However, the incidence of reported brain abnormalities increased to 50–85% of patients fulfilling the 1999 NMO criteria [12] with the exception of the brain MRI criterion or revised 2006 NMO criteria (Table 2) [22–27] and to 51–79% of AQP4-Ab-seropositive patients [28, 29]. Here, AQP4 is linked to neuromyelitis optica.