COMPARISON OF MRI CRITERIA AT FIRST PRESENTATION TO PREDICT CONVERSION TO CLINICALLY DEFINITE MULTIPLE-SCLEROSIS

We compared MRI criteria used to predict conversion of suspected multi ple sclerosis to clinically definite multiple sclerosis. Seventy-four patients with clinically isolated neurological symptoms suggestive of multiple sclerosis were studied with MRI. Logistic regression analysis was used to remove redundant information, and a diagnostic model was built after each MRI parameter was dichotomized according to maximum a ccuracy using receiver operating characteristic analysis. Clinically d efinite multiple sclerosis developed in 33 patients (prevalence 45%). The optimum cut-off point (number of lesions) was one for most MRI cri teria (including gadolinium-enhancement and juxtacortical lesions), bu t three for periventricular lesions, and nine for the total number of T-2-lesions. Only gadolinium-enhancement and juxta-cortical lesions pr ovided independent information. A final model which, in addition, incl uded infratentorial and periventricular lesions, had an accuracy of 80 %, and having more abnormal criteria, predicted conversion to clinical ly definite multiple sclerosis strongly. The model performed better th an the criteria of Paty et al. (Neurology 1988; 38: 180-5) and of Faze kas et al. (Neurology 1988; 38: 1822-5). We concluded that a four-para meter dichotomized MRI model including gadolinium-enhancement, juxtaco rtical, infratentorial and periventricular lesions best predicts conve rsion to clinically definite multiple sclerosis.