 Anyway, it is reported that all MS cases have an active subclinical phase before the CIS

It has been noted that some aspects of the MS underlying condition are present in otherwise healthy MS patients' relatives, suggesting a wider scope for the "silent MS" term.In these cases Interleukin-8 is a risk for clinical conversion.It has also been proposed that always exists a subclinical phase in the beginning of every MS case, during which the permeability of the BBB can be used for diagnosis

It is also under investigation whether MS has a prodrome, i.e., a preliminary stage in which the disease exists with non-specific symptoms.