REVIEW Pediatric multiple sclerosis: from clinical basis to imaging spectrum and differential diagnosis Igor G. Padilha 1,2 & Ana P. A. Fonseca 1,2 & Ana L. M. Pettengill 1,2 & Diego C. Fragoso 1,3 & Felipe T. Pacheco 1,2 & Renato H. Nunes 1,2 & Antonio C. M. Maia Jr 1,3 & Antônio J. da Rocha 1,2 Received: 6 July 2019 /Revised: 4 November 2019 /Accepted: 19 November 2019 # Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract Pediatric multiple sclerosis (MS) deserves special attention because of its impact on cognitive function and development. Although knowledge regarding pediatric MS has rapidly increased, understanding the peculiarities of this population remains crucial for disease management. There is limited expertise about the efficacy and safety of current disease- modifying agents. Although pathophysiology is not entirely understood, some risk factors and immunological features have been described and are discussed herein. While the revised International Pediatric MS Study Group diagnostic criteria have improved the accuracy of diagnosis, the recently revised McDonald criteria also offer some new insights into the pediatric population. It is fundamental that radiologists have strong knowledge about the vast spectrum of demyelinating disorders that can occur in childhood to ensure appropriate diagnosis and provide early treatment. Keywords Brain . Central nervous system . Children . Demyelination . Diagnostic criteria . Differential diagnosis . Magnetic resonance imaging . Multiple sclerosis . Spinal cord Introduction Multiple sclerosis (MS) inaugural events usually occur at 20–40 years of age; however, they can occur earlier in life, even in childhood, and thus include the pediatric population [1, 2]. The prevalence of MS onset in childhood/adolescence varies between 2.0% and 4.0% of all MS cases according to several extensive studies [3–5]. It is estimated that 2.3 million people worldwide have MS, with 2.7–10.0% of patients being younger than 18 years [1, 2] and less than 1.0% of patients younger than 10 years [1, 2, 5]. Neuroimaging has been continuously evolving and can help clinicians in the diagnosis and follow-up of MS pa- tients. Advanced imaging techniques have been constantly studied for their appropriate use in different phases of MS pathogenesis. Such imaging techniques have included some controversial points, such as the questionable need for contrast agent in all imaging studies, diffusion- weighted imaging (DWI) in screening, and the routine inclusion of double inversion recovery sequences, all of which remain experimental techniques with the potential to become useful MRI biomarkers [6]. In this review, we discuss the clinical and imaging pe- culiarities of pediatric MS from an initial demyelinating event through MS diagnosis and follow-up. After present- ing a brief overview of the pathophysiology and immuno- logical features of MS, with some distinct features in pe- diatric patients, we critically analyze the first demyelinat- ing episode and the currently adopted diagnostic criteria. Then, we discuss the differential spectrum of inflammato- ry demyelinating disorders that can also compromise childhood. Finally, we include some information concerning modern disease-modifying therapies in this population, highlighting the imaging role in this context. * Igor G. Padilha Igorpadilha.8@gmail.com 1 Division of Neuroradiology, Santa Casa de São Paulo School of Medical Sciences, Rua Dr. Cesário Motta Jr. 112, Vila Buarque, São Paulo, SP 01221-020, Brazil 2 Division of Neuroradiology, Diagnósticos da América AS – DASA, São Paulo, Brazil 3 Division of Neuroradiology, Fleury Medicina e Saúde, São Paulo, Brazil Pediatric Radiology https://doi.org/10.1007/s00247-019-04582-3