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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,
I thought magnetic fields had no effect on living tissue? This is the standard response from the laughably narrow-minded biologists and the equably hilarious pseudo-educated engineers.
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.
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 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 don't doubt the dizziness, but the explanation. The fluid gets moved around because of the current?
Electrical currents in the body are extremely weak. They would not cause heavy fluid to move and excert pressure. If the magnet really can do that, then you'd also feel considerable force due to the nerve impulses in the body - and in the brain. Surely that might cause even more dizziness...
I'm sure that the U.S. government is all over this already.
Never thought I'd put those words together like that.
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.
MRI subjects are often lying down, but I don't know what they would be laying down.
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.
Fire whatever marketing drone came up with the idea that first-time submitters need to be recognized. Its fucking annoying, stop it.
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.
Didn't Steve Martin prove this in the Jerk with the invention of the Opti-Grab?
I got this information from http://cancerisafungus.com/ by a reputable surgeon.
There is also the matter of Dr Warburg's Nobel Prize for his achievement of determining that Cancer and Fungus are linked by the host's bodily substrate PH become acid.
Yet the first response I get is claiming I know nothing about biology? Explain how Pharmaceutical companies kill 4 million per year from resulting infections of surgeries, and over 500 doctors suicide each year from suicidal depression because they can't cure anything? Maybe it's because you want to die, and all you ever learned was in Doctrine form of a University lab not in the field with your own credibility on the line. That's the problem with certifications, is you blame your credentials as being wrong rather than yourself being liable for your fuckups.
"The subject is laying down" - gack! Try "The subject is lying down" instead.
Hit them with the field, and they will fall over (and all their metal objects, teeth, fillings, etc, will get hot or go flying)
Your lack of precision astounds me. It is Sodium Carbonate (without Aluminium) annealed to Maple Syrup, so don't play stupid.
It's fucktards like you that give the practice a bad reputation, and your unjustified fear of competition is discerned in the voracity of your unfounded criticism.
Somone either presents a hypothesis, has field trials, collaborates with fellows of same character, and improves their commerce, or they get a bad reputation and bad statistic like Abbot Laboratories and Merck and Pfizer.
wtf is wrong with you?
All my sources are verifiable.
The truth is funnier than fiction, and the astroturfing you people are doing to my commentary.
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
...
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.
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.
Could the recently reported vision problems in ISS astronauts be related to the stronger magnetic fields out there? Or to nystagmus induced by microgravity?
Sorry if I'm way off, I'm just a layperson.
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?