Detection of central vein should be part of MS diagnostic criteria – No

Abstract

The central vein sign (CVS) has been proposed as a specific biomarker for multiple sclerosis (MS). 1 Although best visualized at ultra-high field magnetic resonance imaging (MRI), recent evidence demonstrates that the CVS can be detected with MRI at 3.0 and 1.5 T, 2-4 making it potentially useful in the clinical practice. The high specificity of the CVS in MS derives from comparisons with other neurological diseases with focal white matter hyperintensities. 5 This is precisely one of the reasons the CVS cannot, at this point, be part of the MS diagnostic criteria. The McDonald criteria were not developed to differentiate MS from other diseases, but to confirm the diagnosis of MS in patients with typical symptoms once other diagnoses have been reasonably ruled out. 6 Nevertheless, incorporating more disease-specific biomarkers in the diagnostic criteria would of course be desirable. In this sense, we could then consider the results of previous studies as proof-of-concept of the high specificity of the CVS in MS lesions, which reflects the perivenous inflammatory demyelination occurring in this disease. To do so, the CVS should be assessed in the context of the 2017 McDonald criteria to determine whether its inclusion does increase the diagnostic specificity while maintaining a high sensitivity.There are, however, several issues to consider first. One is that the CVS can also be seen in diseases other than MS, 5 thus requiring the use of a proportion threshold of lesions with CVS which is usually but not always ⩾40%. 3,4 Using a proportion-based approach is not practical in the daily clinical practice, particularly in patients with a high lesion load. Furthermore, the proportion threshold appears to depend on the type of non-MS diseases the comparison is made against. 3,4,7 Instead, identifying a minimum number of lesions with CVS could simplify its use. However, past efforts in small, retrospective studies have suggested differing cut-offs. Whereas in one of these studies MS was diagnosed if at least 6 out of 10 randomly assessed lesions were perivenular, 8 in the other MS was diagnosed when 3 out of 3 randomly assessed lesions were perivenular. 9 Moreover, a third, small, retrospective study showed that the proportion-based approach, using a 50% and a 40% rule, yielded a higher diagnostic accuracy compared to the six-and three-lesion rule. 3 Another point to consider in these studies is that the mean/median disease duration in patients with MS was 7.7-10.0 years, besides one of the studies including both relapsing and progressive forms of the disease. 3,8,9 With such disease duration, the lesion load would be expected to be high and, at that point in the evolution of the disease, few reasonable doubts about the diagnosis would exist. Diagnosing MS in earlier stages in which the lesion count is usually lower is certainly more challenging. Efforts should thus be directed toward the assessment of the CVS in this setting, especially when considering that the CVS is more difficult to visualize in infratentorial and sp...

Detection of central vein should be part of MS diagnostic criteria – Commentary

“…Despite these clear benefits, before the CVS can be incorporated into diagnostic criteria and widely implemented in clinical settings as a diagnostic tool, a number of issues need to be addressed as pointed out by Arrambide. 5 First, prospective studies evaluating the CVS using the 2017 McDonald Criteria and in those with early MS (ideally at the first clinical presentation) are necessary. Indeed, the majority of studies demonstrating the utility of the CVS in differentiating MS from other WM disorders included those with longer disease durations (>5 years) and utilized prior iterations of the McDonald Criteria.…”