Sidney Crosby, chiropractic neurology, and the limits of evidence


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The good news: Sidney Crosby is back from the concussions that kept him on the bench for more than 10 months, and he had two goals and two assists in his return against the Islanders last night. But one downside, a reader pointed out to me in an e-mail, is that Crosby’s return may give added credibility to “chiropractic neurology,” the alternative therapeutic approach that Crosby turned to during his rehab. What exactly is this? I don’t know — and I’m not alone:

It’s a field that’s unfamiliar to many traditional doctors, including Randall Benson, a neurologist at Wayne State in Detroit who has studied several ex-NFL players. Says Benson, “It’s very difficult to evaluate what kind of training, expertise or knowledge a chiropractic neurologist has since I have never heard of [the discipline].”

That’s a quote from David Epstein and Michael Farber’s excellent look at Crosby’s rehab from Sports Illustrated in October. A couple of other interesting quotes:

In 1998, at Parker University, a Dallas chiropractic college, Carrick [the chiropractic neurologist who Crosby worked with] worked on Lucinda Harman before 300 students. Two car accidents and a neurotoxic bite from a brown widow spider had left Harman, herself a Ph.D. in experimental psychology, wheelchair-bound and with headaches, during which she saw spots.”[Carrick] asked if they were red and yellow,” she says. “I said, ‘No, they’re green, blue and purple.’ ” Carrick informed the audience that this meant her brain was being drastically deprived of oxygen and that, without treatment, she had six months to live. Harman, now 59, says simply, “Miracle.” But Randall Benson says that “there’s nothing out in peer-reviewed literature supporting” an association between the color of spots a patient sees during a headache and the severity of the oxygen deprivation in the brain.


Carrick, who has had a handful of studies that have appeared in scientific journals, has never published data on vestibular concussions. “We don’t have enough time to publish studies,” he says, “but we’re doing a large one at Life [University] right now.”

It’s a great piece — fair but rigorous. In some ways, though, the most important quote may be the kicker:

“I don’t think this is a case of trying to do something wacky,” Crosby says. “When someone came along and invented the airplane, people must have thought they were out of their mind. Who thinks he can fly? I’m sure people thought that person might have been stretching it a bit… . At the end of the day, as long as the person getting the care is comfortable, I think that’s what’s important.

Much as my evidence-based personality protests, I do think there’s some truth to that. Especially in cases like this, where — as with so many health conditions — there isn’t a well-established “standard-of-care” treatment. It’s totally different from, say, Steve Jobs choosing “alternative” forms of cancer treatment instead of surgery. In that case, the potential benefits of the surgery are well-known and well-understood. But many people face health conditions where the verdict of the Cochrane review is basically “there is insufficient evidence to conclude that ANY interventions do any good.” In that case, it’s hard to argue against trying other, unproven approaches rather than simply doing nothing.

Of course, sports medicine is a little different — it’s not life-or-death. For pro athletes, the incentive to try anything and everything in order to return to play (and earn money during their brief career window) is enormous. If I were Tiger Woods or Terrell Owens, I would have tried platelet-rich plasma to speed tendon healing too, despite the lack of evidence that it actually works. The problem is that the use of these therapies by sports stars gives the general public the impression that they’re proven, established treatments — hence the huge surge in PRP over the last few years. Will the same thing happen with chiropractic neurology? I hope not. But on the other hand, if someone who’s been in two car accidents and been bitten by a neurotoxic spider is in pain and hasn’t been able to get relief from conventional treatment, I’d have a hard time criticizing them if they decided to give it a try.

14 Replies to “Sidney Crosby, chiropractic neurology, and the limits of evidence”

  1. I think that this article raises some good issues on evidence, or lack thereof, for many treatments. However I think that traditional medical treatments need to be held under the same microscope and standard of evidence. Much of the treatments (from all disciplines) rely soley on clinical evidence, and not the same repeated evidence necessary for the rest of the scientific community. This is unfortunate. And even more unfortunate is the media and its effect on perception- as you have raised here. People with cultural influence are dictating treatments and driving the public to place demands on clinicians. If we look at the evidence on long term outcomes for low back surgery they are atrocious, while manipulation and exercise has gobs of evidence for its efficacy. Yet many still have negative views of this treatment. So I agree with your point of view here, but also think that we need to be truly informed of traditional medicine’s lack of evidence as well, before we start getting nervous about chiropractic neurology. Especially since it is fairly non invasive.

    Full disclosure- I am a chiropractor, and therefore biased. But functional (chiropractic) neurology is doing amazing things for a portion of the population that traditional medicine has little effect- and frankly i personally think it represents the future of conservative care.

  2. @Drew: For sure, issues of evidence (and lack thereof) aren’t specific to chiropractors. I’ve spent plenty of time on this blog questioning the benefits of, for example, platelet-rich plasma!

  3. I’ve been following this story closely because as a new chiropractor (from one of the most strictly evidence-based schools out there), I really found it odd that I had never even heard of chiropractic neurology…ever.

    The one problem I have with this entire story is that Carrick seems to be implementing his technique with confidence (or is this just the media’s portrayal)? Either way, I have no issue with using low risk, low cost, non-invasive alternative treatments on a trial basis if there is no established standard of care. In fact, I think this is the way to go!

    However, my concern is that this treatment protocol is not being advertised as a trial for a novel therapy, but rather a well understood process (a hidden secret to the concussion world)…and this just is not true.

