MS patients try a long list of things to slow or reverse the march of our disease. How do we know what's working and what isn't? EDSS is a crude metric that measures changes over years - but many don't have the patience to continue with things that may or may not have an impact.
It seems to me that more sensitive metrics may be possible if we accept that metrics have to be individualized at the edge of each patients abilities. I have been using one leg stand times to track my progress.http://enhancedbiotintrial.blogspot.com/2015/05/updated-metrics-chart.html?m=1
This is a good metric for me today because I can't stand on one leg easily but I can barely (edge of my ability). It would be meaningless for my wife who can stand on one leg until she gets bored and it would be meaningless for someone who has trouble standing on both legs.
It may be possible to devise a range / toolkit of standardized metrics to satisfy the need for objectivity / standization. TW25 is a good metric for some, but one size does not fit all.