As you may know, an Italian surgeon named Paolo Zamboni has proposed that multiple sclerosis (MS) is often due to poor blood drainage from the brain. Improving drainage, he and his colleagues found, reduced MS symptoms. The surgery is called liberation therapy. From this article (thanks, SB) I learned of evidence contradicting Zamboni’s findings:
The studies were independently conducted case–control experiments designed to determine whether abnormal outflow of blood in the head and neck is actually a defining feature of MS. Two of the studies appeared to confirm Zamboni’s observations; the pooled results identified 31 cases of CCSVI out of 35 MS patients and none in 45 matched controls. Yet three other studies, from Germany, Sweden and Holland, with a pooled set of 97 MS patients and 60 matched controls, found no significant evidence of a difference in blood flow between those with MS and those without. In fact, when Doepp et al. attempted to replicate the Zamboni trial they did not find a single case of CCSVI in either the 56 MS patients or the 20 controls examined.
Wow. What intense disagreement. The failure-to-replicate studies used different ways of measuring blood flow so the disagreement is less stark than it appears from this description. But it is still remarkable.
This is highly newsworthy. I can’t think of another case where two different labs have gotten such different results. Unfortunately the article is appalling in its one-sidedness (e.g., liberation therapy is said to have “known risks, unknown benefits”).
How “highly newsworthy” this is depends on how much Zamboni isn’t a crackpot.
If it turns out liberation therapy is bunk, then of course we would expect results like Doepp’s. And the studies in support of Zamboni were wishful thinking, perhaps consciously, perhaps not.
This is precisely why controlled studies or observational studies with n>1 are so important. Anecdotes are fine for generating hypothesis but I’m always concerned with your (Seth’s) enthusiasm for their results. Especially when this runs counter to what people in biology or public health are saying. Being right about some things discovered with self experimentation (probiotics, acne?) doesn’t mean every self experimenter has discovered a medical breakthrough.
p.s. I haven’t read any of the papers.
My wife has multiple sclerosis and she has been evaluated by Dr. Michael Dake, a U.S. colleague of Zamboni’s, for possible evidence of CCSVI. We’ll find out the results next week.
I too am struck by the stark differences in these different studies and am obviously determined to get to the bottom of what might explain the diametrically opposed conclusions. At this point, I have two hypotheses: (1) Zamboni’s diagnostic method was not truly “blind” but involved an element of looking for what he wanted to see; (2) the diagnosis is objective and “blind”, yet complex and subtle, and the measurement of “blood flow” is sensitive to the particular parameters used or to control of possible interfering factors — so that only those with the right technique or understanding can make the correct diagnosis. This second possibility is not uncommon in science — analytical methods are often riddled with artifacts or uncontrolled variables that mess up the analysis if you are not experienced. I’m hoping that the explanation is #2, but I’m realistic enough to realize it could be #1. And my wife and I don’t want to take any chances on a procedure which is based upon a faulty hypothesis or wishful thinking.
Todd
JeffR, a vast number of people (millions?) have taken Zamboni’s results seriously. That’s what makes it newsworthy. Were they all fooled? Or did the non-replicating research teams do a poor job?
Why this disagreement shows “the importance of controlled studies or observational studies with n>1″ I don’t understand. Both sides of this disagreement have such studies. To persuasively criticize self-experimentation, you need to point to self-experimental conclusions that turned out to be wrong. This is unrelated to that.
Todd, keep in mind how hard it is to measure blood flow.
I have been following this debate for some time, and it is apparent that one side, or the other side, is lying.
The theory that the proponents of liberation therapy are telling the truth involves more liars and a larger conspiracy than the theory that the opponents of liberation therapy are telling the truth.
On the other hand, it seems obvious to me that those producing evidence against liberation therapy were committed to getting the results that they got, before they got these results, so I am inclined to think that liberation therapy does work, and its critics are lying, even though this theory requires a larger and more evil conspiracy than the converse theory.
If Zamboni were making all this up, I think we would have heard about it from jealous colleagues. I think that is impossible. On the other hand, I think measurement of blood flow in the brain is really difficult thus allowing the opponents to get the results they prefer — they simply do bad measurements. And since they like the results, they don’t look further. I think the contradictory papers reflect bias. If the scientists who found contradictory results really cared about the question, they would have flown an MS patient in whom Zamboni et al. had detected CCVSI to their lab to make sure they could find CCVSI when it is present.
Acupuncture is similar as far as researchers drawing very different conclusions. Roughly speaking, all Asian researchers get positive results and Western researchers do not. More detail here.
All this conversation about the right method of taking ultrasound pictures is misleading. The golden standard for finding venous obstructions is old fashioned venography accompanied by IVUS. But it’s the underlying question that matters: Is MS of autoimmune or vascular origin? Under this perspective, Zamboni is hardly the first one to talk about blood flow problems. Putnam, Prineas, Behan, Lumsden and Franz Schelling have almost proven that MS is NOT autoimmune.