Epidemiological and clinical characteristics of myelin oligodendrocyte glycoprotein antibody-associated disease in a nationwide survey

Background: To our knowledge, no nationwide epidemiological study of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) has been conducted. Objective: We examined the epidemiology and clinical features of MOGAD in Japan. Methods: We distributed questionnaires on the clinical characteristics of patients with MOGAD to neurology, pediatric-neurology, and neuro-ophthalmology facilities throughout Japan. Results: In total, 887 patients were identified. The estimated number of total and newly diagnosed MOGAD patients was 1,695 [95% confidence interval (CI): 1483-1907] and 487 (95% CI: 414-560), respectively. The estimated prevalence and incidence were 1.34/100,000 (95% CI: 1.18-1.51) and 0.39/100,000 (95% CI: 0.32-0.44), respectively. The median age at onset was 28 years (range: 0-84 years). At onset, optic neuritis was present in approximately 40% of patients, irrespective of the onset age. Acute disseminated encephalomyelitis was more frequent in younger patients, whereas brainstem encephalitis, encephalitis, and myelitis were more frequent in elderly patients. Immunotherapy was highly effective. Conclusion: The prevalence and incidence rates of MOGAD in Japan are similar to those in other countries. Notable characteristics such as the preferential occurrence of acute disseminated encephalomyelitis in children exist; however, general characteristics including symptoms and treatment response are common irrespective of the onset age.