I see that Colleague Kingston is unsure why the federal Minister of Health is frustrated at media coverage of her ministry’s approach to the vein-centered Zamboni hypothesis about multiple sclerosis. One possible reason, I think, is that statements like those of Liberal health critic Kirsty Duncan are being repeated rather uncritically. Duncan told Kingston “They say we need evidence-based medicine but they are doing nothing to gather evidence.” Nothing? I wonder how else, but as “evidence-gathering”, one could possibly characterize the seven MS Society-funded preliminary studies Aglukkaq mentioned in her burst of finger-wagging at the media. These studies are designed to establish precisely what needs to be confirmed before the dream of a pan-Canadian trial of vein therapy for MS can appropriately be fulfilled: namely, whether there is any such thing at all as “chronic cerebrospinal venous insufficiency”, and whether it is really correlated with MS.
The religious conviction of some MS patients that they have a venous disorder is hard to account for, given the state of the evidence. It seems to be a by-product of natural frustration with slow progress on MS treatment, and, often, of conspiracy theories about sadistic drug companies and greedy, arrogant “neuros”. Some of these patients now reject the idea that they have multiple sclerosis at all—and, indeed, one must admit that there is something refreshingly categorical about such views. MS is not diagnosed by direct observation of demyelination, after all, but largely by means of functional criteria. The idea that CCSVI is not MS at all sidesteps the multiple logical problems with attributing MS to CCSVI. (One obvious example: why doesn’t anybody develop MS beyond middle age, even as the vascular system in most humans continues to fall into ever-worse disrepair?) I suspect it is almost easier to believe that there are some non-MS patients whose real problem might be a chronic vein blockage than it is to believe that MS, which is known to be a demyelinating disease, is caused or worsened by such blockages.
The problem with making grandiose statements about this wholly novel ontological entity, CCSVI, seems similar to the one that plagued the field of back surgery until fairly recently: patients presenting with chronic lower-back pain would be given MRIs, and a surgeon would go “Ahhh, here’s your problem”, point to some apparent lesion—a “slipped disc” or the like—and recommend an expensive, disabling operation. We now know, because people got around to checking by means of controlled investigations, that many of these lesions are indistinguishable from ones commonly found in asymptomatic individuals. Put in plain English, everybody’s back kind of looks like hell in an MRI, because we are imperfectly evolved to walk upright. Stronger criteria have thus been established for surgical interventions into chronic lower back pain, and even for mere medical imaging of bad backs. Something similar is likely to happen with tonsillectomies for children, which are increasingly thought to have been performed much too commonly in the past (although the rates at which they are done seem to be about as high as ever).
Like it or not, medicine no longer cuts first and asks questions later. We can’t presume CCSVI into existence; we have to ascertain the natural background rate of vein blockages, even ones that look dramatic in a venogram. You can see for yourself that this is the basic aim of the studies Aglukkaq points to; all seven involve vascular comparisons of MS patients with healthy controls.
For the record, I would like to politely distance myself from any suggestion that the strongly evidence-based treatments developed for vein-obstruction problems in the legs should be used, on the premise of a “right to blood flow”, to justify vaguely analogous and non-evidence-based treatments in the region of the head and neck. I would also like to observe that surgery for varicose veins does not normally involve surgical widening of the affected vessels with balloons or stents: instead, the veins are simply removed, perforated, or destroyed, precisely because a sufficient volume of blood can be counted on to return to the heart from the leg through other tissues.