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Chronic Pain Shrinks The Brain

Posted by timothy on from the as-long-as-it-doesn't-touch-my-10-percent dept.

An anonymous reader writes "LiveScience is reporting on a study showing that people with chronic lower back pain have 5 to 11 percent less gray matter than pain-free folks. Its not known for sure why, but the thinking is that neurons just get worn out as the mind deals with the pain."

8 of 60 comments (clear)

  1. Study Problems by sailforsingapore · · Score: 3, Interesting

    I'm inheriently distrustful of these studies, if simply because of the sheer number of flaws that could be present in their design. I remember, in the space of one week last year, hearing three different studies; "Eggs are good for you", "Eggs are bad for you" and finally back to "Eggs are good for you". Without huge problems in the study, they couldn't have come up with such disparate results. Take this with a grain of salt.

    1. Re:Study Problems by NiceGeek · · Score: 4, Funny

      Salt is bad for you.

    2. Re:Study Problems by YouHaveSnail · · Score: 3, Insightful

      Without huge problems in the study, they couldn't have come up with such disparate results.

      Not at all. The study (or studies) may be perfectly valid, and the problem may be that you're trying to draw a conclusion that's so simple it doesn't reflect the truth. Or different people interpret the results of the study differently.

      Taking the egg example, it's pretty clear that eggs are good for you and eggs are bad for you. They're a rich source of protein, but they're high in cholesterol and fat. Same study, same data, two different interpretations of "good."

      You don't need to be "inherently distrustful" of scientific studies, particularly if they really are scientific. A better place for your distrust is in the oversimplified interpretations we get from the media, which likes to boil things down to a third grade reading level, and from people and corporations with a vested interest in the interpretation who twist data to suit their own agendas.

  2. In soviet russia... by nerd256 · · Score: 3, Funny

    Shrinking grey matter causes chronic pain

    Seriously, how do we know what the dependent variable is.

    (and the flaming ensues)

  3. Obviously. by Elwood+P+Dowd · · Score: 4, Funny

    "Its not known for sure why, but the thinking is that neurons just get worn out as the mind deals with the pain."

    Right. Either that or being stupid hurts.

    --

    There are no trails. There are no trees out here.
  4. Re:Hahaha I totally read that wrong. by Neon+Spiral+Injector · · Score: 3, Funny

    It just shrinks the short term memory. Like when you can't remember that you opened a bold tag only four words ago.

  5. /.'s Chronic Problems with Causality by Lord+Byron+II · · Score: 4, Insightful
    It is unfortunately a common occurrence here that causality is implied in the stories. This story implies that chronic pain causes the brain to shrink, however the article only links lessor amounts of gray matter with greater amounts of pain.

    Possible causes? Perhaps the pain does cause the brain to shrink. Perhaps people who are predisposed to pain are also born with smaller brains. Perhaps their brains shrunk due to another cause and the shrinkage is causing the pain. Or perhaps with such a small study (26 people) they happened to choose people who just happened to have smaller amount of gray matter.

    I would also like to note that brain functions that make humans able to reason more effectively are located in the gray matter part of the brain, which is the region that was found to be reduced. However, it is also known that the amount of gray matter is not strongly correlated with intelligence. (Actually, it has been found that the amount of folding, that is the number of creases on the brain, affects intelligence much more.) So, there is no reason yet to think that these people are actually suffering any loss of function.

    So while interesting, until more research is done, these results should not be over-interpreted.

  6. suspect statistics by mopomi · · Score: 3, Interesting
    As a chronic back pain sufferer, this article was of interest to me. So, instead of just reading the posted link, I found the actual article.
    Most of the method that others are complaining about (only 26 people, etc.--read the article, they're doing things just fine) seems fine to me, but what really bothers me is this:


    Skull-normalized whole-brain neocortical gray matter volume (excluding the cerebellum, deep gray matter, and brainstem; SIENAX analysis) was 528 +- 44 cm^3 (mean SD; n 26) in the CBP brain and 559 +- 42 cm^3 (n 26) in controls, matched for
    age, sex, and scan type (Fig. 1 A). The 30 cm^3 difference in gray matter volume, a 5.4% decrease, was highly significant (paired t test=3.7; p less than .001). A similar measure was derived from the VBM regional analysis: whole-brain mean gray matter density per voxel (VBM modulation analysis). This measure showed a 5.9% decrease in overall gray matter density (0.251 +- 0.031 in CBP subjects; 0.267 +- 0.027 in controls;



    They're claiming that a 30 cm^3 decrease is significant when their 1 sigma error is 42-44 cm^3! 1 sigma! In my field of science, nobody believes you unless the error bars don't overlap (much) with two or three sigma. Basically, everything is essentially the same to within one sigma:
    528+44=572>569;
    569-42=527528.

    Anyway, I'm sure there's some stuff that I missed, but until a larger study is done with better error analysis, I'll take what they've done as probably correct, but with some doubt. . .