Limbic Perfusion Is Reduced in Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), 2021, Xia Li et al

[Woolie]

Welcome to the forum @hibiscuswahine! (I know you're not exactly new, but this is our first meeting!).

It would be interesting to have neuropsychological testing for the cognitive function in this group especially on attention and working memory (which utilises the ACC). It appears they might look at microvascular changes which will be very interesting.

Yes, in part. A working memory task will engage the ACC (the dorsal ACC, or midcingulate cortex). But ironically, dysfunction within this region does not always lead to a marked performance decrements on these tasks. This is because the ACC isn't directly involved in supporting the cognitive functions necessary for good working memory performance. Rather, its role is much more general - its seems to be critical for allocating resources during challenging cognitive tasks (modulating ANS to enhance overall arousal, blood perfusion).

The most sensitive tests of ACC dysfunction are those that involve some sort of initiative, such as letter, category, and design fluency, the alternate uses test, and also free conversation (number of new propositions offered by the person). Other good tasks are continuous performance tests and boring vigilance tasks (having to listed for tones that only occur every now and then). Tests that offer an incentive for good performance and also quite sensitive (the incentive doesn't improve performance much in patients with ACC damage).

I have some written material on this is you're interested.

 

[hibiscuswahine]

Welcome to the forum @hibiscuswahine! (I know you're not exactly new, but this is our first meeting!)

I have some written material on this is you're interested.

Kia Ora @woolie! Thank you that would be great! I also wonder as this is your specialty, if there is neuropsychological testing on a range of PwME with different illness severity though appreciate there are a lot of problems with criteria and comorbidities, possibly they may do this in their study.

 

[Woolie]

Kia Ora @woolie! Thank you that would be great! I also wonder as this is your specialty, if there is neuropsychological testing on a range of PwME with different illness severity though appreciate there are a lot of problems with criteria and comorbidities, possibly they may do this in their study.

Hi @hibiscuswahine! Just saw you're a kiwi (sounds dumb of me not to realise, but the hibiscus part in your name made me think of much warmer parts of the Pacific...).

I don't know a lot about neuropsychological testing in MECFS, have been meaning to review the literature - I think you just gave me a good reason! I have always wondered if the cognitive problems in MECFS are related to the autonomic problems. Good cognitive function is so dependent on our ability to modulate blood flow appropriately. That idea is also consistent with the variable nature of the cognitive problems - how they become worse after mental or physical exertion. If this is true, then ACC tasks should also be the most sensitive to MECFS - but for different reasons.

 

[Hoopoe]

Hypoperfusion in the ACC can, therefore, lead to impaired monitoring function and cognitive control of the brain. It has been hypothesized that an inability to predict the amount of energy demands for the required performance may underly mental fatigue [43,50]. This implies that the ME/CFS subjects may have an impaired ability to evaluate or adapt to the energy demands to sustain the performance of demanding tasks, which can easily lead to self-rated fatigue.

I found this bit interesting because it's hard to predict, from how my body feels, how long I will be able to sustain an activity. I often feel better and more capable than I really am. This may also be the reason why pacing is hard and must be learned by experience.

 

[Sean]

This may also be the reason why pacing is hard and must be learned by experience.

I am firmly of the view that pacing is an experienced based process. The basic concept can be explained (and even that is problematic). But the details have to be learned the hard way. Patients have to learn by doing. Anybody who claims to be able to teach it is kidding themselves, at best.