Aim of the study: To evaluate and compare the capacity of oligoclonal bands (OB) and three sets of MR imaging criteria to predict the conversion of clinically isolated syndromes (CIS) to clinically definite multiple sclerosis (CDMS).
Patients and methods: One hundred and twelve patients with CIS were prospectively studied with MR imaging and determination of OB. Based on the clinical follow-up (conversion or not conversion to CDMS), we calculated the sensitivity, specificity accuracy, positive and negative predictive value of the OB, and MR imaging criteria proposed by Paty et al, Fazekas et al and Barkhof et al.
Results: CDMS developed in 26 (23.2%) patients after a mean follow-up of 31 months (range 12-62). OB were positive in 70 (62.5%) patients and were associated with a higher risk of developing CDMS. OB showed a sensitivity of 81%, specificity of 43%, accuracy of 52%, positive predictive value (PPV) of 30% and negative predictive value (NPV) of 88%. Paty and Fazekas criteria showed the same results with a sensitivity of 77%, specificity of 51%, accuracy of 57%, positive predictive value of 32% and negative predictive value of 88%. Barkhof criteria showed a sensitivity of 65%, specificity of 70%, accuracy of 69%, PPV of 40% and NPV of 87%. The greatest accuracy was achieved when patients with positive OB and three or four Barkhof's criteria were selected.
Conclusions: We observed a high prevalence of OB in CIS. OB and MR imaging (Paty's and Fazekas' criteria) have high sensitivity. Barkhof's criteria have a higher specificity. Both OB and MR imaging criteria have a high negative predictive value.