Application of Diffusion Tensor Imaging to Better Understanding Pathogenesis of the Pelizaeus-Merzbacher Disease

Introduction: Diffusion tensor imaging (DTI) is a non-invasive exam that can characterize the microstructural properties of the brain white matter through the molecular diffusion processes. The application of DTI to the central nervous system (CNS) can accurately discriminates among different CNS disease pathologies by evaluating the microstructural architecture of the axonal fibers and myelin membrane in diverse groups of dysand demyelinating disorders. Pelizaeus-Merzbacher disease (PMD) is an X-linked disorder of the central nervous system (CNS), caused by a wide variety of mutations affecting proteolipid protein 1 (PLP1), the major protein in CNS myelin [1]. PLP1 is the major structural protein in CNS myelin, and is believed to form ‘adhesive struts’ that bind adjacent lamellae of myelin membrane in maintaining compaction of the myelin sheath [2]. The aim of this study was to quantify separately the water diffusivity components and directionality of major white-matter (WM) structures (figure 1). We hypothesize that patients with PMD experience severe dysmyelination of WM structures without axonal damages.