A 51-year-old teacher presented with diplopia and vertiginous symptoms 6 months after cochlear implant insertion, which had been complicated by infection around the implant site. This evolved into a partially steroid-responsive relapsing disorder with sequential ataxia, CN-VI palsy, optic neuritis and a predominantly sensory spinal cord syndrome. Initial investigations were unremarkable (including negative CSF oligoclonal bands) apart from an abnormal VEP confirming previous optic neuritis. MRI was precluded by the cochlear implant. With no clear alternative diagnosis, she was started on MS disease modifying therapy, but continued to deteriorate. On re-investigation, a diagnostic test was performed. The patient was found to be MOG-antibody positive. This case highlights the difficulties encountered when investigating neuroinflammatory conditions without MRI. There remains a question as to whether the implant infection triggered the onset of her neuroinflammatory disorder. It is conceivable that infection-associated immunological changes or blood-brain barrier disruption could promote CNS auto-antigen generation. Despite not having bilateral optic neuritis or a significant motor spinal cord relapse during the disease course, she illustrates many features recently described as part of the expanding phenotype of neuromyelitis optica spectrum disorder. Given the aggressive disease course, early recognition is vital to ensure early treatment to prevent disability accumulation.