In the presence of diffuse bilateral rather symmetrical white matter signal abnormalities with thickened cerebral cortex suggestive of cortical malformation (pachygyria)  and numerous dilated perivascular spaces in a child, mucopolysaccharidosis has to be considered as a primary differential diagnosis among metabolic disorders. 

In this instance, a diagnosis of mucopolysaccharidosis type I has been made after lab and genetic workup.