Real world prognosis in MS: does early versus late diagnosis matter?

Background: Multiple sclerosis (MS) often presents soon after the onset of a recognized clinically isolated syndrome (CIS). In order to interpret data from CIS trials, it is important to know whether patients presenting as classical CIS provide group data representative of RRMS. Objective: We aimed to determine whether or not MS patients presenting soon after the onset of symptoms with clinically isolated syndromes have an identifiable clinical profile, including worse outcomes, versus MS patients presenting later. Methods: Chart review of consecutive patients with newly diagnosed relapsing MS, diagnosed in our clinic between 1989 and 2005. We divided patients into an early presentation group (EP), versus the remaining late presenting group (LP), and analyzed the impact of delay in presentation on 10- and 15-year disability outcomes. We also sought to identify reasons for later presentation. Results: The two groups were similar in terms of many demographics, clinical risk factors, and long-term disability outcomes (median EDSS 2.25 versus EDSS 2.0 at 10 years). Exceptionally, patients in the EP group had more frequent attacks in the first few years after onset and were diagnosed and treated earlier. Conclusions: Patients in our MS clinic with EP versus LP were more likely to have multiple attacks in the first 2 years after onset and were treated earlier, but did not have a better 10- or 15-year outcome.