Multiple Sclerosis and the McDonald Diagnostic Criteria:
A Focused Review with Clinicoradiologic Correlation Abstract Multiple sclerosis (MS) is a chronic immune-mediated demyelinating disorder of the central nervous system characterized by multifocal inflammation, demyelination, and axonal injury. The McDonald diagnostic criteria integrate clinical, radiologic, and laboratory findings to facilitate early diagnosis and treatment initiation. Magnetic resonance imaging (MRI) plays a central role by demonstrating dissemination in space and time. This focused review summarizes the pathophysiology, epidemiology, clinical manifestations, and imaging characteristics of MS, with particular emphasis on MRI-based diagnosis using the McDonald criteria. A representative clinical case involving optic nerve, brain, and spinal cord lesions is used to illustrate practical application of the criteria and common differential diagnostic considerations. Keywords Multiple sclerosis; McDonald criteria; Magnetic resonance imaging; Optic neuritis; Spinal...