Purpose or Case Report: Pediatric multiple sclerosis (MS) is difficult to diagnose at presentation, and the clinical features often overlap those of acute disseminated encephalomyelitis (ADEM), neuromyelitis optica or clinically isolated syndrome. Established criteria for diagnosing MS are less reliable in pre-pubescent children. We seek to qualitatively and quantitatively define the MRI features of pediatric MS compared to ADEM at initial presentation.
Methods & Materials: A retrospective analysis of MRI scans obtained at first attack from 23 children diagnosed with MS and 15 children with ADEM was performed. T2/FLAIR hyperintense lesions were quantified and categorized according to location and size: distribution (periventricular, juxtacortical, scattered cerebral, scattered, brainstem) and size (S <1 x 1.5 cm; M < 2 x 2.5 cm and L > 2.5 cm.) The largest lesion was diametrically and volumetrically evaluated (Olea Sphere, Olea Medical, La Ciotat, France.) T1W post-contrast images were evaluated for different enhancement patterns: hetero/homogeneous, complete ring, incomplete ring. The presence/absence of “central vein sign” on GRE/SWI images was evaluated.
Results: The median age of the MS patients was 15 years (F: 16, M: 7) and the median age for ADEM patients was 4.5 years (F:8, M:7), with a p value of 0.0. The MS patients had a larger total number of lesions (p = .006), smaller lesion size (p = .002) and more often a periventricular distribution of lesions (p = 0.04) compared to ADEM. The MS lesions showed enhancement more often than ADEM lesions (p = 0.012), however the central veins sign did now show statistical significance, although encountered more often in MS patients (30% vs 13%). No statistical significance was demonstrated between the axial diameter measurements or volumetric quantification of the largest lesion in each group. Comparisons between total lesion volume counts are pending.
Conclusions: Our study suggests that a pediatric patient presenting with neurological symptoms and cerebral white matter lesions is more likely to be diagnosed with MS if it is an older child, there are a large number of lesions, majority of the lesions are less than 1cm, are mainly periventricular in location, and many display contrast enhancement. Conversely, a patient is more likely to be diagnosed with ADEM if it is a younger child, there are overall a smaller number of lesions, many of the lesions are larger than 1cm, are not primarily periventricular and don’t exhibit contrast enhancement.