Computer Simulation Suggests Multiple Sclerosis is a Single Disease

Just thought this was interesting.

http://neurosciencenews.com/multiple-sclerosis-computer-simulation-7828/

Full open access at http://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1005757

 

I haven't looked closely at the study and if I did I wouldn't understand all of the model anyway, but despite possible flaws with such a study I agree it's interesting and I see ME as being a single disease too. I know it's quite popular to predict that ME is in fact half a dozen different diseases but I don't believe it. I think it's one disease with different sets of symptoms coming out in different people.

 

This is an interesting paper. I don't pretend to understand it all, but the general thrust seems to be that there are two phenomena contributing to the symptoms we see in MS.

The first is acute inflammatory episodes. The adaptive immune system (the part of the immune system that learns from experience, the one that produces specialised sets of B and T cells to attack pathogens we've encountered before) goes awry and this ultimately leads to inflammation within the central nervous system - including the brain. This inflammation causes demyelination (degradation of the white material in neurons that facilitates neural transmission), and if severe enough, the person will experience neurological type symptoms. But once the inflammation subsides, these acute symptoms will ease.

However, in addition, these periodic inflammatory attacks have a gradual, cumulative effect on brain volume, and on the overall degree of demyelination, and once that reaches a certain threshold, symptoms will appear to be permanent and indeed will get gradually worse over time.

The idea of the paper is that in relapsing-remitting MS, inflammatory episodes are more widely spaced, so symptoms appear periodically, then seem to resolve completely in between episodes. It takes quite a while before the overall cumulative damage caused by these episodes is sufficient to lead to permanent symptoms. In primary progressive MS, on the other hand, the inflammatory episodes are more closely clustered together. So their cumulative effect occurs sooner.

 

Yea, from our point of view, there are two interesting things. The first is that, as you say, a single disease process can appear to produce very different clinical profiles in different people.

The second is that, in some diseases, the underlying disease process may have been going on for years and years before any outward symptoms appear. Or even any detectable biomarkers. The markers we use to diagnose the disease don't measure the disease itself, just the destruction laid in its wake.

MECFS= no permanent destruction, just ongoing misery. Not convenient for our current, dumb methods of finding disease signatures.

 

I thought this was interesting because it touches on quite big issues not just for MS or ME CFS. We don't really understand an awful lot about many diseases in terms of progression of symptoms, the reality of what remission actually is or the variables that affect initial onset and relapse.

I also think that sub types may be a red herring (but I have an open mind) and just a different set of variables affecting an eventual more predictable outcome.