New Dr Snell paper on exercise and CFS

MeSci

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Amazingly - given the huge issue with fatigability in this illness - no one really seems to have tried. Most studies focusing on patients vs controls without stressing

Rayhan and Baraniuk measured cognitive function after a repeat 2-day exercise test (like Snell) - and found no difference in cognitive performance, though they did find some evidence of different brain activation in GWI patients (who also met CFS criteria) vs controls post-exercise. See this blog. (Cognitive performance was worse in patients, but no different before/after exercise).

A very interesting study in 2011 found that for CFS patients with POTS, cognitive performance was normal when supine but declined with increasing tilt angle. A follow-up study last year found evidence this was due to problems with brain blood flow.

I think the fatigability and PEM with both mental and physical tasks might be unique to ME, and i've always wondered if there was a common mechanism. do hope someone will try to find outl
I'm surprised at Rayhan and Baraniuk's results. Brain fog is part of my PEM. I often get it immediately after exertion too, at the same time as limb aching and weakness. I strongly suspect that lactate is a common causal factor.
 

Firestormm

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I'm surprised at Rayhan and Baraniuk's results. Brain fog is part of my PEM. I often get it immediately after exertion too, at the same time as limb aching and weakness. I strongly suspect that lactate is a common causal factor.
I have yet to check out Simon's links; but for me it has never been about 'intelligence' more about 'speed' and 'duration'. Does that ring true with you? I take far longer responding, answering, processing, interpreting, understanding etc. but for me at least I find it difficult to determine if this is 'worse' after physical exertion or not.

For example: if I am struggling mentally, I will defer that task and do something less cognitive and more physical. I can sometimes return to the mental activity and continue. Outside of a specific 'exercise' test I find it difficult to determine if 'physical' exertion corresponds to greater problems with cognition. Hand on heart I don't believe it does unless it is really excessive and then I'd collapse anyway and retire (or expire :)).

And, you know, we have said this before on this thread (I think) physical exercise is only part of what I think we all understand by PEM. The 'malaise' can apply whether the activity be one of mental or physical excess. My own main and overriding issue is the cognitive side of it because let's face it that was what I relied upon most for my career.

If I try and do too much mentally, I find it very difficult indeed to continue successfully let alone accurately. So I think I would like to see more of the 'mental-exertion' study personally. I believe the physical exertion studies are achieving their objectives nicely. Mental though is particularly subjective I think. Still there have been some initial forays into this using MRI and getting folk to undertake mental tasks.

Can't remember now where they were or what they showed to be honest; card-games wasn't it? I forget :)

I mean 'brain-fog' needs a better explanation. At present I experience mental fatigue - I think that can and is used to encapsulate all our problems: fatigue explains it all. At least in certain quarters :zippit:

So it would be nice - and is nice - to see them getting a better bead on what might be happening biologically. Help break down those barriers - so to speak :)
 

MeSci

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I have yet to check out Simon's links; but for me it has never been about 'intelligence' more about 'speed' and 'duration'. Does that ring true with you? I take far longer responding, answering, processing, interpreting, understanding etc. but for me at least I find it difficult to determine if this is 'worse' after physical exertion or not.
I think it varies with me. Sometimes my thought processes are just very slow, and/or I can't hold one thought, move to another and then come back again, which is why conversation can be difficult and I may seem rude, rushing to say my piece and maybe interrupting someone, because if I don't say it straight away I will completely forget it until hours later or even days later. At other times the best way I can describe it is that thinking is like trying to wade through treacle, or it is like I am in a fog, or like there is a hazy screen between me and the rest of the world - I feel disconnected from it and often can't see things around me properly, which can be due to visual problems and/or cognitive ones (trouble processing/making sense of the visual input).

For example: if I am struggling mentally, I will defer that task and do something less cognitive and more physical. I can sometimes return to the mental activity and continue.
That's a good example of switching, which is a very useful technique in ME. It's also good to switch from using legs to using hands to using eyes, etc., so giving each part of the body a rest for a while.

