MRI predictors of early conversion to clinically definite MS in the CHAMPS placebo group

Objective: To assess the ability of baseline MRI characteristics to predict the early development of clinically definite MS (CDMS) and combined CDMS/MRI outcomes in 190 patients with a positive MRI at the time of their first demyelinating event. Methods: Based on individual and sets of baseline MRI characteristics, the authors evaluated the percentage of patients meeting outcomes of CDMS and various combined CDMS/MRI outcomes by 18 months. They also optimized a cutpoint for dichotomizing each baseline MRI characteristic and evaluated these variables using logistic regression to determine which MRI characteristics best predicted CDMS by 18 months. Results: The presence of two or more gadolinium-enhancing lesions better predicted the development of CDMS and combined CDMS/MRI outcomes by 18 months than any other individual MRI characteristic or set of MRI characteristics. Among patients with two or more gadolinium-enhancing lesions, 52% developed CDMS compared with 24% of patients with fewer than two lesions. For those meeting the criteria of Barkhof et al., 32% of patients developed CDMS compared with 16% of those not meeting these criteria. Irrespective of individual or sets of criteria, however, the majority of patients developed either CDMS or demonstrated disease activity on brain MRI by 18 months. Conclusions: For patients with positive MRI at the time of their initial neurologic event, both gadolinium-enhancing lesions and the Barkhof criteria are predictors for development of CDMS over a short interval. However, these results, based on a combined CDMS/MRI outcome, suggest that the majority of these patients are already in the earliest stages of MS, regardless of whether any further MRI criteria are met.