Pediatric-Onset Multiple Sclerosis Presenting With Persistent Vertigo, Ataxia, and Optic Nerve Atrophy in a...

Pediatric-onset multiple sclerosis (POMS) is an inflammatory demyelinating disorder of the central nervous system that can present with brainstem or cerebellar symptoms and may be initially misattributed to peripheral vestibular etiologies. We report a 15-year-old girl with five days of continuous vertigo described as a sensation that "everything around me is moving," accompanied by unsteady gait and transient unilateral sensory-motor symptoms. Brain magnetic resonance imaging (MRI) with and without contrast demonstrated extensive supratentorial and infratentorial T2-weighted fluid-attenuated inversion recovery (T2/FLAIR) hyperintense lesions in a periventricular distribution with corpus callosum involvement and lesions morphologically suggestive of Dawson's fingers, with both enhancing and non-enhancing plaques. MRI of the orbits showed right-greater-than-left optic nerve atrophy with increased T2 signal without enhancement, consistent with sequelae of prior optic neuritis. Cervical and thoracic spine MRI revealed multiple short-segment T2-weighted hyperintense cord lesions, including an enhancing lesion at C5-C6 compatible with active demyelination. Cerebrospinal fluid (CSF) analysis demonstrated mild pleocytosis, mildly elevated protein, mildly decreased glucose, elevated immunoglobulin G (IgG) index and IgG synthesis rate, and CSF-restricted oligoclonal bands. The patient was treated with five days of high-dose intravenous methylprednisolone followed by an oral corticosteroid taper with significant clinical improvement. This case highlights the importance of considering POMS in adolescents with persistent vertigo and central ocular motor findings, and demonstrates the diagnostic value of combined brain/orbit/spine MRI and CSF immunologic studies for establishing dissemination in space and time and excluding important mimics.