The study is Diffusion tensor imaging of the hippocampus and verbal memory performance: The RUN DMC Study, and it actually has nothing to do with hip-hop, but it does have one of the best study acronyms I have ever seen.RUN DMC stands for the "Radboud University Nijmegen Diffusion tensor and Magnetic resonance imaging Cohort study".
Or maybe it does relate to rapping. Because the paper is about verbal memory, and if there's one thing a rapper needs, it's a good memory for words, otherwise they'd forget their lyrics and... OK no, it doesn't relate to hip-hop.
It is however a very nice piece of research. They took no fewer than 503 elderly people - making this by far the single biggest neuroimaging study I have ever read. They used DTI to measure the quality of white-matter tracts in the brain and correlated this with verbal memory function. DTI is an extremely clever technique which allows you to measure the integrity of white matter pathways.
The theory behind the study is that in elderly people, white matter often shows degeneration. This is thought to be caused by vascular disease - problems with the blood flow to the brain, such as cerebral small-vessel disease which means, essentially, a series of mild strokes, which often go unnoticed at the time, but they build up to cause brain damage, specifically white matter disruption.
The symptoms of this are extremely varied and can range from cognitive and memory impairment, to depression, to motor problems (clumsiness), all depending on where in the brain it happens.
All of the people in this study had cerebral small-vessel disease as defined on the basis of symptoms and the presence of visible white matter lesions on the basic MRI scan. The authors found that the integrity of the white matter tracts in the area of the hippocampus, as measured with DTI, correlated with performance on a simple word learning task:
The healthier the hippocampal white matter, the better people did on the task. This makes sense as the hippocampus is a well known memory centre. This is only a correlation, and doesn't prove that the hippocampal damage caused the memory problems, but it seems entirely plausible. The authors controlled for things like age, gender, and the size of the hippocampus, as far as possible.
Should we all be worried about our white matter when we get older? Quite possibly - but luckily, the risk factors for vascular disease are quite well understood, and many of them are things you can change by having a healthy lifestyle.
Smoking is bad news, as are hypertension (high blood pressure), obesity, and high cholesterol. Diabetes is also a risk factor. So you should quit smoking, eat well, and ensure that you're getting tested and if necessary treated for hypertension and diabetes. All of which, of course, is a good idea from the point of view of general health as well.
van Norden AG, de Laat KF, Fick I, van Uden IW, van Oudheusden LJ, Gons RA, Norris DG, Zwiers MP, Kessels RP, & de Leeuw FE (2011). Diffusion tensor imaging of the hippocampus and verbal memory performance: The RUN DMC Study. Human brain mapping PMID: 21391278
8 comments:
So booze up and eat a lot of VitB? No matter what, in the end you'll end up a drooling vegetable. One can just stretch out the duration of the withering away by lifestyle modification.
Your Expiration Date is pretty much carved in stone. Living beyond that date maybe possible but hardly to be envied.
I propose that there is a mandatory stint of work in a senior care facility for adolescents so they can choose to live the life or crave for something which in the end is pretty awful.
Be careful what you wish for you may end up getting it.
My wife was chef de clinique in such a place. Pretty sad stuff.
That's it - for my next grant application I'm focusing on the acronym.
It's seriously quite important. I got 150 PubCrawler hits yesterday and I decided to download this paper purely on the basis of the title. Granted I only downloaded it to blog about it but still - it gets attention and that's very important.
I have this. Have had it for several years now. Was diagnosed at about 50. Because I did not have any of the contributing factors, I've practically had my genome sequenced to find the cause. It's awful, actually.
Hey there!
Maybe you can help me with an issue I have: I have read a couple of papers that use the concept of measuring "white matter integrity" by examining the Tensor Models derived from the ADC images you get from a DTI scan. In general, it seems that the more prolate the tensor models are (alternatively, higher FA values have been widely used), the more 'white matter integrity'. But to my knowledge we only use the term integrity because you see lower FA values in damaged white matter tracts and higher FA values are associated with better 'performance' in whatever the paper is about.
So what exactly is white matter integrity and why is that what we measure when looking at DTI scan. Is it safe to assume that increased local restriction of water diffusion can so directly be labelled 'integrity'?
I'm sceptical. I'll use DTI scans in an experiment for my thesis soon and I'll also correlate it to a measure of performance, but as for now, I'd feel uncomfortable to use 'white matter integrity' as a term.
What do you think? Did I miss an essential paper explaining the situation?
M.S. I would recommend speaking to your supervisor about this.
Clearly though, this is one of those grey areas in imaging studies. I think it's safe to say that DTI is as good at measuring "integrity" as fMRI is at measuring "activity". In both cases, the commonly used term mis-represents what the measure actually analyzes.
My supervisor also said that to him the situation is unclear. (And he's well versed in this area.) So, I don't really see that this is an issue that has seen the attention it deserves. (Which is my main point.)
I see what you mean.
But in past work, I've also avoided the term activity, but used BOLD terms to describe my results. (ha, ha :)
Has integrity seen similarly hot debates as activity has?
Also: at least 'activity' is rooted in something every living brain has, whereas integrity is something only clinical cases LACK.
MS: I'm afraid I can't really help because I've never used DTI. I doubt it has been debated as extensively as BOLD, though, because it's newer (invented in 1994, compared to 1990 for BOLD, and very uncommon until about 2000).
Plus, whereas the interpretation of BOLD can draw on lots of physiological knowledge about brain blood flow (which goes back decades), the interpretation of DTI is, as far as I can see, a "blank slate" since diffusion of water can only be measured using that technique.
Going back to the early paper from before 2000 might be the best bet. Often the early papers have the most detailed theoretical discussions.
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