Slashdot Mirror
MRI Magnets Cause Nystagmus
Hitting the main page for the first time, tibit writes "In an interesting twist on 'it's so old it's new again,' Johns Hopkins researchers led by Dale Roberts found what must have been causing much confusion for doctors the world over: strong external magnetic fields can stimulate the semicircular canals, causing vertigo and nystagmus (pendular eye motion). It's a textbook case of the Lorentz force in action: our angular rate gyros, the semicircular canals in the middle ear, filled with endolymph, have a ionic current flowing across. In a magnetic field, the current produces a force that pushes the lymph along the channel, causing stimulation of the cupula — a pressure sensor at the end of the channel. This is interpreted by the brain as rotation of the head in space, and causes a nystagmus that's supposed to stabilize the image on the retina. Of course, the subject is laying down and not spinning in space, and the mismatch between inertial measurements coming from the ear and the real situation causes vertigo."
We have MRIs at work, I get that Just-Stepped-Off-A-Roller-Coaster dizziness when moving through the field, the effect is well known.
Old news or am I missing something?
Trolling is a art,
Anyone who works around MRI magnets has known this for years. When I was a graduate student, you would always hear stories about people moving their hear around the end of the magnet (where the field gradient is highest) and making themselves dizzy.
Fucking magnets - how do they work?
Radio Wave Propogation too.
Outside of EMF and RF, scar tissue and acidosis is the verry location where most cancer forms. This would explain why Cell Phones and other phenomenons are LINKED to cancer but they don't cause cancer but simply impede the Immune System long enough that a culture of pathogen can increase it's generations to adapt and grow into the body while the Immune System is dysfunctional.
The fluid in your inner ear is not "living tissue". So you miss again.
Nope. There's even some cool experiments involving magnetic manipulation of the brain. Check out the God Helmet (of course, there's some controversy over this one and it looks like sketchy science, but I think it still demonstrates that EM fields can have biological effects).
Conscience is the inner voice which warns us that someone may be looking.
The rapid eye movement, looking from side to side, peeking under things, etc. while out geocaching near guardrails.
A feeling of having made the same mistake before: Deja Foobar
This is a classical example of how you just have to take the time to read the paper and think about it because the cited text and other sources that are not behind pay-wall are just not clear enough.
I have had put my head in number of MR scanners, with field strengths of 0.3T, 0.5T, 1T, 1.5T, 2T, 3T, and 7T, with no nistagmus, but that simply does not mean anything in context of this paper.
You should have in mind that the maximum magnetic field gradients, and their speed are regulated by law.
Interesting question that this paper is offering: are functional-MRI results sometimes tainted by effects of magnetic field gradient while the person is placed inside the device?
Doing a good job is like spilling coffee on a dark suit, you feel warm all over, but nobody notices.
...to explain the eye rolling when people read the bill for the MRI.
I thought magnetic fields had no effect on living tissue?
Magnetic fields don't have the effects you and the horseshit magnetic healing bracelets and EM-"sensitives" claim it has.
It might be easy to mistake that for "no effect under any circumstance" when you're already not worrying about reality.
The enemies of Democracy are
If magnetic fields had no effect on living tissue, MRI's wouldn't work. The biologists and engineers you speak of are saying magnetic fields don't have permanent negative effects. This is about as permanent as spinning around in a chair for 10 seconds and getting dizzy.
In this situation given that it's known that powerful magnets can impact the brain, it's quite telling that you seem to know at precisely what power that no longer is a concern. http://en.wikipedia.org/wiki/Magnetic_seizure_therapy
But, of course it's obviously bullshit because everybody is equally sensitive to everything else.
I have BPPV so I get dizzy pretty easily but after at least twenty MRIs I've never felt anything other than claustrophobia. I wonder if you have to go in head first to get the effect.
You're fucking stupid and you can't type, either (equably, lol).
Biologists and engineers know that sufficiently large magnetic fields can affect living tissue. There are YouTube videos of living frogs levitating inside a 10T bore.
Biologists and engineers ALSO acknowledge that RF has an effect on living tissue. This effect is otherwise known as "heat".
