Ring-Enhancing Spinal Cord Lesions in Neuromyelitis Optica Spectrum Disorder (P4.145)

OBJECTIVE: To describe the frequency and characteristics of ring-enhancing spinal cord lesions in neuromyelitis optica spectrum disorder (NMOSD). BACKGROUND: NMOSD is an autoimmune aquaporin-4 channelopathy commonly associated with longitudinally extensive transverse myelitis. The gadolinium enhancement patterns of myelitis lesions in NMOSD are not well characterized. DESIGN/METHODS: We identified 283 AQP4-IgG seropositive patients with a history of myelitis seen at Mayo Clinic from 1996-2014. Of these 283 patients, 645 spinal cord MRI’s were screened by two neurologists (N.L.Z and E.P.F) for ring-enhancing lesions. A neuroradiologist (P.P.M) subsequently reviewed these lesions for confirmation. RESULTS: The enhancement pattern was ring-like in 49 of 146 (34[percnt]) myelitis episodes in 40 patients (82.5[percnt] single; 17.5[percnt] multiple ring attacks). A ring-enhancing lesion occurred in the cervical cord, 15 (31[percnt]); thoracic cord, 29 (59[percnt]); and cervico-thoracic cord in 5 (10[percnt]) attacks. A complete ring was seen in 9 (18[percnt]) and an open ring in 40 (82[percnt]). Ring-enhancement was noted on both sagittal and axial images in 35 of 44 (80[percnt]), on sagittal images alone in 4 of 44 (9[percnt]), and on axial images alone in 5 of 44 (11[percnt]) in which both sagittal and axial views were available. The characteristics of ring-enhancing myelitis episodes did not differ from non-ring-enhancing episodes: female sex (86[percnt] vs 90[percnt]; p=0.59); median age at myelitis episode (51 years vs 50 years; p=0.99); need for a cane or worse at nadir (57[percnt] vs 63[percnt]; p=0.65); elevated cerebrospinal fluid (CSF) white cell count (74[percnt] vs 81[percnt]; p=0.71); elevated CSF protein (79[percnt] vs 79[percnt]; p=1.0); and CSF oligoclonal bands (5[percnt] vs 11[percnt]; p=0.59). CONCLUSION: We found ring-enhancement commonly accompanies NMOSD myelitis episodes (34[percnt]) and adds to the spinal MRI findings associated with NMOSD. Patients with ring-enhancing lesions had similar characteristics to patients without ring-enhancing lesions. Disclosure: Dr. Zalewski has nothing to disclose. Dr. Morris has nothing to disclose. Dr. Pittock has received (royalty or license fee or contractual rights) payments from Peripherin-Specific Autoantibodies as a Marker for Neurological and Endocrinological Disease. Dr. Weinshenker has received personal compensation for activities with Novartis, Biogen Idec, Mitsubishi Pharmaceuticals, MedImmune Pharmaceuticals, Chugai, and Chord as a consultant. Dr. Weinshenker has received royalty payments from RSR Ltd. and Oxford Dr. Krecke has nothing to disclose. Dr. Lucchinetti stands to receive royalty payments for commercial assays. Dr. Kaufman has received personal compensation for activities with SpineThera as a consultant. Dr. Wingerchuk has received personal compensation for serving on a clinical trial adjudication committee for Medimmune. Dr. Wingerchuk has received personal compensation in an editorial capacity for The Neurologist. Dr. Wingerchuk has received research su Dr. Flanagan has nothing to disclose.