Trial Report Prominent Fatigue but No Motor Fatigability in Non-Hospitalized Patients With Post-COVID-Syndrome, 2023, Weich et al

[Kitty]

From @MSEsperanza:

Prominent Fatigue but No Motor Fatigability in Non-Hospitalized Patients With Post-COVID-Syndrome

Abstract

Objectives:
Fatigue is a frequent and often disabling symptom in patients with post-COVID syndrome. To better understand and evaluate the symptom of motor fatigue in the context of the post-COVID syndrome, we conducted treadmill walking tests to detect the phenomenon of motor fatigability or to evaluate whether evidence of organic lesions of the motor system could be found, similar to patients with multiple sclerosis.

Method:
Twenty-nine non-hospitalized patients with post-COVID syndrome completed the Fatigue Scale for Motor and Cognitive Function (FSMC) questionnaire to determine the trait component of subjective fatigue before they were tested on a treadmill walking at a moderate speed for up to 60 min or until exhaustion. During the walking test oxygen uptake, ventilation and acceleration data of both feet were collected. To determine motor performance fatigability, the Fatigue Index Kliniken Schmieder (FKS) was calculated using the attractor method.

Results:
The average walking duration was 42.7 ± 18.6 min with 15 subjects stopping the walking test prematurely. The FSMC score revealed a severe cognitive (37.6 ± 8.2) and motor (37.1 ± 7.8) fatigue averaged over all subjects but only two subjects showed an FKS above the normal range (>4), representing performance fatigability. There was no significant correlation between subjective fatigue (FSMC) and FKS as well as walking time. Absolute values of oxygen uptake and ventilation were in the normal range reported in literature (r = 0.9, p < 0.05), although eight subjects did not produce a steady-state behavior.

Conclusion:
Almost all patients with post-COVID syndrome and subjectively severe motor fatigue, did not show motor fatigability nor severe metabolic anomalies. This is argued against organic, permanent damage to the motor system, as is often seen in MS. Many of the patients were - to our and their own surprise - motorically more exertable than expected.

Keywords: attractor method; gait analysis; motor fatigability; motor fatigue; post-COVID-syndrome.


Citation:
Weich C, Dettmers C, Saile R, Schleicher L, Vieten M, Joebges M. Prominent Fatigue but No Motor Fatigability in Non-Hospitalized Patients With Post-COVID-Syndrome. Front Neurol. 2022 Jul 1;13:902502. doi: 10.3389/fneur.2022.902502. PMID: 35847205; PMCID: PMC9283824.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9283824/

 

[Kitty]

Also from @MSEsperanza:


This appears the study mentioned in the annual report of Kliniken Schmieder group (Germany) -- see this thread:

https://www.s4me.info/threads/germa...oup-2022-report-on-long-covid-research.35731/

Some quotes from the paper's discussion section that mentions ME/CFS:

"We were very much surprised that almost half of our patients were able to walk for 1 h on the treadmill at a fairly good speed around 5 km/h. Patients themselves were surprised that they managed to walk faster and longer than expected. Some of them complained about the backdrop the next day. Others did not experience the backdrop they had expected."

[So why didn't they repeat the testing at the following day in order to investigate whether there were objectively measurable differences between those groups?]

"The discrepancy between subjective complaints of the patients and missing objective deficits made some people claim that fatigue in post-COVID syndrome resembles or equals myeloencephalitis/chronic fatigue syndrome (ME/CFS).

"The subjective-objective cognitive mismatch in ME/CFS caused even a comparison to the functional cognitive disorder spectrum [(46) cited from (47)]. Fatigue, pain, and excessive interoceptive monitoring in ME/CFS may produce a shift from externally directed attention to subjective complaints, resulting in perceiving cognitive and motor tasks as extremely effortful (46)."

References include:

43. Pust GEA, Randerath J, Goetzmann L, Weierstall R, Korzinski M, Gold SM, et al.. Association of fatigue severity with maladaptive coping in multiple sclerosis: a data-driven psychodynamic perspective. Front Neurol.(2021) 12:652177. 10.3389/fneur.2021.652177 [PMC free article] [PubMed] [CrossRef] [Google Scholar]
44. Pust GEA, Dettmers C, Randerath J, Rahn AC, Heesen C, Schmidt R, et al.. Fatigue in multiple sclerosis is associated with childhood adversities. Front Psychiatry. (2020) 11:811. 10.3389/fpsyt.2020.00811 [PMC free article] [PubMed] [CrossRef] [Google Scholar]

46. Teodoro T, Edwards MJ, Isaacs JD. A unifying theory for cognitive abnormalities in functional neurological disorders, fibromyalgia and chronic fatigue syndrome: systematic review. J Neurol Neurosurg Psychiatry.(2018) 89:1308–19. 10.1136/jnnp-2017-317823 [PMC free article] [PubMed] [CrossRef] [Google Scholar]


More from the discussion section:

"Since there does not exist any motor, and only a few metabolic, potentially unspecific, anomalies emerging in our patient sample, we expect that psychosocial factors may be contributing or driving forces in the course of the disease for the patients."

"However, this can only be confirmed on the basis of future studies. The test design will be extended in order to allow a deeper investigation of the metabolic processes: Here, lactate measurements will be used as a marker for anaerobic energy utilization as well as heart rate data to gain insights into the acute response of the cardiovascular system.

"Furthermore, cooperative groups from the Schmieder Clinics as well as the University of Konstanz will conduct investigations on cognitive, emotional, and endocrine function or combined effects. Structured clinical interviews and neuroimaging (fMRI) will be used in our group to assess psychosomatic and psychiatric comorbidities."

So they plan to do more studies -- even if their wording appears to indicate that the purpose is to confirm their belief in 'psychosocial factors', maybe still a chance that they will properly investigate PEM?

@PhysiosforME
@dave30th

Conclusion:
Initially, non-hospitalized patients with post-COVID syndrome should be examined with a holistic and multidisciplinary approach. After exclusion of cardiac and pulmonary deficits, patients in our sample with prominent fatigue did not show any signs of motor performance fatigability like patients with MS. This implies that we did not find signs of a lesion of the central motor system despite the prominent complaint of motor fatigue.

It was not clear whether mild anomalies in ventilation were caused by metabolic or psychogenic alterations. Additional investigation of lactate and heart rate data will be helpful. Nevertheless, the test procedure used here has proven to be very useful for detecting motor and metabolic changes during physical exertion in patients complaining about fatigue. We assume that psychiatric and psychosomatic comorbidities may be involved in many initially non-hospitalized patients with post-COVID-syndrome.

 

[bobbler]

Would/does the term 'fatiguability' apply to the findings from the 2nd day on a Workwell 2-day CPET?

Or indeed from other more recent research such as the @PhysiosforME home-based studies?