Discussion in 'BioMedical ME/CFS Research' started by Andy, Jul 17, 2020.
Open access, https://www.frontiersin.org/articles/10.3389/fnins.2020.00688/full
It would have been interesting to track function over a longer time period
So previous studies showed patients test performance declined during a head up tilt table test as the angle increased. This study tested before and within 5 minutes after the tilt table. Not surprisingly, the effect of the tilt table persisted during those 5 minutes. The conclusion seems to imply a much longer effect.
I wonder whether they have tested people with ME repeating the test without a tilt table. Cognitive fatiguability may lead to decline in performance on repetition of a cognitive task even without the additional orthostatic effects.
I thought this was an interesting study.
Among the limitations the authors noted are some significant ones:
Interesting study that throws up more questions than it answers. Real pity they didn't retest after a few hours or the next day.
I don't think the fact that they found impaired working memory just minutes after the HUT allows for the conclusion that this impairment is due to early PEM. It may just be that the brain needs a few minutes to recover from the reduced blood flow during the HUT and that a measurement 20 minutes later would have shown nothing.
To be clear, I wouldn't be at all surprised if orthostatic stress caused PEM - I rather suspect it does - it's just that this study doesn't show it because it only tested straight after the HUT.
Does anyone ever write to the corresponding author to point out how a study could be improved?
From personal experience of a tilt table test:
“Despite the (Consultant’s letter saying I "was well on leaving", my 86 yo mother had to escort me out to father's car. I had been unable to speak to her for 5-10 mins when out from the tilt table test & still could not speak properly/word find for at least an hour afterwards. I had many symptoms whilst on the table (see letter in file) and yet Consultant found 'dysautonomia is not the cause of her symptoms'. “
I can confirm PEM started immediately (within minutes of the tilt) and continued, in varying degrees, for many days afterwards.
Are you referring to cognitive PEM?
I would have to look at my notes from the time, but I was extremely thirsty, had to hold the nurse’s arm to go back to the waiting room and was monosyllabic whilst I sat in the waiting room. I just wanted to go home, but needed to wait until I could stand and walk to the exit with mum.
As soon as we reached their home (30-40 mins after tilt ended), I went to bed and was still struggling to speak a complete sentence after a couple of hours.
Separate names with a comma.