Category: Methodology

System and methods to determine ME/CFS & Long Covid disease severity using wearable sensor & survey data

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating disease with high probability of misdiagnosis and significant unmet medical needs that affects as many as 2.5 million people in the U.S. and causes enormous burden for patients, their caregivers, the healthcare system and society. Between 84 to 91 percent of ME/CFS patients are not yet diagnosed [6, 19], and at least one-quarter of ME/CFS patients are house- or bedbound at some point in their lives [12, 13]. The impact of ME/CFS to the U.S. economy, is about $17 to $24 billion in medical bills and lost income from lost household and labor force productivity per year [7, 13].

Current widely used diagnosis methods of ME/CFS and other diseases with similar clinical symptoms like Long COVID [6, 21] are highly dependent on patients’ self reporting [4, 5] and standardized survey, which are not optimal for medical diagnosis. In a joint study with The Bateman Horne Center (BHC)1, we designed and developed a system prototype that was able to stably collect terabytes of inertial measurement unit (IMU) time-series data, and analyzed multiple candidate parameters derived from them that could be used as reliable biomarkers for ME/CFS and other diseases with similar clinical symptoms.

Utilizing our system prototype, MetaProcessor, we conducted grouped t-tests on data collected from the EndoPAT study group (55 recruited, 51 participated, 30 ME/CFS, 15 Long COVID, 6 healthy control) to evaluate the predictive power of Upright Position Time (UpTime), Hours of Upright Activity (HUA), and Steps/Day. Through statistical analysis, we were able to assert the following for ME/CFS versus healthy control:

1. UpTime yielded a low p-value of 0.00004, indicating a significant difference between the groups and demonstrating its potential as a reliable measure for differentiating ME/CFS from healthy control populations.

2. HUA had a p-value of less than 0.00004, suggesting it could also serve as a useful measure for distinguishing ME/CFS from healthy control groups.

3. Steps/Day, x-axis and y-axis, had p-values of 0.01059 and 0.08665, respectively, indicating that step count may be relevant for differentiating ME/CFS individuals from healthy controls, but step count alone may not be sufficient to reliably distinguish between these groups.

In a linear regression analysis, we found a moderately positive correlation between UpTime and HUA with r 2 = 0.68. Overall, we can confidently conclude that UpTime is a superior overall predictor due to its objective nature and the lowest p-values observed across all groups.

Source: System and methods to determine ME/CFS & Long Covid disease severity using wearable sensor & survey data. Sun, Y. Thesis, Bachelor of Science, The University of Utah. https://ccs.neu.edu/~ysun/publications/system-and-methods-to-determine-mecfs-and-longcovid-disease-severity-using-wearable-sensor-and-survey-data.pdf (Full text)

Comparing Frequency and Severity Ratings for ME/CFS versus Controls

Abstract:

Most questionnaires for somatic symptoms focus on occurrence, frequency, or severity, and in doing so, they might not be able to comprehensively assess the burden that symptoms present to patients. For example, a symptom might occur at a high frequency but only a minimal severity, so that it is less likely to be a burden on a patient; whereas a symptom that has both a high frequency and severity is more likely to be negatively impacting a patient.
Study 1 examined frequency and severity scores for classic Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) symptoms among patients with ME/CFS versus a control group. Findings in Study 1 indicate there were more frequency/severity discrepancies for individuals with ME/CFS versus the control group. Study 1 concluded that collecting data on both measures of symptom burden provides unique indicators that can better assess the burden of the symptoms on patients.
In a separate data set, Study 2 reported reliability data on slight differences in the time period and the way the severity was assessed. Study 2 findings indicated high levels of reliability for these changes in the time period and the way questions were asked. These studies provide important psychometric properties that could lead to more reliable and valid assessments of patients with post-viral illnesses.
Source: Jason LA, Benner S, Hansel N. Comparing Frequency and Severity Ratings for ME/CFS versus Controls. Psych. 2023; 5(3):662-669. https://doi.org/10.3390/psych5030042 https://www.mdpi.com/2624-8611/5/3/42 (Full text)

Comparison of a 20 degree and 70 degree tilt test in adolescent myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) patients

Abstract:

Introduction: During a standard 70-degree head-up tilt test, 90% of adults with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) develop an abnormal reduction in cerebral blood flow (CBF). A 70-degree test might not be tolerated by young ME/CFS patients because of the high incidence of syncopal spells. This study examined whether a test at 20 degrees would be sufficient to provoke important reductions in CBF in young ME/CFS patients.

Methods: We analyzed 83 studies of adolescent ME/CFS patients. We assessed CBF using extracranial Doppler measurements of the internal carotid and vertebral arteries supine and during the tilt. We studied 42 adolescents during a 20 degree and 41 during a 70 degree test.

