Full title: Exercise alters brain activation in Gulf War Illness and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome https://academic.oup.com/braincomms/article/2/2/fcaa070/5885074 The Science Times covers the story here: https://www.sciencetimes.com/articl...-war-illness-distinguished-brain-activity.htm Also: https://medicalxpress.com/news/2020...udy of,brain activity after moderate exercise. A similar study by the same authors discussed here: https://www.s4me.info/threads/exerc...gulf-war-illness-2020-washington-et-al.13542/
"If confirmed, then deep brain stimulation of the midbrain, or transcranial direct current stimulation or magnetic stimulation of cerebral cortical regions may be considered as therapeutic options for ME/CFS and GWI in the future" - I just have to chuckle at this. It reminds me of something you would be tempted to write in the conclusions-part at uni, when u have no idea what else to say. I remember getting top grades at an experiment review, where I knew all the things i was citing was pure speculation and none of the authors cited really knew what the evidence behind the terminology they had made was. Not to take anything away from these guys though, I just dont see how deep brain stimulation is gonna magically fix ME/CFS
Hmm, looks like something that the BPSers will love to see. Of course, the little detail about whether these changes are cause or effect of ME will be important.
I do like the idea of using sub-maximal exercise and measuring pre/post differences in brain function during a cognitive challenge. The sample size was big by the standards of fMRI studies (38 ME/CFS; 80 GWI, 31 Healthy) but still small. I'm not sure that the sub-maximal test, based on 25 minutes at 75% age-predicted max heart-rate, is equivalent for GWI & ME/CFS (SF36 physical function c45) vs healthy controls (SF36=85). It was likely to be much harder for the sick groups. That said the differences for GWI & ME/CFS are often in opposite directions, but at the results for one of the groups could be down to higher exercise intensity. Authors have no place suggesting treatment without replication. And that. I think we need to see a replication before there is any grounds for talking about therapeutic approaches . BTW, this group has used fMRI (single day, no exercise challenge) to find differences between ME/CFS and controls (and GWI, I think). I don't ever recall seeing that one replicated.
So, wouldn't this actually then be a biomarker for both ME/CFS and GWI? ...or might be if the CFS recruitment criteria wasn't just Fukuda.
Lots of potential for bias with fMRI studies Variability in the analysis of a single neuroimaging dataset by many teams, 2019, Botvinik-Nezer et al The paper says nothing about any effort to control for 'time of day' variance. Fukuda criteria, Chalder Fatigue questionnaire used - surely Baraniuk knows better than that? There's a big difference in the gender percentages of the ME/CFS group compared to the other two groups. There's also a difference in BMI. Together those two differences might result in some systematic error in spatial assumptions about regions of interest (ROI) in the brain. Corrections were made for age and gender, but such corrections can be a source of error when the sample populations are different. There are enormous differences in the incidence of 'major depression' (0% health controls; 18% ME/CFS; 50% GWI), with PTSD having a similar range of incidence. Different co-morbidities are likely to confuse any comparisons. Edit - having got to the end of the paper, I see the authors acknowledge this: Potential problems aside, the findings in the discussion look worth picking through, and I agree with Simon that pre and post-exercise studies with a cognitive challenge are a good approach to fMRI studies. It would be good to see future studies record levels of perceived pain/bodily discomfort during the scans and look for associations between that and the results. And for some analysis of the impact of major depression on results (i.e. did having major depression explain results better than the GWI/MECFS split?)
The study is maybe as interesting as much for the differences it didn't find as what it did find. So is BOLD just a contrast signal - it doesn't tell us about the absolute level of blood oxygenation? I don't know how long the cognitive task was for; it would be interesting to see what would happen if the task was for a relatively long time. Also, of course the scanning was done lying down - so it misses the impact of being upright on cognitive tasks.
