Another population-based study in Olmsted County on patients with isolated idiopathic transverse myelitis (based on 2002 ITM diagnostic criteria) found AQP4-IgG-related myelitis to be twice as common as MOG-IgG-related myelitis, although both antibody-positive etiologies accounted for only 14% of total incident cases (51). Here, AQP4 is linked to myelitis.