Results: At 20 degrees, no patients developed postural orthostatic tachycardia (POTS), compared to 32% at 70 degrees (p = 0.0002). The CBF reduction during the 20 degree tilt of -27(6)% was slightly less than during the reduction during a 70 degree test [-31(7)%; p = 0.003]. Seventeen adolescents had CBF measurements at both 20 and 70 degrees. The CBF reduction in these patients with both a 20 and 70 degrees test was significantly larger at 70 degrees than at 20 degrees (p < 0.0001).

Conclusions: A 20 degree tilt in young ME/CFS patients resulted in a CBF reduction comparable to that in adult patients during a 70 degree test. The lower tilt angle provoked less POTS, emphasizing the importance of using the 70 degree angle for that diagnosis. Further study is needed to explore whether CBF measurements during tilt provide an improved standard for classifying orthostatic intolerance.

Source: van Campen CLMC, Rowe PC, Visser FC. Comparison of a 20 degree and 70 degree tilt test in adolescent myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) patients. Front Pediatr. 2023 May 12;11:1169447. doi: 10.3389/fped.2023.1169447. PMID: 37252045; PMCID: PMC10213432. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10213432/ (Full text)

Free-water-corrected diffusion and adrenergic/muscarinic antibodies in myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Background and purpose: Free-water-corrected diffusion tensor imaging (FW-DTI), a new analysis method for diffusion MRI, can indicate neuroinflammation and degeneration. There is increasing evidence of autoimmune etiology in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). We used FW-DTI and conventional DTI to investigate microstructural brain changes related to autoantibody titers in patients with ME/CFS.

Methods: We prospectively examined 58 consecutive right-handed ME/CFS patients who underwent both brain MRI including FW-DTI and a blood analysis of autoantibody titers against β1 adrenergic receptor (β1 AdR-Ab), β2 AdR-Ab, M3 acetylcholine receptor (M3 AchR-Ab), and M4 AchR-Ab. We investigated the correlations between these four autoantibody titers and three FW-DTI indices-free water (FW), FW-corrected fractional anisotropy (FAt), and FW-corrected mean diffusivity-as well as two conventional DTI indices-fractional anisotropy (FA) and mean diffusivity. The patients’ age and gender were considered as nuisance covariates. We also evaluated the correlations between the FW-DTI indices and the performance status and disease duration.

Results: Significant negative correlations between the serum levels of several autoantibody titers and DTI indices were identified, mainly in the right frontal operculum. The disease duration showed significant negative correlations with both FAt and FA in the right frontal operculum. The changes in the FW-corrected DTI indices were observed over a wider extent compared to the conventional DTI indices.

Conclusions: These results demonstrate the value of using DTI to assess the microstructure of ME/CFS. The abnormalities of right frontal operculum may be a diagnostic marker for ME/CFS.

Source: Kimura Y, Sato W, Maikusa N, Ota M, Shigemoto Y, Chiba E, Arizono E, Maki H, Shin I, Amano K, Matsuda H, Yamamura T, Sato N. Free-water-corrected diffusion and adrenergic/muscarinic antibodies in myalgic encephalomyelitis/chronic fatigue syndrome. J Neuroimaging. 2023 May 27. doi: 10.1111/jon.13128. Epub ahead of print. PMID: 37243973. https://pubmed.ncbi.nlm.nih.gov/37243973/

Natural killer cytotoxicity in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a multi-site clinical assessment of ME/CFS (MCAM) sub-study

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a multisystem illness characterized by substantial reduction in function accompanied by profound unexplained fatigue not significantly relieved by rest, post-exertional malaise, and other symptoms. Reduced natural killer (NK) cell count and cytotoxicity has been investigated as a biomarker for ME/CFS, but few clinical laboratories offer the test and multi-site verification studies have not been conducted.

Methods: We determined NK cell counts and cytotoxicity in 174 (65%) ME/CFS, 86 (32%) healthy control (HC) and 10 (3.7%) participants with other fatigue associated conditions (ill control [IC]) from the Multi-Site Clinical Assessment of ME/CFS (MCAM) study using an assay validated for samples shipped overnight instead of testing on day of venipuncture.

Results: We found a large variation in percent cytotoxicity [mean and (IQR) for ME/CFS and HC respectively, 34.1% (IQR 22.4-44.3%) and 33.6% (IQR 22.9-43.7%)] and no statistically significant differences between patients with ME/CFS and HC (p-value = 0.79). Analysis stratified on illness domain measured with standardized questionnaires did not identify an association of NK cytotoxicity with domain scores. Among all participants, NK cytotoxicity was not associated with survey results of physical and mental well-being, or health factors such as history of infection, obesity, smoking, and co-morbid conditions.

