Pediatric Multiple Sclerosis: Unveiling the Trajectory of a Toddler-Onset Case

Pediatric multiple sclerosis (MS) is predominantly a relapsing-remitting demyelinating disorder. Toddler-onset MS (12–36 months) is rarely studied despite the likelihood of early-life adversity influencing its incidence. In this case, we present a 9-year-6-month-old girl who first exhibited symptoms at 30 months. Her disease course reflects the challenging mission of reaching a definitive MS diagnosis. Noteworthy observations include a complex perinatal history, initially normal diagnostic workup, and complete recovery after each relapse. It is crucial to recognize the hidden dynamics of MS, namely smoldering MS and the related progression independent of relapse activity, to commence a high-efficacy early treatment modality and establish a comprehensive multidisciplinary management strategy.