And, you know, we have said this before on this thread (I think) physical exercise is only part of what I think we all understand by PEM.The 'malaise' can apply whether the activity be one of mental or physical excess.
Agreed.

My own main and overriding issue is the cognitive side of it because let's face it that was what I relied upon most for my career.
Bummer :(
 

urbantravels

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I don't know if they still do this - at the time I was tested it seemed like they were phasing it out - but at the former PFL they had some cognitive testing at the end of the day 2 test. I thought it was a little odd that they didn't do any cognitive testing at the outset to establish a baseline.

The test was not very sophisticated - it was basically hitting letters when you see them come up on screen, repeating sequences of letters that sort of thing - and they sort of played the cognitive testing down to the point where it's barely mentioned in the final report. It was brief, not more than 20 minutes I think, and I didn't show any abnormalities in particular. (But without a baseline, how'd you know if my cognitive abilities had actually declined? My pre-illness baseline was VERY fast recall and reflexes. Huge trivia champion. My non-crashed baseline now is a lot slower. Crashed, I don't think I could even be bothered to try a test. I certainly can't type worth a damn when I'm crashed.)

You'd think I'd have been so crashed at the end of the Day 2 test that I wouldn't be able to sit up at a keyboard at all, but I didn't really get into full crash mode until the second or third day after I got home. The severest crashes I've had have tended to kick in more than 24 hours after the triggering exertion.

I can't identify any crashes I've had *just* from mental exertion. I have had them from extreme emotional upset. But either mental exertion or emotional upset usually don't occur without some physical exertion as well. Emotional upset might involve a lot of sobbing or yelling (not that I've EVER done those things :whistle: ) Sometimes I'll get really involved in writing and thinking something through, and then suddenly realize that I've gone way past my envelope by typing, holding my arms and shoulders and head up, etc. So it's impossible to say how much fatigue I've caused by working my brain and how much by working a keyboard. (I've tried dictation software, but that is fatiguing too, because you can't just murmur at it. You have to project your voice a fair amount and enunciate a lot to get the thing to register your words properly, and correcting mistakes also adds extra work. I get respiratory muscle fatigue pretty quickly from that.)

I really would get a lot more done as a disembodied spirit. Just about everything seems to involve using your body in SOME way, darn it.
 

urbantravels

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At other times the best way I can describe it is that thinking is like trying to wade through treacle, or it is like I am in a fog, or like there is a hazy screen between me and the rest of the world - I feel disconnected from it and often can't see things around me properly, which can be due to visual problems and/or cognitive ones (trouble processing/making sense of the visual input).
Well, we don't have treacle here, but I think I know what you mean. I can't multitask or answer things quickly any more...but what I really notice is how befuddled I get when under sensory overload, or standing up, or both at once. I'm functional enough to go for short errands some days of the week. And I've always been used to shopping without a list, because it's just me and I normally would just remember what I needed. Now, I go to the grocery store, carefully pacing myself slowly walking around, and often get increasingly befuddled and confused, until I'm staring at a display of something and can't even tell what I'm looking at. I have tried to be better about making lists and sticking to them so I don't wander aimlessly - and also have learned to avoid larger, noisier, brighter stores.

ETA: Feeling like the things around you are strangely far away or that sounds have suddenly gotten quieter is a "pre-syncope" symptom - that is, not quite fainting but getting lightheaded and confused. My guess is that it's related to blood flow in the brain and I take it as a signal to SIT DOWN RIGHT NOW.
 

SOC

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ETA: Feeling like the things around you are strangely far away or that sounds have suddenly gotten quieter is a "pre-syncope" symptom - that is, not quite fainting but getting lightheaded and confused. My guess is that it's related to blood flow in the brain and I take it as a signal to SIT DOWN RIGHT NOW.

I wish somebody had told me that about 10 years ago. I tried to describe it to docs for years without any response on their part -- just got their usual "just hypochondria" reaction. Maybe, just maybe, if I'd been able to point out that these were pre-syncope symptoms I wouldn't have been running around a quart low on blood all these years.
 

