Aquaporin-4 autoimmunity in a child without optic neuritis and myelitis

Neuromyelitis optica (NMO) is an inflammatory demyelinating disease with a poor prognosis that is characterized by inflammatory optic neuritis and myelitis. Although it is commonly misdiagnosed as multiple sclerosis (MS), distinguishing NMO from MS is important, as therapeutic approaches approved for MS are ineffective in patients with NMO. The aquaporin-4 (AQP4) antibody is a pathogenic and diagnostic biomarker for NMO. We report an AQP4 antibody-positive 9-year-old female with intractable hiccups and nausea (IHN). Brain imaging revealed lesions in the brainstem, thalami, and hypothalamus. Nevertheless, she had no clinical or radiological signs referable to the optic nerve or spinal cord. We propose that in patients with characteristic IHN associated lesions involving the brainstem or hypothalamus, measurement of AQP4 antibody should be considered for selectivity of treatment, even if the patient has no optic nerve or spinal cord lesions.