My Tiny Brain

April 15, 2006 10:49 PM

What's the significance of losing ten percent of your grey matter (cerebral atrophy)?

I have a poorly understood disease. Several recent small studies have suggested a cerebral atrophy that consists of about ten percent less grey matter (globally) than controls. One study found loss of grey matter mainly in prefrontal cortex bilaterally. I've managed to find some interesting info about the prefrontal cortex pretty easily. But I'm having trouble finding any info that could put a 10 percent shrinkage of brainage in context for me. There does seem to be a correlation between the perception of cognitive difficulties and brain abnormalities in these studies, and "brain fog" is a common symptom of this illness. But I'm wondering in what other conditions does this atrophy occur, and how severely? And could this cause anything else besides "brain fog?"

And I do realize that three small studies could be very easily discredited in the future. I'm not buggin'.

posted by overanxious ducksqueezer to health & fitness (13 comments total)

Any chance you could tell us the name of the disease in question? I'm sorry I'm not able to offer any more help, but I'd imagine if you were recently diagnosed, you'd be able to speak to a neurologist or psychologist or someone with a bit more understanding on the topic? This (frighteningly) makes me think of Flowers For Algernon's protagonist... I hope it's nothing like that...

I think age could play a significant factor, though I could also see it being something like "after the age of two, it doesn't matter how old or developed your brain is," but then again, I really know nothing of the brain. You've just piqued my curiosity.

Best of luck...
posted by disillusioned at 1:28 AM on April 16, 2006

This would really be ikkyu2's realm of expertise (he's a neurologist).
posted by junesix at 3:09 AM on April 16, 2006

Sorry, the illness is CFS (chronic fatigue syndrome), which up until 5 years ago many doctors didn't believe existed. And many more still have not heard of. And unfortunately, as it stands right now, I'd be laughed out of a neurologist's office if I went to discuss my cognitive dificulties. Or that's what my former GP told me, anyway.

I made my question too open-ended. What I really want to know is what is specifically known about a ten percent reduction. Is it a big deal, or not even noticeable many times? Though would also be interested in any personal experiences with this in general.
posted by overanxious ducksqueezer at 6:52 AM on April 16, 2006

i don't think there's going to be a simple answer - the brain isn't homogenous so losing 10% doesn't translate directly to 10% slower or 10% less memory or anything that simple. if i were you'd i'd also try looking for information on the brain "rewriring" to work around difficulties - i have the impression that was assumed not to happen after childhood, but then something recent suggested that wasn't the case. but i can't remember any details.
posted by andrew cooke at 7:03 AM on April 16, 2006

I would expect the official answer to be like what andrew cooke said. There have been too many instances of fully (or almost-fully) functioning people with major portions of their brains missing, damaged, or removed.

What I'd be curious about is if anyone's tried to develop a therapy to accomodate cerebral atrophy. I could see where lots of meditation combined with guided visualization, journaling, etc., where you actively try to dredge up old memories and tie them to recent ones or try to remember all the senses involved or whatnot, could help maintain memories by creating new 'wiring' and reinforcing old wiring.
posted by kimota at 8:36 AM on April 16, 2006

links to studies?
posted by unSane at 9:13 AM on April 16, 2006

From memory, but I believe that Basant Puri has claimed that a decrease in brain size can also be associated with depression, and that supplementation with EPA (found in fish oil) can reverse this increase. He also recommends a nutritional approach including EPA for treating CFS. I can't vouch for the effectiveness of any of this but it is something you could look into.
posted by teleskiving at 11:06 AM on April 16, 2006

I have no idea what the clinical/neurological answer is to your question but my first thought was that if you have a 10% reduction in the prefrontal cortex then the implications may be what ever you may or may not be experiencing. Have you experienced any significant shift in thought processes, thinking, perception, executive function. moral ordering etc. If you have a 10% change then the change is in place and operatinal--do others report a difference or do you experience any differences?
posted by rmhsinc at 11:23 AM on April 16, 2006

As you probably already know, Pubmed is a great resource for looking for abstracts of scientific studies. It is also a great place for someone with slight tendencies toward hypochondria and a surplus of time to obsess over the implications of something their doctor has told them (I speak from personal experience here.)

I dont mean in any way by the last statement to slight your experiences with the disease in the least-- on the contrary, I offer my sympathies in what must be a difficult time for you. It seems to me from a cursory going-over of the literature that CFS is not well understood right now. Trying to predict exactly what the progression of your symptoms will be may amount to an uncertain guess at best. Im not sure how psychologically healthy it would be to construct a list of symptoms of cognitive decline, and to be constantly on the watch for any of them in your everyday life.

