Research Article Periventricular Lesions Help Differentiate Neuromyelitis Optica Spectrum Disorders from Multiple Sclerosis Eytan Raz, 1 John P. Loh, 1 Luca Saba, 2 Mirza Omari, 3 Joseph Herbert, 3 Yvonne Lui, 1 and Ilya Kister 3 1 Department of Radiology, New York University School of Medicine, 660 First Avenue, New York, NY 10026, USA 2 Department of Radiology, Azienda Ospedaliero Universitaria, di Cagliari Polo di Monserrato, SS 554 Monserrato, 09045 Cagliari, Italy 3 NYU Multiple Sclerosis Center, Department of Neurology, New York University School of Medicine, 240 East 38th Street, New York, NY 10026, USA Correspondence should be addressed to Ilya Kister; ilya.kister@gmail.com Received 16 August 2013; Accepted 19 December 2013; Published 9 February 2014 Academic Editor: Hayrettin Tumani Copyright © 2014 Eytan Raz et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Objective. To compare periventricular lesions in multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOsd). Materials and Methods. Sagittal and axial luid attenuated inversion recovery (FLAIR) sequences of 20 NMOsd and 40 group frequency-matched MS patients were evaluated by two neuroradiologists. On axial FLAIR, periventricular area was characterized as free of lesions/smooth-bordered (“type A”) or jagged-bordered (“type B”) pattern. On sagittal FLAIR, the images were evaluated for presence of “Dawson’s ingers.” Results. Type A pattern was observed in 80% of NMOsd patients by Reader 1 and 85% by Reader 2 but only in 5% MS patients by either Reader. Type B was seen in 15% NMOsd patients by Reader 1 and 20% by Reader 2 and in 95% MS patients by either Reader. Dawson’s ingers were observed in no NMOsd patients by Reader 1 and 5% by Reader 2. In MS, Dawson’s ingers were seen in 92.5% patients by Reader 1 and 77.5% by Reader 2. he diferences in periventricular patterns and Dawson’s inger detection between NMOsd and MS were highly signiicant ( < 0.001). Conclusions. Dawson’s ingers and “jagged-bordered” periventricular hyperintensities are typical of MS and almost never seen in NMOsd, which suggests a practical method for diferentiating the two diseases. 1. Introduction Neuromyelitis optica (NMO) was originally conceived as a disease with predominantly opticospinal predilection, but recent studies revealed brain involvement on MRI in up to 80% of patients [1]. Some brain lesions of NMO have distinct enhancement patterns [2, 3] and lesion morphology [4, 5], but no speciic set of radiologic criteria has been validated for NMO. Periventricular lesions have been reported in NMO [1, 6–8] and linear anterior periventricular linear lesions have been noted to be characteristic of NMO [8]. In MS, periven- tricular hyperintensities are common and radial callosal lesions—“Dawson’s ingers”—are a helpful radiologic clue to this diagnosis. Dawson’s ingers are elongated, lame-shaped, hyperintense lesions best seen on sagittal FLAIR images. hey are oriented along subependymal veins and thus are perpendicular to the walls of lateral ventricles [9, 10]. Patho- logically, Dawson’s ingers correspond to areas of perivenous inlammation. We hypothesized that radiographic evidence of perivenous inlammation (Dawson’s ingers or “jagged- bordered” hyperintense signal) is absent or rare in NMO and that examination of periventricular white matter may therefore help to diferentiate NMOsd from MS. 2. Materials and Methods In the NMOsd group, we included only patients with a history of recurrent optic neuritis and/or longitudinally extensive transverse myelitis and seropositivity for anti-AQP4 antibody. All adult NMOsd patients fulilling the above Hindawi Publishing Corporation Multiple Sclerosis International Volume 2014, Article ID 986923, 5 pages http://dx.doi.org/10.1155/2014/986923