    No logical, evidence oriented person will fault a Carrick for trying a low risk alterative treatment which as a strong theoretical basis- so why pretend it’s something more?

  4. @Sean: Thanks for the comment; I couldn’t have put it better myself. What I object to isn’t trying “unproven” therapies — it’s representing them as well-established that bothers me. In fact, this is similar to the ongoing debate about barefoot running — I think it’s a great development, but I get tired of the baseless assertions that it’s been “proven” to be unquestionably the right way to run.

  5. Very good point about athletes, though I would say not only ones who are risking millions of dollars. Those of us in far lower-paying sports have just as much, some might say more, drive to win. And it is very difficult to really know what supplements, for example, actually help and what do not. Unfortunately, waiting for proper evidence likely means you are way behind. As someone who strongly believes in being logical this is a quandary.

  6. I am a chiropractic neurologist board-certified since 1992. I have studied under Dr. Frederick Carrick since 1989. I have attended postgraduate courses in this vestibular rehab at the University of Connecticut. These courses have included all aspects of vestibular neurology. These postgraduate courses are attended by medical doctors, PhD’s, chiropractors and other people involved in the stability rehab. Chiropractic neurology is a subspecialty postgraduate degree that requires 3+ years more training after obtaining a chiropractic degree. It also requires a stringent board examination and continued education to remain board-certified. Dr. Carrick is not performing voodoo or something outside of the realm of standard rehab. He is just using the tools available and basic scientific neurological facts and evidence and applying it to patients. Dr. Carrick has a five-year waiting list of coma patients waiting for his techniques to see if they can be helped. I recommend that you get the PBS special waking the brain on Dr. Carrick techniques with these coma patients. Dr. Carrick is also a world-renowned expert on Vincent Van Gough, and his inner ear disease which was manifested through his paintings.
    Sidney Crosby’s return to playing is testament to applications of functional neurology.
    John P Schaefer DC, DABCN
    Prof. Palmer College of chiropractic Florida

  7. From the SI article:

    “The world of chiropractic neurology is largely self-contained and exceedingly self-referential. But follow the threads of its literature or the bona fides of its practitioners far enough, and one thing becomes clear: Everything connects to Ted Carrick. He graduated from Canadian Memorial Chiropractic College in Toronto in 1979. A year later he founded the Carrick Institute for Graduate Studies, which is now headquartered in Cape Canaveral, Fla. There are more than 300 active chiropractic neurologists in the U.S., many of whom have been trained by Carrick.

    Through satellite locations, Carrick and the faculty at his institute lecture to more than 4,000 students in the U.S. and in 10 foreign countries. His is one of three institutes in North America with an accredited chiropractic neurology program; all three were designed by Carrick, according to Harman. (She is now executive director of the American Chiropractic Neurology Board, the field’s certifying body, which she runs from her duplex in Texas, the only state she knows of where a board of chiropractic examiners has formally approved chiropractic neurology as a specialty group.) The body that accredits educational programs in chiropractic neurology is the Commission for Accreditation of Graduate Education in Neurology, whose chairman, Pennsylvania chiropractor Michael Swank, studied under Carrick and says he was appointed by Carrick.”

  8. @Griff: Thanks for the link — that is a VERY interesting article. I highly recommend that anyone interested in this topic check it out.

  9. Dr. Harriet Hall’s experience with Carrick is well worth reading about. While not strictly relevant to his claims, Carrick’s shrill reaction to criticism is damning: extreme defensiveness and legal threats. Questioning of a testable claim in health care is never even unreasonable, let alone libellous. If Carrick can’t take the scientific heat, he should get out of the health care kitchen.

  10. Sidney Crosby’s return to playing is testament to applications of functional neurology.
    John P Schaefer DC, DABCN
    Prof. Palmer College of chiropractic Florida

    Well, Sydney just announced that he’s out indefinitely again, owing to a return of symptoms. If his return is a testament(it’s anecdotal), then this is testament as well.

    It didn’t work.

  11. Being a scientist at heart working in marketing (in health care no less) this episode reinforces my opinion of chiropractic as quackery with great marketing. I’ll believe it when the field can objectively demonstrate any reliable effectiveness (I too can come up with anecdotal/testimony evidence on anything, and I mean anything you can dream up).

  12. @ mikmik, It’s not that Carricks’ techniques haven’t worked. Changing the way the brain “fires” is not such a simple fix. Take any type of sublaxation or blockage, it may take as many as 50 or 100 times for that particular adjustment to take hold permanantly. That may be to fix a nerve impingement in your wrist. Imagine trying to fix a complex organ like a brain and any trauma to it. I think he will continue to have these back and forth conditions as long as he continues to play hockey. No matter how good a doctor a guy may be, and I’m for Carrick as I regularly see a Dr. who has been one of these guys students for a few years now, he’s not going to be able to prevent people from ever having a concussion. So don’t say his technique doesn’t work because Crosby had another concussion. It’s hockey and this is what happens, especially when you play this sport! Judging by how “I” feel about my health right now compared to how I felt 3 years ago, which is markedly improved, I’d say functional neurology has well founded merits of effectiveness. I’d been to the hospital and seen specialists regarding two specific issues in the past and was disappointed that after years of declining quality of life all while following accepted and antiquated medical protocol to no avail. I don’t know Ted Carrick personally but I’d be willing to bet that if you lined up every person Ted Carrick has ever “seen” in a diagnostic or wellness capacity, that he’d have a very high success rate at achieving significant results for those people.

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