Returning to my comment about the number of patients in our ME support group – I was thinking about this on my slow amble with an elderly dog around the block, and realized that I should have been more mathematically explicit.
Members of our support group do not represent the ME community. Those who are mildly affected (and that's a pretty foul way to describe people who are very ill and struggling to survive) will be doing everything they can to earn a living, so are unlikely to become members. Those who are severely affected are unable to attend meetings, even if it is "only" for a coffee, so again are unlikely to want to become members. I'd be surprised if we represented even a half the ME community. So if 1/500 have a diagnosis of ME, we probably at best only represent 1/1000 at best.
With only 30 members in the group, and with only 3 with EDS, the figure of 10% is very nebulous: we can't extrapolate from that. The numbers can draw attention to a possible problem, but cannot sensibly be used in a calculation.
The prevalence of either ME or EDS rely upon the diagnosis of these conditions from a small number of specialists, and a handful of studies. The reliability of these figures is very poor, particularly with no agreed set of criteria or diagnostic test. (Diagnostic tests have to be interpreted and are much less reliable than the public would like to believe, but with ME we have nothing at all.)
If I were to use the appropriate variety of values for each of these, the results would be wildly different.
But the biggest problem by far would be caused if the numbers of people with EDS were underestimated and the number with ME were overestimated because, like the three members of my group, their first diagnosis was ME rather than EDS, and this simply meant that no further options were considered. This would not have a dramatic effect on the prevalence of ME (which I think is very unreliable anyway), but it would have a significant effect on the estimate of numbers with EDS.
Is it possible that having EDS could result in someone being misdiagnosed with ME? Probably not if they were first sent to someone specializing in EDS, but if they were sent to an ME centre, I have much less confidence that it would be spotted. (Remember that there are areas of the country not covered by such centres, that a proportion of such centres do not have a specialist, and that those that do have specialists have them often from a psychological background). In addition, people with EDS but not yet experiencing problems are just as likely as anyone else (or more likely?) to go down with ME and have that diagnosed first.
Although we can speculate about whether EDS and ME have some form of link, or whether ME could cause similar problems in the neck, it seems to me that the big issue to be addressed is the probability of misdiagnosis.
My friend's GP put in a request for her to see one of the EDS specialists: the funding authority refused it. If access to such specialists is limited, again, how reliable are reports of prevalence and of misdiagnosis?
She did see him privately. He saw the Medserena scan (again that had to be done privately) and commented that the flexion and extension was one of the highest he had seen in EDS.
I wonder why those of us with ME have such mistrust of the system?