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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."

2 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.

  2. 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. . .