Friday, 18 May 2018

Your brain stiffens

Rheology is the study of the flow of matter

An interesting brain fact if you are interested

Magnetic Resonance Elastography (MRE) is a developing technology for quantitatively assessing the mechanical properties of tissue. The technology may be considered to be an imaging-based counterpart to palpation, commonly used by physicians to diagnose and characterize diseases.

Apparently brain stiffness decreases one percent per year during normal aging, so our brains are turning to mush as we get older and MS does not help this. Interestingly they find that when you die, just like your muscle stiffen you get rigor mortis of the brain too and your brain stiffens. 

So we should all use MRI to look at brains and be cautious with histology, is a conclusion.


Weickenmeier J, Kurt M, Ozkaya E, de Rooij R, Ovaert TC, Ehman RL, Butts Pauly K, Kuhl E. Brain stiffens post mortem. J Mech Behav Biomed Mater. 2018;84:88-98.


Alterations in brain  are increasingly recognized as a diagnostic marker for various neurological conditions. Magnetic resonance elastography now allows us to assess brain rheology repeatably, reproducibly, and non-invasively in vivo. Recent elastography studies suggest that brain stiffness decreases one percent per year during normal aging, and is significantly reduced in Alzheimer's disease and multiple sclerosis. While existing studies successfully compare brain stiffnesses across different populations, they fail to provide insight into changes within the same brain. Here we characterize rheological alterations in one and the same brain under extreme metabolic changes: alive and dead. Strikingly, the storage and loss moduli of the cerebrum increased by 26% and 60% within only three minutes post mortem and continued to increase by 40% and 103% within 45 minutes. Immediate post mortem stiffening displayed pronounced regional variations; it was largest in the corpus callosum and smallest in the brainstem. We postulate that post mortem stiffening is a manifestation of alterations in polarization, oxidation, perfusion, and metabolism immediately after death. Our results suggest that the stiffness of our brain-unlike any other organ-is a dynamic property that is highly sensitive to the metabolic environment. Our findings emphasize the importance of characterizing brain tissue in vivo and question the relevance of ex vivo brain tissue testing as a whole. Knowing the true stiffness of the living brain has important consequences in diagnosing neurological conditions, planning neurosurgical procedures, and modeling the brain's response to high impact loading.

I think questioning the relevance of ex vivo brain testing (i.e. not testing in life) as a whole, based on brain stiffness, is rather dubious. We should and can question the value and merits to these techniques but they should not be discarded.

When I started MS research, I was constantly told MS is a white matter condition. Here is an MS brain


You can all see the white matter (dark blue) lesions (within the green circle), but look and you can see relative lack of myelin loss in the grey matter  but you can see areas where there is less myelin (within the red circles).These are probably Grey matter lesions. You just have to look with an open mind.

6 comments:

  1. Does this happen only when you're not on a dmt? Does being on high efficacy drugs like Tysabri prevent these things from happening? I know they stop lesions but do they stop this and brain atrophy?

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    Replies
    1. " Does being on high efficacy drugs like Tysabri prevent these things from happening? "

      Tysabri prevents bad stuff getting into the brain..but it doesn't
      act directly on the brain to protect/fix it.

      Delete
  2. Question yourself on how many MS patients know more about MS than you do. Answer is they have the disease and you don't . MSers are the experts .

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    Replies
    1. Yes pwMS are the experts.
      "They have the disease any you don't"

      Do you know that?
      We could do
      we have worked with people with MS and who knows what is round the corner.

      Delete
    2. I would like to point out something that is not related with the topic of this blog post, but related with the way your last comment was written (MouseDoctor).

      I have been following the blog for quite some time, and have noticed that he majority of the replies to comments are written in broken English.

      May I ask what is the reason for that?
      I can’t help that think that if someone is on a high level of education, they would at least be able to write coherent sentences in English, even if the latter is not their first language.
      It just doesn’t help with credibility if 90% of what you write is full of syntax/grammar mistakes.

      Delete
  3. I am afraid that I am going to be unkind to anonymous above and say the thing that, as doctors, of course you could ever say.

    I think the use of the word "expert" to describe the knowing of something through lived experience of it, rather than the knowing of it through scientific knowledge of it is a debasing of the use of that word. There has to be a better way of saying that a person with the disease "knows" about that disease than saying they are an expert.

    When I say things like this I feel a little like the child in the Emperor's New Clothes story and it is one, perhaps the one, aspect of PC that annoys me.

    I had a comparable experience and a recent disability Forum that I attended where a man with cerebral palsy who, much to his credit and braveness in insisting that people try to understand what is speaking, spoke utterly unintelligibly to a packed room full of people who all politely pretended they understood what he was saying. I was sitting next to a young man was aspergers who was saying, quite audibly, "I can't understand a word you're saying" which is the equivalent of saying "the emperor is wearing no clothes"

    I'd say anonymous was stark staring naked at

    ReplyDelete

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