due to different topography of watershed areas in the term brain, and different regional brain vulnerability. Patients with PVL are usually affected by variable severity of spastic paraparesis, as well as visual and cognitive impairment.