What Numbers Matter?

Sometimes numbers make me seem a little crazy like my daughters wonderful hair.
Sometimes numbers make me seem a little crazy like my daughters wonderful hair.
I asked for a long time why we cared so much about dots on an MRI if they don’t correlate well with symptoms.  As an MS patient for more than 8 years, I don’t care much about the dots on my MRI.  Still, I can appreciate the goal when we use MRI’s to determine whether our MS is “active” or whether a drug is effective.  We need a measurable, and so we pick a variable we feel gives us the most accurate way to model reality.  Is that not the reason man uses numbers for anything, to describe reality in the way which feels most accurate?
When attempting to solve a problem, one must first define exactly what the problem is.  For us patients, the temptation is to think problem begins and ends with our symptoms.  I think this has been my biggest problem with MRI’s as a measure of MS activity.  Even with a stable MRI, my symptoms progress.  This doesn’t mean MRI’s are not a valid way to measure MS.  It just means MRI’s are not accurate enough to paint the picture I am looking to use.
Over the past few years, I have come to appreciate the inherent logic in dealing with complex systems.  Complex systems are different from complicated systems in that, one can never accurately predict the impact of damage to any one place in the system. They are different from the a->b->c…->z complicated systems where one knows the impact of breaking the chain.  A complex system is more akin to a road system.  Interestingly enough, the complex system theory was designed to replicate the brain, but is more commonly used today for other system models like roads.
One of the studies I found interesting was a recent one showing brain atrophy predicted long term cognitive issues were correlated with brain shrinkage and physical issues were better correlated with flares. http://jnnp.bmj.com/content/83/3/282.long Interesting to me is that neither flares nor shrinkage accurately predicted both.
Brain shrinkage would seem to imply a less able system simply by reducing the size of the system.  Even if we can not identify the specific area of deficit, the sum of all the paths now reaches less than it once did.  If the brain shrinks, the number of alternate paths for signals to take likely shrinks too.  The alternate routes for traffic disappear and the fragility of the system increases, even if it appears traffic is moving at the time.  Shrinkage would seem likely to predict future problems.  This study seems to be validating this assumption at least in terms of cognition.  In doing so, it redefines the problem and measurement of MS.  It is no longer enough to simply look for a flare (think car crash).  One must also look to see if the map still needs folding to carry.
I owe thanks once more to http://multiple-sclerosis-research.blogspot.com for publishing multiple posts about brain atrophy in MS patients.
On a side very cool note, after my interview last week, I was asked to participate on the American Board of Internal Medicine as a patient advocate.  I’m amazed and incredibly honored.  I can hardly wait to find out how I can help.