OMG and neuromyelitis optica: Serum anti-MPO and P-ANCA were weakly positive, while other indicators including antinuclear, anti-SSA, anti-SSB, anti-dsDNA, anti-Sm, anti-RNP, anti-Scl-70, anti-RP3, anti-GBM, anti-neutrophil cytoplasmic antibodies in cytoplasmic, antibodies to neuro-paraneoplastic syndromes, neuromyelitis optica (NMO), myelin basic protein (MBP) and myelin oligodendrocyte glycoprotein (MOG) in blood as well as cerebrospinal fluid (CSF) were negative.