Shell

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urbantravels and SOC that it's all moving away feeling is my cue to sit down. Also the sudden rise in nausea from nagging to "she's gonna blow".
Fortunately all the kids in our home ed group understand that sometimes I just have to sit down. I grabbed one on Wed, pushed her off her chair mumbling and sat down. She was fine about this as it's just one of those "she has to sit down or fall on us" moments. lol
 

MeSci

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I don't know if they still do this - at the time I was tested it seemed like they were phasing it out - but at the former PFL they had some cognitive testing at the end of the day 2 test. I thought it was a little odd that they didn't do any cognitive testing at the outset to establish a baseline.

The test was not very sophisticated - it was basically hitting letters when you see them come up on screen, repeating sequences of letters that sort of thing - and they sort of played the cognitive testing down to the point where it's barely mentioned in the final report. It was brief, not more than 20 minutes I think, and I didn't show any abnormalities in particular. (But without a baseline, how'd you know if my cognitive abilities had actually declined? My pre-illness baseline was VERY fast recall and reflexes. Huge trivia champion. My non-crashed baseline now is a lot slower. Crashed, I don't think I could even be bothered to try a test. I certainly can't type worth a damn when I'm crashed.)
I am still pretty sharp sometimes. Trouble is, as with the physical ability, I never know when my brain is going to work and when it isn't!

You'd think I'd have been so crashed at the end of the Day 2 test that I wouldn't be able to sit up at a keyboard at all, but I didn't really get into full crash mode until the second or third day after I got home. The severest crashes I've had have tended to kick in more than 24 hours after the triggering exertion.
My PEM used to come like clockwork 24 hours after exertion. Since I started my alkalising diet and supplements, the gap got longer and the PEM got milder, sometimes coming a week later and being very mild (almost unnoticeable) and sometimes apparently not coming at all. :)

I really would get a lot more done as a disembodied spirit. Just about everything seems to involve using your body in SOME way, darn it.
That is so well put - I know just what you mean! So often the spirit is willing and the body just says no. I curse it sometimes - "Stupid $£%&&* body!"
 

MeSci

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Well, we don't have treacle here, but I think I know what you mean. I can't multitask or answer things quickly any more...but what I really notice is how befuddled I get when under sensory overload, or standing up, or both at once. I'm functional enough to go for short errands some days of the week. And I've always been used to shopping without a list, because it's just me and I normally would just remember what I needed. Now, I go to the grocery store, carefully pacing myself slowly walking around, and often get increasingly befuddled and confused, until I'm staring at a display of something and can't even tell what I'm looking at. I have tried to be better about making lists and sticking to them so I don't wander aimlessly - and also have learned to avoid larger, noisier, brighter stores.

ETA: Feeling like the things around you are strangely far away or that sounds have suddenly gotten quieter is a "pre-syncope" symptom - that is, not quite fainting but getting lightheaded and confused. My guess is that it's related to blood flow in the brain and I take it as a signal to SIT DOWN RIGHT NOW.
I think treacle is pretty-much what you call molasses in the US.

My 'far away' feelings have not usually been the pre-syncope type. It's maybe not that easy to tell the difference though. My pre-syncope type (which has been due to low blood salt rather than low blood pressure) has also involved vertigo, and I think things seemed darker.

They can be very inconvenient though. I had one episode when I was about to cross a road. I couldn't see or hear the traffic properly. I think I was fairly sensible about it!
 

SOC

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I think treacle is pretty-much what you call molasses in the US.

My 'far away' feelings have not usually been the pre-syncope type. It's maybe not that easy to tell the difference though. My pre-syncope type (which has been due to low blood salt rather than low blood pressure) has also involved vertigo, and I think things seemed darker.

