ORIGINAL COMMUNICATION Risk of multiple sclerosis following clinically isolated syndrome: a 4-year prospective study Roberto D’Alessandro • Luca Vignatelli • Alessandra Lugaresi • Elisa Baldin • Franco Granella • Maria Rosaria Tola • Susanna Malagu ` • Luisa Motti • Walter Neri • Massimo Galeotti • Mario Santangelo • Laila Fiorani • Enrico Montanari • Cinzia Scandellari • Maria Donata Benedetti • Maurizio Leone Received: 27 October 2012 / Revised: 8 January 2013 / Accepted: 9 January 2013 Ó Springer-Verlag Berlin Heidelberg 2013 Abstract The aim of the study was to estimate the rate of conversion from clinically isolated syndrome (CIS) to multiple sclerosis (MS) and to investigate variables pre- dicting conversion in a cohort of patients presenting with symptoms suggestive of MS. Patients with a first symptom suggestive of MS in the preceding 6 months and exclu- sion of other diseases were enrolled in an observational prospective study from December 2004 through June 2007. Conversion from CIS to MS according to both McDonald and Clinically Defined Multiple Sclerosis (CDMS) criteria was prospectively recorded until March 2010. The multi- variate Cox proportional hazard model was used to assess the best predictive factors of conversion from CIS to MS. Among 168 patients included in the analysis, 122 con- verted to MS according to McDonald criteria whereas 81 converted to MS according to CDMS criteria. The 2-year probability of conversion was 57 % for McDonald Criteria For the GERONIMUS Study Group (members of this study group are listed in ‘‘Appendix’’). R. D’Alessandro (&) Á L. Vignatelli Á E. Baldin Department of Neurological Sciences, Neuroepidemiology Unit, University of Bologna, Via U. Foscolo 7, 40100 Bologna, Italy e-mail: daless.rob@iol.it; roberto.dalessandro@aosp.bo.it; roberto.dalessandro@unibo.it L. Vignatelli City of Bologna Local Health Trust, Bologna, Italy A. Lugaresi Dipartimento di Neuroscienze ed Imaging, Centro Sclerosi Multipla, Clinica Neurologica, Universita ` ‘‘G.d’Annunzio’’, Chieti, Italy E. Baldin Gertrude H. Sergievsky Center, Columbia University, New York, USA F. Granella Department of Neurosciences, Multiple Sclerosis Centre, University of Parma, Parma, Italy M. R. Tola UO Neurologia, AOU S.Anna, Ferrara, Italy S. Malagu ` UO Neurologia, Ospedale Bufalini, Cesena, Italy L. Motti UO Neurologia, AO Santa Maria Nuova, Reggio Emilia, Italy W. Neri UO di Neurologia, AUSL di Forlı `, Forlı `, Italy M. Galeotti Á L. Fiorani UO di Neurologia, Ospedale santa Maria delle Croci, Ravenna, Italy M. Santangelo UO di Neurologia, Ospedale Ramazzini, Modena, Italy E. Montanari UO di Neurologia, Ospedale Civile–Localita ` Vaio, Fidenza, Parma, Italy C. Scandellari UOSD Riabilitazione e Sclerosi Multipla, Villa Mazzacorati, IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy M. D. Benedetti UOC di Neurologia dU, Centro Malattie Demielinizzanti, Borgo Roma, Aziende Ospedaliera Universitaria Integrata, Verona, Italy M. Leone SCDU Neurologia, AOU Maggiore della Carita `, Novara, Italy 123 J Neurol DOI 10.1007/s00415-013-6838-x