:(){
It's telling you use the bullshit argument of not knowing "precisely" where sensitivity ends when we're talking about effects that are orders of magnitude apart.
Of course I'll happily change my tune when someone can demonstrate a measurable effect on the body from a magnetic bracelet (why not headbands since it's the brain that is known to be affected?), or sensitivity to a Wi-fi router or cell phone tower in a double-blind study. So far such studies have shown no effect, ergo its bullshit.
But you're right -- surely not everyone is equally sensitive. Maybe by some coincidence everyone who thinks they're more sensitive turns actually turns out to be less sensitive!
The enemies of Democracy are
MRI subjects are often lying down, but I don't know what they would be laying down.
No. Don't confuse the issue with the infinite loop of logic. It effects a liquid. Plain and simple. How the surrounding tissue and brain uses that liquid to interpret visuals is entirely irrelevant.
Wood is matter. Does wood react to magnetic fields? Just because the body is made from matter, does not mean that anything can affect it.
Just to be clear, I do not say that magnetic fields do not affect the ear, I'm just saying that the fact that the body is matter does not mean it automatically does.
Whenever in an argument, remember this.
A quick note to tibit, the submitter, to say nice summary. No hyperbole, no outrageous barely marginable links to another agenda, a suggestion, mechanism and evidence. I really enjoyed it, a bit of my brain went "Really? Oh? Like that? Oh that's quite clever, I see what happened there."
You know, it actually makes me want to go and read the article. I think I will. Nice one. More weirdly interesting stuff like this please. Off-topic in many ways, sorry. If it makes up for it, I learned to look for nystagmus when working as a bartender. There's a fairly strong correlation between BAC and the degree of nystagmus in a drunk person as they follow an object with their eyes. You can use this to judge how drunk a person is fairly accurately. In the "controlled circumstances" of me asking off-duty colleagues and friends to follow a finger for ten seconds I could usually work out how much they'd had to drink to the nearest 10ml of alcohol (1/2 pint or a shot of whisky in the UK).
Please consider this account deleted, I just can't be bothered with the spam anymore.
So, water is a living tissue?
Freud might say that Intelligent Design is religion's ID.
Years ago I participated in a paid research study as part of the control group. Part of the research was having an MRI done. After being in the MRI for a short period of time I had the oddest sense of vertigo, despite staying perfectly still. I asked the technician about this, and he brushed it off like it didn't happen, or I imagined it. I was sure he was just wrong, and went home and did my own research. I recall finding some people who had the same experience, but no real idea what the mechanism was. It's fascinating that years later, I have an explanation of what I felt dizzy in the MRI. (Interestinginly, it seemed to persist for a half hour after leaving the MRI).
AccountKiller
To clarify, giant magnets can temporarily induce nystagmus if you move around too quickly in their magnetic field. The nystagmus goes away when you leave. MRI machines cause nystagmus like wearing your winter coat in a sauna causes a fever.
It affects a liquid. It doesn't effect (create in this instance) a liquid.
There is a burden of proof on those that have it to prove it from a technical stand point. However your conclusion that because there isn't a lot of supporting evidence that it's automatically bullshit isn't really the way that it works either.
There's plenty of things that are only recently being uncovered to suggest that those of us that have a very real and very consistent negative reaction to things like a wall of TVs is patently absurd though. If you've got 12 TVs on a wall, that's not a small amount of radiation to be dealing with. Especially if those particular devices are of low quality and poorly shielded. Personally, I'm satisfied that the effect is real from the years where I could consistently identify which TVs were on and which were off based upon which ones gave me a head ache.
I do concede that it's unlikely to the max that a small magnet is going to have much of an impact, if any, on ones health. The sorts and amounts of radiation that people are being subjected to on a daily basis hasn't adequately been studied to know precisely where the limits might be for sensitivity.
The fluid doesn't get moved much, just pushed a little bit -- it's a semicircular canal after all, not a full torus. The pressures sensed by the cupola are on the order of probably nanopascals. This is nowhere near a "considerable" force.
A successful API design takes a mixture of software design and pedagogy.
It's on the internet - it must be true!