They can be very inconvenient though. I had one episode when I was about to cross a road. I couldn't see or hear the traffic properly. I think I was fairly sensible about it!
What I would have called pre-syncope is more like that, too. If I get there, I do have to sit/lie down or faint. The other 'far away' kind of thing can continue indefinitely. It's probably still a low blood flow to the brain problem, perhaps just not so acute...?
 

SOC

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urbantravels and SOC that it's all moving away feeling is my cue to sit down. Also the sudden rise in nausea from nagging to "she's gonna blow".
Fortunately all the kids in our home ed group understand that sometimes I just have to sit down. I grabbed one on Wed, pushed her off her chair mumbling and sat down. She was fine about this as it's just one of those "she has to sit down or fall on us" moments. lol
Oh yeah, they get that you have to sit down sometimes, but give them a chance to nag you based on an alarm rather than your sense of yourself and they simply delight in being the boss. :D And that alarm is likely to go off long before that sudden rise in nausea -- while you're still feeling "okay" in my experience. With my group of homeschooled students, there was no telling them I felt fine, I could keep going (which I shouldn't, I finally learned). If that alarm went off, I was laying down with my feet up whether I thought I needed to or not, lol! They were right, of course, and not susceptible to my tendency to push myself a little further, so they made great HR police. In fact, they positively relished it. :D
 

urbantravels

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Funnily enough, although I haven't fainted since contracting ME/CFS, I did have a tendency to faint now and again when I was an adolescent/teenager. Usually had to do with being somewhat dehydrated in hot weather and having to stand a long time. I have no idea if that has any bearing on my present orthostatic intolerance. At the time it seemed to be something I "grew out of" eventually.

My family likes to torture me by reminiscing about the most embarrassing fainting incidents. Of special note was a family friend's wedding when I was about 12. It was very hot, I'd been running around all morning helping with wedding stuff and probably hadn't had enough breakfast, the church was a bit close, the wedding was rather long, and we had to stand for an INTERMINABLE prayer during which I was afraid I would throw up. At last the prayer was over and it was time to head up to the altar rail for communion, at which point I swooned dramatically in front of the whole congregation - and my mother, who is a clergy person and was assisting with the service and helping administer communion, so she had to stay behind the rail while all this was happening. Some people carried me out and flopped me under a tree and brought me water and communion bread and I eventually recovered. (Fortunately this was an earthy crunchy liberal Episcopal church in the 70s, so it was some sort of whole grain bread and not communion wafers.) A good time was had by all.
 

Simon

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I've now blogged on this paper Repeat Test Reveals Dramatic Drop in ME/CFS Exercise Capacity

Here is the full abstract, a part of which I have a (non-significant?) bone to pick with:...

Concerning this statement: "The lack of any significant differences between groups for the first exercise test would appear to support a deconditioning hypothesis for CFS symptoms." I have not read the full-text yet, and I suspect this was just said in passing as a prelude to then contradicting the deconditioning hypothesis, but I do not understand how the lack of any significant differences between the two groups, on objective measurements (1st test), allegedly supports the deconditioning hypothesis? If anything it refutes it, how can CFS symptoms be attributed to deconditioning if non-disabled sedentary individuals with similar levels of fitness do not report such symptoms either before or after exercise?
I don't think this was phrased quite right in the abstract. What the study did find was very low levels of VO2 max despite high levels of exertion, indicating deconditioning by comparison with healthy norms. But the fact that sedentary but healthy controls were also deconditioned is good evidence against deconditioning in my book.
 

Valentijn

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In short, individuals with CFS/ME were unable to reproduce their Day 1 performance on Day 2. The statistical classification analysis points to a diagnostic biomarker for CFS/ME with a 95.1% accuracy.

The study “Discriminative Validity of Metabolic and Workload Measurements to Identify Individuals with Chronic Fatigue Syndrome” was published on June 27th in the Physical Therapy Journal (PTJ). The statistical analysis correctly classified 49 of 51 CFS/ME patients and 9 of 10 matched, non-disabled, sedentary individuals based on 2 day CPET.
That's pretty damned good.