Central nervous system aquaporin-4 autoimmunity presenting with an isolated cerebral abnormality

Advances in the understanding of central nervous system aquarporin-4 autoimmunity have promoted the recognition of diverse clinical presentations beyond the traditional view of neuromyelitis optica. We describe a patient who developed hemiparesis caused by an extensive cerebral lesion as an initial manifestation of central nervous system aquarporin-4 autoimmunity. Although the patient had no history of optic neuritis or myelitis, not only was serum anti-aquarporin-4 antibody positive, but an imaging, treatment response and histopathological features also revealed characteristic findings suggestive of central nervous system aquarporin-4 autoimmunity. The present case highlights the importance of a comprehensive evaluation for anti-aquarporin-4 antibody even in patients presenting with isolated cerebral lesions.