The Impact of a Structured Exercise Programme upon Cognitive Function in Chronic Fatigue Syndrome Patients, 2019, Zalewski, Morten, Newton et al

Andy

Andy

Retired committee member
Background: Cognitive function disturbance is a frequently described symptom of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). In this study, the effects of a structured exercise programme (SEP) upon cognitive function in ME/CFS patients was examined.

Methods: Out of the 53 ME/CFS patients initiating SEP 34 (64%) completed the 16 week programme. Cognitive function was assessed using a computerized battery test consisting of a Simple Reaction Time (SRT) (repeated three times) and Choice Reaction Time (CRT) measurements, a Visual Attention Test (VAT) and a Delayed Matching to Sample (DMS) assessment.

Results: Statistically significant improvement was noted in the third attempt to SRT in reaction time for correct answers, p = 0.045, r = 0.24. Moreover, significant improvement was noted in VAT reaction time, number of correct answers and errors committed, p = 0.02, omega = 0.03, p = 0.007, r = 0.34 and p = 0.004, r = 0.35, respectively. Non-significant changes were noted in other cognitive tests.

Conclusions: A substantial number of participants were unwilling or unable to complete the exercise programme. ME/CFS patients able to complete the SEP showed improved visual attention both in terms of reaction time and correctness of responses and processing speed of simple visual stimuli.
Click to expand...
Open access to PDF, https://www.mdpi.com/2076-3425/10/1/4

Note: Fukuda selection criteria.

ETA: I was conflicted whether this should go in the Biomedical or the Psychosocial sub-forum as, to my mind, there are elements of both about it.
 
It is important to acknowledge the significant dropout rate (35 from 69 patients (50.7%)) who following CPET assessment or proceeding initiation of the SEP programme did not complete the programme. This is consistent with other studies where a 50% drop out rate was observed within 6–12 months of starting to exercise regularly [37–39].

Overall, it could be concluded that both acute physical exercise bout and effects of physical exercise programme can lead to cognitive function improvement in many patient populations. However, in the case of ME/CFS patient’s further research on this topic is needed because participation in a physical exercise programme has the potential to induce post-exertional malaise at least in some participants [40].

The high drop-out rate amongst ME/CFS patients in this study with a number of individuals not showing improved cognitive function highlights the need for care in advocating SEP therapy and the potential heterogeneity of this patient group. It is therefore important, that those who are engaging in a structured exercise programme where there might be potential benefits are fully informed of possible detrimental effects with regular contact with the clinical team.

Also research focussing upon risk stratification that allows specific phenotypes who are more likely to benefit from exercise based interventions (and those who are not) is much needed.
Click to expand...

These findings and our results support the idea of the effectiveness of such activity therapies in remediating clinical cognitive status in ME/CFS patients. Our findings warrant further investigation, including replication in a larger sample with proper control group applied but with caveat in that we need to identify potential responders and non-responders before embarking on such programmes
Click to expand...
 
''Sixty nine patients were invited to attend a second day of assessment which consisted of cardiopulmonary exercise testing (CPET) and explanation of the SEP protocol. However, 16 described themselves as unable to undergo CPET because of the anticipated post-exertional malaise symptoms during and after exertion. In total, 53 patients underwent a SEP protocol of 16 weeks. Thirty four 64.2% patients completed the intervention and underwent a follow up assessment that included fatigue, CPET and autonomic nervous system assessments...''

So they started with 69 patients who met Fukuda criteria, but only 34 were able to do the CPET and the exercise program. That sounds to me as though the half who didn't complete were ME patients with PEM, and the other half probably didn't have PEM, so would not have met ME criteria such as IOM, ICC and CCC.

From the discussion:
The main conclusion of our study is that ME/CFS patients who completed a structured exercise programme improved in terms of (i) correctness of responses in visual attention test, (ii) reaction time in visual attention test, (iii) processing speed of simple visual stimuli. However, a number of patients did not improve and none of the effects remained significant after FDR correction.
Click to expand...

(The false discovery rate (FDR) is a method of conceptualizing the rate of type I errors in null hypothesis testing when conducting multiple comparisons. FDR-controlling procedures are designed to control the expected proportion of "discoveries" (rejected null hypotheses) that are false (incorrect rejections).)

So we have a study that claims effectiveness on the basis of a few minor improvements in reaction time in a few patients that are no longer significant when corrected for multiple comparisons. And looking at the graphs, it looks to me like a lot of people actually got worse, but the averages moved in the 'right' direction because of a few outliers.

The abstract is highly misleading.
 
disappointed that K.Morton, J.Newton and EUROMENE are involved in this

eta:
Our SEP protocol is based on the deconditioning and exercise intolerance theories of chronic fatigue syndrome, which could be described as vicious cycle [29]. ME/CFS has been hypothesized to be linked to deconditioning and avoidance of physical activity [29]. Gradual deconditioning eventually leads to an increased effort sensation which leads to an even lower level of physical activity. The aim of SEP is to break this vicious cycle and gradually return the subject to the appropriate level of physical activity level reversing the deconditioning and eventually reducing fatigue and disability [30]. Our SEP is similar to the NICE recommended [14] graded exercise therapy,
Click to expand...

eta2:
However, a number of patients did not improve and none of the effects remained significant after FDR correction.
Click to expand...
 
