Laetitia Barbin

1 Introduction Reversible cerebral vasoconstriction syndrome (RCVS) is a neurovascular disorder primarily characterized by recurrent thunderclap headaches and transient cerebral arterial narrowing. Despite increasing recognition, its pathophysiology remains incompletely understood. Several mechanisms have been implicated, including sympathetic hyperactivity, oxidative stress, and disruption of the blood–brain barrier—each contributing to impaired cerebral autoregulation [1-3].

1. Lublin, FD, Reingold, SC, Cohen, JA, et al. Defining the clinical course of multiple sclerosis: The 2013 revisions. Neurology 2014; 83(3): 278–286. Google Scholar | Crossref | Medline | ISI 2. Trapp, BD, Stys, PK. Virtual hypoxia and chronic necrosis of demyelinated axons in multiple sclerosis. Lancet Neurol 2009; 8(3): 280–291. Google Scholar | Crossref | Medline 3. Hartung, H-P, Gonsette, R, König, N, et al.

Objective: To compare natalizumab and fingolimod on both clinical and MRI outcomes in patients with relapsing-remitting multiple sclerosis (RRMS) from 27 multiple sclerosis centers participating in the French follow-up cohort Observatoire of Multiple Sclerosis. Methods: Patients with RRMS included in the study were aged from 18 to 65 years with an Expanded Disability Status Scale score of 0–5.5 and an available brain MRI performed within the year before treatment initiation.