# Pediatric-Onset Multiple Sclerosis at Age 10 Following Nephrotic Syndrome: Early Recognition and Successful Treatment With Fingolimod

## TL;DR

A 10-year-old boy with rare pediatric-onset multiple sclerosis was successfully treated with fingolimod after advanced MRI and CSF analysis confirmed the diagnosis.

## Contribution

Demonstrates successful treatment of very early-onset multiple sclerosis using fingolimod and highlights the role of advanced MRI biomarkers in diagnosis.

## Key findings

- Advanced MRI biomarkers, including central vein sign and paramagnetic rim, supported the MS diagnosis in a 10-year-old.
- Fingolimod treatment led to complete clinical and radiological suppression of MS over 18 months.
- Early initiation of high-efficacy therapy improved outcomes in a rare pediatric MS case.

## Abstract

Pediatric-onset multiple sclerosis before the age of 10 is rare and poses significant diagnostic challenges. We report a 10-year-old boy who developed multiple sclerosis five years after remission of nephrotic syndrome. He presented with progressive left eye visual loss and vertigo. Advanced magnetic resonance imaging (MRI) revealed demyelinating lesions with a central vein sign and paramagnetic rim, emerging biomarkers that support the diagnosis of pediatric multiple sclerosis. Cerebrospinal fluid analysis demonstrated type 2 oligoclonal bands, while anti-aquaporin-4 and anti-myelin oligodendrocyte glycoprotein antibodies were negative. The diagnosis of multiple sclerosis was established according to the 2017 McDonald criteria. Early treatment with fingolimod (0.5 mg daily) resulted in complete clinical and radiological disease suppression over an 18-month follow-up period. This case highlights the value of advanced MRI biomarkers in very early-onset multiple sclerosis, the importance of systematically excluding disease mimics in prepubertal children, and the effectiveness of early initiation of high-efficacy disease-modifying therapy. Early recognition and prompt treatment are essential to optimize outcomes in pediatric multiple sclerosis.