MRI-only conversion to MS following a clinically isolated syndrome

Declan T Chard (1) , Catherine Mary Dalton (1) , Josephine K Swanton (1) , Leonora K Fisniku (1) , Miszkiel A Katherine (2) , Alan J Thompson (1) , Gordon T Plant (2) , David H Miller (1)

1 UCL Institute of neurology
2 National Hospital for Neurology and Neurosurgery

Objectives: Using current diagnostic criteria, patients who present with a clinically isolated syndrome (CIS) may develop multiple sclerosis (MS) by subsequently exhibiting dissemination in space and time on clinical (clinically definite [CD] MS) or radiological (MRI) grounds. We investigated the frequency of radiological without clinical conversion to MS after long-term follow up as this has not previously been defined. Methods: We investigated two cohorts who underwent serial clinical and MRI studies from presentation with a CIS, and who were followed up over a mean of 6 and 20 years. The distribution and formation of lesions visible on brain MRI were assessed using the revised McDonald criteria (2005). Radiologically defined (RD) MS was determined by fulfilment of the MRI but not CDMS criteria. Results: One hundred and five people were followed-up for 6 years after a CIS, of whom 51% developed CDMS, 15% RDMS, and the remainder were classified as still having had a CIS. Seventy people were followed-up at 20 years, of whom 61% and 11% had developed CDMS and RDMS respectively. Conclusion: About 10-15% CIS patients may develop MS on MRI criteria only, without further clinical events for up to two decades.

Mots clés: MRI; MULTIPLE SCLEROSIS

Declan T Chard, Catherine Mary Dalton, Josephine K Swanton, Leonora K Fisniku, Miszkiel A Katherine, et al.. MRI-only conversion to MS following a clinically isolated syndrome. Journal of Neurology, Neurosurgery and Psychiatry, 2010, 82 (2), pp.176. ⟨10.1136/jnnp.2010.208660⟩. ⟨hal-00557451⟩