From Global Evidence to Saudi Practice: A Structured Evidence Map of the Diagnosis, Molecular Targets, and Therapeutic Strategies of Multiple Sclerosis in the Kingdom of Saudi Arabia

Multiple sclerosis (MS) has shifted in a generation from an uncommon diagnosis in Saudi Arabia to a major cause of neurological disability in young adults. Available Saudi data describe clinical characteristics broadly similar to those reported elsewhere in the Middle East and do not show that Saudi patients differ from trial populations, although this does not establish equivalent efficacy or safety. How far global advances are usable in the Kingdom has not, however, been synthesized. This narrative review maps diagnostic and therapeutic strategies across five separately reported domains (clinical evidence, 2022 national consensus listing, affordability, monitoring requirement, regional data), with categories assigned by a pre-specified rule, not a composite grade. Regional evidence on established therapies is entirely observational: cohorts report favourable outcomes with fingolimod, natalizumab, and off-label rituximab but cannot establish comparative effectiveness, and physicians report cost, availability, and insurance formularies as constraints whose extent has not been quantified. Diagnosis, now based on the 2024 McDonald revision, is transferable in knowledge but depends on AQP4-IgG testing, MRI, and biomarker capacity whose national distribution is undocumented, with neuromyelitis optica spectrum disorder an important differential. Tolebrutinib, recently approved in Europe for non-relapsing secondary progressive MS, and experimental modalities remain regulatory or research questions without regional data. Saudi studies document substantial payer costs of disease-modifying therapy, but none have measured how often cost or infrastructure alters treatment; we propose a prioritized research agenda.