Unrecognized neuromyelitis optica spectrum disorder with pontine and corpus callosum microhemorrhage

Introduction: Neuromyelitis optica spectrum disorder (NMOSD) represents an immune-mediated neuroinflammatory syndrome, classified as separate entity after discovery of aquaporin-4 immunoglobulin G antibodies (AQP4-IgG). The neuroimaging spectrum of NMOSD classically consisted of bilateral optic neuritis and longitudinally extensive transverse myelitis (LETM), recently broadened with lesions in area postrema, diencephalon, brainstem and cerebellum, and extensive cord atrophy. Case report: Here we present a case of an AntiAQP4-positive 65-year old female patient who initially presented with underappreciated LETM and developed multiple cerebral and cerebellar lytic demyelinating lesions associated with acute long segment optic nerve involvement two years later. Two new imaging findings are described in this case: the involvement of complete cross-sectional area of pons and microhemorrhage in the pons and corpus callosum. Conclusion: Raising suspicion of NMOSD is of a crucial importance in cases with isolated LETM in order to prevent relapses in Anti-AQP4 positive cases, improve patient outcome and recovery.