Imaging in Pediatric Multiple Sclerosis : An Iconographic Review.

Abstract

Pediatric-onset multiple sclerosis (POMS) is defined by afirst multiple sclerosis (MS) attack occurring before 18years old and is diagnosed by demonstration of dissemination in time (DIT) and space (DIS). Although guidelines evolved over the years, they always recognized the importance of magnetic resonance imaging (MRI) for diagnosis. The 2017 McDonald criteria are increasingly used and have been validated in several cohorts. The use of MRI is the most important tool for the early diagnosis, monitoring, and assessment of treatment response of MS and standard protocols include precontrast and postcontrast T1, T2, fluid attenuation inversion recovery (FLAIR) and diffusion sequences. A distinctive MS lesion compromises white matter and it is well-demarcated and confluent, showing demyelination, inflammation, gliosis, and relative axonal preservation. Considering the growing recognition of pediatric MS as adifferential diagnosis for children presenting with aclinical central nervous system event, we present aPOMS lesions guide (periventricular, juxtacortical, infratentorial, spinal cord, cortical, tumefactive, black hole, contrast-enhanced). Owing to its rareness, POMS is a diagnosis by exclusion and MRI plays afundamental role in distinguishing POMS from other demyelinating and non-demyelinating conditions. Three main groups of disorders can mimic POMS: inflammatory, metabolic and tumoral; however, imaging patterns earlier described lower the possibilities of alternative diagnoses and strongly suggest POMS when likely.