Case report: Neuromyelitis optica spectrum disorder in a patient presented with orbital apex syndrome

Orbital apex syndrome as the presentation of neuromyelitis optica spectrum disorder has not been reported in literature. We reported a case in which the patient initially presented with ptosis, diplopia, ophthalmoplegia and visual impairment of the right eye. Clinical examination revealed no light perception in the right eye with the presence of relative afferent pupillary defect and involvement of cranial nerves II, III, V, and VI. Magnetic resonance imaging of the cranial and orbital regions revealed thickening in the intraorbital segment of the right optic nerve with T2-weighted hyperintensity, and Gadolinium-enhancement of the right optic nerve and its myelin sheath. Longitudinally extensive transverse myelitis subsequently developed, with detection of serum anti-aquaporin-4 antibody. Intravenous methylprednisolone was initiated, leading to significant clinical improvement. This case report highlights the diverse manifestations of neuromyelitis optica spectrum disorder, including the orbital apex syndrome.