Neuromyelitis Optica Spectrum Disorder (NMOSD): Brain MRI findings in patients at our institution and literature review. Poster No.: C-0817 Congress: ECR 2014 Type: Educational Exhibit Authors: G. I. MICHELIN, V. sarmiento, C. Rollan, M. M. SERRA, P. Yañez; Buenos Aires/AR Keywords: Neuroradiology brain, CNS, MR, Diagnostic procedure, Education, Education and training, Inflammation DOI: 10.1594/ecr2014/C-0817 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 11
Learning objectives To increase knowledge of brain imaging findings in patients with NMOSD. To retrospectively analyze brain MRI imaging on patients with NMOSD in our institution and try to define characteristic findings. Background Neuromyelitis Optica (NMO) is an inflammatory disorder associated with autoantibodies against Aquaporin 4 (AQP4), a cell membrane water channel that is found in astrocyte foot processes at the glial limiting membrane. AQP4 plays a major role in fluid homeostasis of the CNS.[2] The binding of AQP4 -IgG to AQP4 is thought to cause complement-dependent cytotoxicity, which leads to leukocyte infiltration, cytokine release and breakdown of the blood-brain barrier. These events are followed by oligodendrocyte death, myelin loss and finally neuron death.[3] Classically defined as a pathology limited to the optic nerves and the spinal cord, in the last years brain imaging findings were described showing characteristics that could help define the diagnosis. Typical NMO brain lesions follow the distribution of AQP4, such as periependymal lesions that surround the lateral ventricles, the third ventricle and the cerebral aqueduct. However less specific brain imaging changes are being recognized, involving regions without high expression of AQP4 like the corticospinal tracts or the hemispheric white matter.[1] Identification of brain lesions not only is important for reaching an accurate diagnosis, but also has been shown to present a clinical correlation, with symptoms depending on the affected region, such as hiccups and nausea in brainstem lesions; cognitive symptoms and seizures in cortical/subcortical compromise; and narcolepsy and anorexia when hypothalamus is affected.[4] Findings and procedure details We described the MRI findings of 11 patients with diagnosis of NMOSD (10 females and 1 male, between 25 and 59 years of age) that presented at our institution in the period Page 2 of 11
between February 2007 and October 2013. MRI scans were performed in 1.5 and 3.0 Tesla scanners. Our imaging protocol for this patients included DWI, T1WI, T2WI, FLAIR, SWI and post-contrast sequences. Of our patients (11), 82% (9) presented brain lesions, of these, 89% (8) showed periependymal lesions, following the distribution described for Aquaporin 4, which represented the most frequent finding (Fig 1, 2, 3). Corpus callosum compromise was found in 55% (5) of our patients consisting on focal T2 hiperintense lesions or diffuse lesions, mostly with periependymal distribution (Fig. 4). Supratentorial white matter lesions were found in 55% (5) of our patients, mainly characterized by punctuate or small hyperintense lesions with preferential distribution amongcorticospinal tractsin three (3) patients (Fig.3, 4, 5). Two (2) subjects presented confluent T2 hyperintense white matter lesions without mass effect (Fig. 5). Infratentorial white matter lesions were found in 45% (4) of our patients with lesions described among medulla, cerebellar pons, cerebellum and midbrain (Fig.6, 7). Different patterns of contrast enhancement were found in 78% (7) patients including periependymal enhancement, homogeneous and heterogeneous lesion enhancement (Fig. 2, 3, 7). Images for this section: Page 3 of 11
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Fig. 1: Axial Flair sequence shows periacueductal hyperintensity (arrow) in a 53 years old female patient with NMOSD. Fig. 2: 36 years old female patient with NMOSD. A: Sagital FLAIR T2WI shows periependimal hyperintensity adyacent to lateral ventricles. B: Coronal T1+C shows periependimal enhancement. Page 5 of 11
Fig. 3: A: Axial Flair image shows periependymal (white arrow), thalamic (arrowhead) and subcortical (blue arrow) compromise in a 27 years old female patient with NMOSD. B: Same patiente presented subinsular lesion enhancement in T1C+. Page 6 of 11
Fig. 4: A: 27 years old female patient with NMOSD. Axial FLAIR T2WI shows focal hyperintense lesions within corpus callosum s body. Focal hyperintense lesions are also appreciated bilaterally on frontal white matter. B: Sagital FLAIR T2WI shows diffuse hyperintensity involving the undersurface of corpus callosum in a 59 years old, female patient with NMOSD. Page 7 of 11
Fig. 5: A: 57 years old female patient with NMOSD. Axial FLAIR T2WI, shows punctuate and small hyperintense lesions bilaterally in frontal and parietal white matter. B: Axial FLAIR T2WI show confluent white matter lesions adjacent left ventricular atrium in a 29 year old patient with NMOSD. Page 8 of 11
Fig. 6: 6: 55 years old female patient with NMOSD. Axial and sagital FLAIR T2WI showed hyperintense focal lesions in left cerebellar pons. Page 9 of 11
Fig. 7: 25 years old male patient with NMOSD. A: Axial FLAIR T2WI shows diffuse hyperintense lesions within the medulla and cerebellar amigdalas. B and C: Axial T1WI C+ shows intense enhancement of these lesions at medulla, vermis and cerebelellar amygdales. Page 10 of 11
Conclusion Concurring with the latest discoveries regarding NMOSD, we found that 82% of our patients showed different patterns of brain involvement, periependymal lesions being the most frequent finding. Although these lesions are not specific enough to be use as single diagnostic criteria, when NMOSD is suspected, knowledge of characteristic brain lesions may help approach the accurate diagnosis. Personal information References 1- Woojun Kim, Su-Hyun Kim, So-Young Huh, Ho Jin Kim. Brain Abnormalities in Neuromyelitis Optica Spectrum Disorder. Mult Scler Int. 2012; 2012: 735486. 2- Barnett Y, Sutton IJ, Ghadiri M, Masters L, Zivadinov R, Barnett MH. Conventional and Advanced Imaging in Neuromyelitis Optica.AJNR Am J Neuroradiol. 2013 Jun 13. 10.3174/ajnr.A3592. 3- Ratelade J, Verkman AS. Neuromyelitis optica: aquaporin-4 based pathogenesis mechanisms and new therapies.int J Biochem Cell Biol. 2012 Sep;44(9):1519-30. 4- Lana-Peixoto MA, Callegaro D. The expanded spectrum of neuromyelitis optica: evidences for a new definition.arq Neuropsiquiatr. 2012 Oct;70(10):807-13. Page 11 of 11