From what I read quickly, it seems the debate as to whether CFS is a disease or not does not so much revolve around whether people with CFS are complaining a lot, or just on the lower end of a normal scale of a spectrum of activity and energy. It seems more to speak to the fact that CFS is defined right now by a collection of symptoms (some of which do not need to be present for a dx) and not defined by a singular underlying cause. This is a perfectly satisfactory state for the purposes of making a diagnosis, but not for developing a drug target or other treatment.

Brain morphometry is a new and exciting field, (and getting close to what I do for a living-- functional brain imaging) but it is not strictly necessary to validate any psychiatric illness. I managed to find one good study on morphometry and CFS, indicating a 10% overall difference in thickness. Interestingly, regressions against age show the difference between patients and controls as starting very small, and widening (suggesting a decrease in cortical thickness, as opposed to suggesting that a preexisting decreased thickness of cortex leads to increased likelihood of CFS). Also, a second graph shows greater physical activity correlating with more gray matter.

This study breaks CFS down into sub-populations, each of which have a better-defined subset of symptoms and outcomes than the group as a whole, as well as suggesting distinct general causes for each sub-population. If these results hold up in more studies, then this line of research may become critical in establishing CFS as several related diseases.

Also, another study looks at cortical glucose metabolism, and manages to find more regionally specific patterns of decreased activity. Furthermore, the within-subject design allowed the researchers to determine that the disease does not affect all of the patients in the same way.

To get back to the original question you asked, unipolar depression, OCD, PTSD, age-related dementia, normal aging, and Alzheimers are all associated with reduced gray matter volume. These conditions are as different as night and day. Generalizing from atrophy to prognosis is not nearly as helpful as one might think. And finally, anecdotally, there was a case of an undergraduate from an elite university in England (possibly Sheffield, IIRC) being run as a "normal" control in an imaging study. He was found to have an undiagnosed case of hydrocephalus, and due to CSF pressure, his cortical matter was only 10-20% of the thickness it should have been.
posted by Maxwell_Smart at 11:36 AM on April 16, 2006

It sounds to me like the original poster has CFS, and has read that folks with CFS may also have loss of grey matter; but it appears that the original poster didn't get a quantitative brain scan him- or her-self. But you did read some studies, right?

I think that these studies are not meant to be directly applicable or useful to the individual person who suffers from the illness. CFS, or CFIDS as some researchers call it, is very interesting; but I suppose it will come as no surprise if I say that it is a very poorly understood [illness/set of illnesses/syndrome]. Studies like this are fishing, trying to see if anything useful can be learned about the pathophysiology that might shed a little light on the etiology. But I'm not sure that they actually do shed any light.

Global brain atrophy of 10% on imaging studies is a pretty soft finding. I would not expect it to necessarily be correlated to any measurable decline in cognitive function; this was surprising to me when I first learned of it, but in fact I have seen people walking around and doing their daily business with 50-60% brain atrophy. How? I don't know, but they do.

Like so many things in neurology and medicine, the state of affairs is deeply unsatisfying to folks like us who want understanding.
posted by ikkyu2 at 11:38 AM on April 16, 2006

I can't find the actual study, here are two articles discussing them.

Thanks for all the great answers so far.
posted by overanxious ducksqueezer at 12:24 PM on April 16, 2006

The actual study referred to in your two articles may be found here. Google scholar is great at finding versions of academic papers that are not made freely available by the actual medical journal.
posted by Maxwell_Smart at 12:37 PM on April 16, 2006

remember that it isn't clear what the causal relationship is, ie, an inactive/depressive lifestyle could lead to atrophy just as much as atrophy could lead to an inactive/depressive life - and things can get caught in feedback loops, so that if you stop getting enough sunlight/ oxygen / exercise/ vitamins/ social interaction/ (whatever), this could theoretically lead to feeling slower or more depressed or tired, and that could cause the brain to reflect that, which could make you feel worse - etc.

Not to suggest that there may not be a physical start to the whole thing either - just to keep in mind that the mental and physical parts of the brain cause each other. it's a bit of a chicken/egg problem, and worth fighting it from both directions (like, trying yoga, doing extra reading, yadda yadda, alongside whatever your dr is recommending)
posted by mdn at 7:10 PM on April 16, 2006