NEURORADIOLOGYI n vanishing white matter (VWM), a form of leukodystrophy, the cerebral white matter is the only or the most prominently affected tissue (1). The MRI feature defining VWM is progressive rarefaction and cystic decay of the cerebral white matter, leading to a white matter signal close to or the same as that of cerebrospinal fluid (CSF) on proton density and fluid-attenuated inversion recovery (FLAIR) images (1). The rarefied and cystic white matter typically contains radiating stripes, suggesting relatively preserved perivascular tissue strands (1). The white matter involvement is extensive or diffuse (1); only the directly subcortical white matter may be spared (2). Neuropathologic evaluation confirms the interpretation of the MRI findings (3).VWM is caused by biallelic sequence variations in any of the EIF2B1-5 genes, which encode the five subunits of the eukaryotic translation initiation factor eIF2B (4,5). The onset of VWM is mainly in early childhood but ranges from the antenatal period to senescence (6). For onset before age 4 years, earlier manifestation is associated with faster clinical disease progression. Patients with onset after age 4 years tend to have a milder disease course, irrespective of the exact age at onset (6).Currently, there is no therapy for VWM, but various drugs are in clinical development and will be assessed in trials (7-9). Although clinical parameters provide primary outcome measures, MRI parameters may serve as secondary or surrogate outcome measures. For the past 3 decades, MRI has played an important role in the diagnosis of VWM (1). The time course of the cerebral white matter decay has, however, not been investigated, and systematic information on MRI evolution for different ages of onset is lacking. For MRI to play a role in therapeutic trials, this basic information is needed. We therefore studied the progression of cerebral white matter abnormalities at MRI in a large group of patients with genetically confirmed VWM, representing all ages of onset.Background: In vanishing white matter (VWM), a form of leukodystrophy, earlier onset is associated with faster clinical progression. MRI typically shows rarefaction and cystic destruction of the cerebral white matter. Information on the evolution of VWM according to age at onset is lacking.Purpose: To determine whether nature and progression of cerebral white matter abnormalities in VWM differ according to age at onset.
Materials and Methods:Patients with genetically confirmed VWM were stratified into six groups according to age at onset: younger than 1 year, 1 year to younger than 2 years, 2 years to younger than 4 years, 4 years to younger than 8 years, 8 years to younger than 18 years, and 18 years or older. With institutional review board approval, all available MRI scans obtained between 1985 and 2019 were retrospectively analyzed with three methods: (a) ratio of the width of the lateral ventricles over the skull (ventricle-to-skull ratio [VSR]) was measured to estimate brain atrophy; (b) cerebral white matter wa...