A case-based narrative review of the diagnostic approach to central nervous system demyelinating disorders

Central nervous system demyelinating disorders (CNS-DD) can cause abrupt, disabling, yet potentially reversible neurologic deficits; rapid recognition is essential because acute immunotherapy is timesensitive. This narrative review, anchored in a three-patient case series, outlines a practical diagnostic workflow to differentiate the main inflammatory demyelinating syndromes. We describe: (1) multiple sclerosis in a 23-year-old man with optic neuritis, typical brain MRI lesions, and cerebrospinal fluid oligoclonal bands fulfilling McDonald criteria; (2) aquaporin-4–IgG–positive neuromyelitis optica spectrum disorder in a 24-year-old woman with longitudinally extensive myelitis, optic symptoms, and area postrema syndrome; and (3) MOG antibodyassociated disease in a 23-year-old postpartum woman with ADEM-like encephalopathy and strongly positive serum MOG-IgG. Across entities, lesion topography on brain/spine MRI, CSF profile, and serum antibody testing (AQP4-IgG, MOG-IgG) are pivotal to exclude mimics and guide early treatment.