Abnormal periventricular white matter morphology Periventricular leukomalacia Periventricular leukomalacia is characterized by diffuse injury of deep cerebral white matter, accompanied in its most severe form by focal necrosis. The neuropathologic hallmarks of PVL are microglial activation and focal and diffuse periventricular depletion of premyelinating oligodendroglia. UMLS:C0023529 SNOMEDCT_US:230769007 Periventricular leukomalacia is the leading known cause of cerebral palsy. Magnetic resonance imaging-based neuroimaging techniques provide greater diagnostic sensitivity for PVL than does head ultrasonography and often document the involvement of telencephalic gray matter and long tracts in addition to periventricular white matter. HP:0006970 PVL