It was found that in patients with other autoimmune inflammatory disorders of the central nervous system, such as neuromyelitis optica spectrum disorders and myelin oligodendrocyte glycoprotein antibody-associated disease, the frequency of headaches—among others, migraine-like headaches (not optic neuritis-related pain)—is high and can occur as a first symptom or persist during the course of the disease [40,41]. The gene discussed is OMG; the disease is neuromyelitis optica.