BTW everyone - the link AC posted is to a guy who is trying to cure cancer with baking powder because he thinks it's a fungus.
Weaselmancer
rediculous.
STATIC magnetic fields don't have much effect on tissue. Changing magnetic fields have an effect on anything that conducts electricity, living tissue included. The effects are well known and the rate at which the magnetic fields in an MRI scanner can change is regulated to avoid causing unwanted nerve stimulation.
You might want to be a little more careful before calling a trained professional narrow-minded or pseudo-educated. Unfortunately your post is the one that comes across that way.
Congratulations. Your creativity is stunning. If you'd turn it to a useful pursuit instead of making up crap to troll Slashdot....
Hit them with the field, and they will fall over (and all their metal objects, teeth, fillings, etc, will get hot or go flying)
Well we have come up with some other fairly crazy treatments that were successful. Hell - penicillin is a decent example. Let's treat infections with mold. On the surface - sure it sounds wacky.
Not that I'm outright supporting this guy's claim but just because it sounds odd doesn't mean it must be false.
Well, even on Slashdot, we can find a recent discussion of how magnetic fields affect the body, specifically blood viscosity in this case:
http://science.slashdot.org/story/11/06/02/185234/Researcher-Claims-Magnets-Can-Affect-Blood-Viscosity
No, he's not a reputiible surgeon, he had his license to practice medicine taken away because his insane treatments were killing people.
See the following link for some real facts:
http://scienceblogs.com/insolence/2008/08/a_fungus_among_us_in_oncology.php
And I have no idea what you're talking about wrt Dr Warburg's cancer research. PH balance has notging to do with it. "the prime cause of cancer is the replacement of the respiration of oxygen in normal body cells by a fermentation of sugar." -- Dr. Otto H. Warburg in Lecture
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
The magnet in question is a MRI magnet, the word "weak" simply does not apply.
True confidence comes not from realising you are as good as your peers, but that your peers are as bad as you are.
Oh god I was waiting for one of these guys to show up.
" We're all a part of the Earth Mother, man. I'm like connected to all life when I breathe So you see it's like the same thing all over man, We're all just breathin'. "
as in- subject perception?
imagine you have the ability to increase and decrease gravity localized to me by 1 percent.
if I'm lying down, and you range gravity from .99 to 1.01 of normal, I may notice something weird.
if I'm doing a straight bike riding on a bumpy road I may not.
on a trampoline, it may well depend on how you time the changes, but I may never notice.
every day http://en.wikipedia.org/wiki/Special:Random
n/t
...
TFA clearly shows that it's indeed the static field that causes this effect :) Of course it doesn't affect living tissue directly, it just so happens there's a liquid plunger with a constant-enough current flowing through it, at the right orientation, inside of our inner ear. This is a very simple kind of an effect, no tinfoil hat required, and no magic either :)
A successful API design takes a mixture of software design and pedagogy.
Agreed. It shouldn't matter.
A successful API design takes a mixture of software design and pedagogy.
Yeah, because high static magnetic fields cause things to get hot. And it's obviously easy to produce them on a large scale, here on Earth. Yee haw.
A successful API design takes a mixture of software design and pedagogy.
Can't tell if trolling or just very, very stupid.
The man that controls magnetism will rule the world, - Dick Tracy, ca 1945
Sadly, you can find a quote for every quacko viewpoint out there.
A successful API design takes a mixture of software design and pedagogy.
So, how long do you think its will take before the effect can be controlled with targeted, lower power magnetic fields to enhance virtual reality systems, from flight simulators to total immersive video games?
Oh, say does that Star-Spangled Banner entwine / The myrtle of Venus with Bacchus's vine?
Being alive and being tissue are two different things.
Sperm is not living tissue either.
H2O is simply a molecule that is incredibly important to the process called life. Whether it is alive or not is not something I have ever heard debated. It may be a component in something that is alive, just as a neutrino might be. But water on its own is not capable of anything that even remotely resembles what is classically called life.
Put simply, being a part, even an important part, of something that is alive does not confer life on the sub-component. Like a tire is part of a car, but is not, nor ever will be a car.
Freud might say that Intelligent Design is religion's ID.