Last edited:
I'm sorry dear authors but this is a bit hard to believe. I think it's unlikely that you succeeded where others tried for 30 years with far more resources and failed. There is a discrepancy between what this paper seems to suggest (meaningful improvement in ability to exert) and what PACE showed (no increase in fitness, no improvemend on BORG scale, no clinically significant increase in walking speed).

Based on individual CPET results, physiotherapists introduced the patient to a personalised exercise protocol including a demonstration of stretching exercises to be carried out as part of the plan. Home exercise was prescribed at least five days a week, 16 weeks in total, with the initial 3 sessions lasting approximately 10 min. Initially patients were asked to perform training bouts with the intensity of 30–40% of HRmax prescribed individually to patients depending on the CPET result. During the training plan exercise intensity was gradually increased. After the first 3 training sessions, aerobic exercise duration was increased to 20 min with 10% higher intensity in terms of %HRmax; moreover, 3 stretching exercises were added to each training session. Intensity, duration and number of stretching exercises were gradually increased with subjects exercising to between 70–80% of HR max for 40 min with an additional 7 stretching exercises as it was used in previous research [31]. Patients did not exceed their HR max. Telephone calls were made weekly to ensure patients were satisfied with the protocol and identify any problems with compliance. Patients were equipped with heart rate monitors (Beurer PM 25) to help them in sustaining the recommended heart rate. The main exercise was walking however subjects had an opportunity to use other modes of exercise, such as cycling and swimming on request.
Click to expand...

At the end, patients supposedly did 40 minutes of exercise of more than double the intensity (judging by heart rate), with additional stretching, for 5 times a week.
 
Last edited:
I would think it important to have more understanding and reporting of the dropouts. Else it's like doing a study on 69 cars to see if they pass an MOT test, and not knowing it some of the 50% dropped out because they couldn't make it to the test centre.
 
@strategist and @Trish Thanks.

I've rewatched it and it seems that they simply mention an anecdote of a patient doing GET and having worsened values on CPET.

The Belgian report had CPET info on patients who did GET and/or CBT with graded activity and the results were stable, rather than showing a decrease (there was no control group though).
 
Respiration key to increase oxygen in the brain
"Standard thought was that mammalian blood is always completely saturated with oxygen," said Patrick J. Drew, Huck Distinguished Associate Professor of Neural Engineering and Neurosurgery and associate director of the Penn State Neuroscience Institute.

That would mean that the only way to get more oxygen to the brain would be to get more blood to the brain by increasing blood flow. The researchers were interested in seeing how brain oxygen levels were affected by natural behaviors, specifically exercise.
Click to expand...
"We know that people change breathing patterns when doing cognitive tasks," said Drew. "In fact, respiration phase locks to the task at hand. In the brain, increases in neural activity usually are accompanied by increases in blood flow."

However, exactly what is happening in the body was unknown, so the researchers used mice who could chose to walk or run on a treadmill and monitored their respiration, neural activity, blood flow and brain oxygenation.

"We predicted that brain oxygenation would depend on neural activity and blood flow," said Qing Guang Zhang, postdoctoral fellow in engineering science and mechanics. "We expected the oxygenation would drop in the brain's frontal cortex if blood flow decreased.

"That was what we thought would happen, but then we realized it was the respiration that was keeping the oxygenation up."
Click to expand...
The only way that could happen would be if exercise was causing the blood to carry more oxygen, he explained, which would mean that the blood was not normally completely saturated with oxygen.
The researchers looked at oxygenation in the somatosensory cortex and the frontal cortex — which is an area involved in cognition — and the olfactory bulb — an area involved in the sense of smell — because they are the most accessible areas of the brain.
Click to expand...

https://news.psu.edu/story/600381/2019/12/04/research/respiration-key-increase-oxygen-brain

Would it not be possible to try increasing oxygen saturation without exercise?
From a bit of googling, oxygen saturation at night would also be something that could be looked at in pwME.

BUT not to test the 'deconditioning/fear of exercise' theory which should have been abandoned long ago.
 
Last edited:
Trish said:
So they started with 69 patients who met Fukuda criteria, but only 34 were able to do the CPET and the exercise program. That sounds to me as though the half who didn't complete were ME patients with PEM, and the other half probably didn't have PEM, so would not have met ME criteria such as IOM, ICC and CCC.
Click to expand...
This is a self-selection process that filters out ME patients and leaves idiopathic chronic fatigue patients. Sampling uncertainty is a fundamental problem in ME research and researchers are expected to know better.
Overall, it could be concluded that both acute physical exercise bout and effects of physical exercise programme can lead to cognitive function improvement in many patient populations
Click to expand...
This is not a valid conclusion without validating whether the tests have any meaningful significance, whereas they seem reductive and arbitrary.
 
On further reflection, I think the correct interpretation is that it is impossible to say what is really occurring, but the lack of a control group allows the possibility of all positive effects being merely regression to the mean. Prolonged postinfectious fatigue/symptoms is quite common but tends to resolve itself over time. It's possible that their cohort contains a relatively high percentage of these kind of patients.
 
Sly Saint said:
not looked into this polish researcher much before; study he did earlier in the year
concludes

uses Fukuda and most of usual scales for diagnosis (eg CFQ)
Prevalence and characteristics of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) in Poland: A cross-sectional study
https://www.researchgate.net/public...litis_CFSME_in_Poland_A_cross-sectional_study
Click to expand...

Thread here:
https://www.s4me.info/threads/preva...cross-sectional-study-2019-slomko-et-al.8484/
 
You must log in or register to reply here.
Back
Top Bottom