We report the case of a 50-year-old caucasian man presenting with lumbar pain, bilateral ataxia, central facial palsy, ophthalmoparesis and urinary retention. Cerebral MRI hinted a hyperintensity of the medulla oblongata and cervical medulla suggestive of myelitis. Cerebrospinal fluid displayed lymphocytic pleocytosis and elevated protein concentration. Without the possibility to rule out an infectious or inflammatory aetiology, antibiotics and corticosteroids were started. Nevertheless, neurological status deteriorated with loss of muscle strength and left eye amaurosis. A neuroaxis MRI exhibited encephalomyelitis with signal abnormalities involving the pons, medulla oblongata, left optic nerve and cervicodorsal medulla. Although negative for aquaporin-4-IgG antibodies, the patient fulfilled criteria for seronegative neuromyelitis optica spectrum disorder with the presence of multiple core clinical characteristics. Through early institution of corticosteroids, plasma exchange and rituximab, good functional recovery was achieved (Expanded Disability Status Scale score of 2). However, left eye amaurosis persisted despite salvage therapy with intravenous immunoglobulin.