Accuracy of diagnostic tests in multiple sclerosis - a systematic review

New diagnostic criteria for multiple sclerosis (MS) have been recently proposed and further updates are upcoming. This systematic literature review summarizes diagnostic studies in suspected MS to clarify the value of diagnostic tests. We included studies of at least 40 patients followed up for 2 years. All studies are limited by the fact that no gold standard to validate diagnostic tests is available. A second relapse is used as a surrogate in relapsing-remitting MS, but long follow-up of at least 5 years is necessary to detect all cases. Many studies showed selection bias, partly because of the vague definition of a clinically isolated syndrome. Based on these limitations, sensitivity of magnetic resonance imaging (MRI) criteria was between 35% and 100%, and specificity was between 36% and 92%. Cerebrospinal fluid (CSF) oligoclonal banding showed sensitivities between 69% and 91% with specificities between 59% and 94%. Combination studies of MRI and CSF indicate enhanced sensitivity (56-100%) and specificity (53-96%). Studies on evoked potentials did not justify conclusions about their value. A combination of simplified MRI criteria with CSF might be the best approach for an early MS diagnosis. However, the value of a very early diagnosis stays questionable as patients' benefit of new diagnostic criteria has never been addressed.