Whereas, several studies exist describing transsynaptic damage after optic neuritis and myelitis, the existence of global atrophy, and diffuse tissue alterations of WM and GM in AQP4-IgG seropositive NMOSD is still a matter of debate (13, 58, 63, 64, 93, 95, 111, 113, 114). The gene discussed is AQP4; the disease is optic neuritis.