A Combined Neuroimaging and Neuropathological Study for Longitudinally Extensive Spinal Cord Lesions in Neuromyelitis Optica: with Special Reference to Lesion Distribution and Extension Patterns (S46.006)

Backgrounds: Neuromyelitis optica (NMO) is characterized by optic neuritis and longitudinally extensive spinal cord lesions (LESCLs). LESCLs were reported to mainly involve the central gray matter. However, a combined neuroimaging and neuropathological analyses on the distributions of LESCLs has not been done. Objective: To characterize the distribution patterns of LESCLs in patients with NMO or NMO spectrum disorder (NMOSD). Methods: We analyzed the distribution of LESCLs in 31 NMO/NMOSD cases, 15 seropositive and 16 seronegative for anti-aquaporin-4 (AQP4) antibody, by 3-tesla MRI. We also evaluated the distribution of 50 spinal cord lesions from eleven autopsied NMO/NMOSD cases. Results: On MRI, anterior horns (AHs), central portions (CPs) and posterior horns (PHs) were involved in 7/15 (46.7[percnt]), 14/15 (93.3[percnt]), and 14/15 (93.3[percnt]), respectively, in the seropositive cases, and 7/16 (43.8[percnt]), 13/16 (81.3[percnt]), and 13/16 (81.3[percnt]), respectively, in the seronegative cases. Anterior, lateral and posterior columns were affected in 3/15 (20.0[percnt]), 8/15 (53.3[percnt]), and 12/15 (80.0[percnt]), respectively, in the seropositive cases, and 3/16 (18.8[percnt]), 9/16 (56.3[percnt]), and 15/16 (93.8[percnt]), respectively, in the seronegative cases. Snake-eyes appearance, defined as bilateral hyperintensites of the AHs, was found in four seropositive cases (12.9[percnt]). Pathologically, AHs, CPs and PHs were involved in 13/27 (48.1[percnt]), 12/27 (63.0[percnt]), and 15/27 (55.6[percnt]), respectively, in six cases with AQP4 loss, and 7/23 (30.4[percnt]), 8/23 (34.7[percnt]), and 8/23 (34.7[percnt]), respectively, in five cases with preserved AQP4. Anterior, lateral and posterior columns were affected in 13/27 (48.1[percnt]), 17/27 (63.0[percnt]), and 17/27 (63.0[percnt]), respectively, in the AQP4 loss cases, and 9/23 (39.1[percnt]), 15/23 (65.2[percnt]), and 14/23 (60.8[percnt]), respectively, in the preserved AQP4 cases. Peripheral rim-like sparing of the spinal white matter was observed in 3 cases (27.2[percnt]). Conclusion: Our findings suggest that LESCLs in NMO/NMOSD preferentially affect the central and posterior portions. Snake-eyes appearance and spared peripheral rim may reflect tissue hypoxia of LESCLs. Disclosure: Dr. Shotaro has nothing to disclose. Dr. Masaki has nothing to disclose. Dr. Yonekawa has nothing to disclose. Dr. Isobe has received research support from the Uehara Memorial Foundation. Dr. Matsushita has received personal compensation for activities with Bayer Schering Pharma, Pfizer Inc., and Mitsubishi Tanabe Pharma Corporation as a speaker. Dr. Kira has received personal compensation for activities with Biogen Idec.