Conclusion: These results indicate this assay is not ready for clinical implementation and studies are needed to further explore immune parameters that may be involved in the pathophysiology of ME/CFS.

Source: Querec TD, Lin JS, Chen Y, Helton B, Kogelnik AM, Klimas NG, Peterson DL, Bateman L, Lapp C, Podell RN, Natelson BH, Unger ER; MCAM Study Group. Natural killer cytotoxicity in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a multi-site clinical assessment of ME/CFS (MCAM) sub-study. J Transl Med. 2023 Apr 3;21(1):242. doi: 10.1186/s12967-023-03958-2. PMID: 37013608. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03958-2 (Full text)

Development and measurement properties of the PEM/PESE activity questionnaire (PAQ)

Abstract:

Background: Existing instruments often are inappropriate to measure the effects of post-exertional malaise (PEM) and post-exertional symptom exacerbation (PESE) on activities of daily living (ADLs). A validated questionnaire to measure self-reported ability with ADLs would advance research and clinical practice in conditions like myalgic encephalomyelitis and Long Covid.

Objective: Determine the measurement properties of the PEM/PESE Activity Questionnaire (PAQ).

Methods: The PAQ is adapted from the Patient Specific Functional Scale. Respondents rated three self-selected ADLs on two 0-100 scales, including current performance compared to (1) a ‘good day’ and (2) before illness. Respondents provided a Burden of Functioning rating on a 0-100 scale, anchored at 0 being the activity took “No time, effort, and resources at all” and 10 being “All of my time, effort, and resources.” Respondents took the PAQ twice, completing a demographic questionnaire after the first PAQ and before the second PAQ. Descriptive statistics and intraclass correlation coefficients were calculated for each scale to assess test-retest reliability. Minimum detectable change outside the 95% confidence interval (MDC95) was calculated. Ceiling and floor effects were determined when the MDC95 for average and function scores crossed 0 and 100, respectively.

Results: n = 981 responses were recorded, including n = 675 complete surveys. Test-retest reliability was generally fair to excellent, depending on function and scale. MDC95 values generally indicated scale responsiveness. Ceiling and floor effects were noted infrequently for specific functions.

Conclusion: The PAQ is valid, reliable, and sensitive. Additional research may explore measurement properties involving functions that were infrequently selected in this sample.

Source: Davenport TE, Stevens SR, Stevens J, Snell CR, Van Ness JM. Development and measurement properties of the PEM/PESE activity questionnaire (PAQ). Work. 2023 Mar 13. doi: 10.3233/WOR-220553. Epub ahead of print. PMID: 36938768. https://content.iospress.com/articles/work/wor220553 (Full text)

Developing a blood cell-based diagnostic test for myalgic encephalomyelitis/chronic fatigue syndrome using peripheral blood mononuclear cells

Abstract:

A blood-based diagnostic test for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and multiple sclerosis (MS) would be of great value in both conditions, facilitating more accurate and earlier diagnosis, helping with current treatment delivery, and supporting the development of new therapeutics.

Here we use Raman micro-spectroscopy to examine differences between the spectral profiles of blood cells of ME/CFS, MS and healthy controls.

We were able to discriminate the three groups using ensemble classification models with high levels of accuracy (91%) with the additional ability to distinguish mild, moderate, and severe ME/CFS patients from each other (84%).

To our knowledge, this is the first research using Raman micro-spectroscopy to discriminate specific subgroups of ME/CFS patients on the basis of their symptom severity. Specific Raman peaks linked with the different disease types with the potential in further investigations to provide insights into biological changes associated with the different conditions.

Source: Jiabao Xu, Tiffany Lodge,  Caroline Claire Kingdon, James W L Strong, John Maclennan, Eliana Lacerda, Slawomir Kujawski, Pawel Zalewski, Wei Huang, Karl J. Morten. Developing a blood cell-based diagnostic test for myalgic encephalomyelitis/chronic fatigue syndrome using peripheral blood mononuclear cells. medRxiv [Preprint] medRxiv 2023.03.18.23286575; doi: https://doi.org/10.1101/2023.03.18.23286575 https://www.medrxiv.org/content/10.1101/2023.03.18.23286575v1.full-text (Full text)

The Conners Continuous Performance Test CPT3™: Is it a reliable marker to predict neurocognitive dysfunction in Myalgic encephalomyelitis/chronic fatigue syndrome?

Introduction: The main objective is to delimit the cognitive dysfunction associated with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) in adult patients by applying the Continuous Performance Test (CPT3™). Additionally, provide empirical evidence on the usefulness of this computerized neuropsychological test to assess ME/CFS.

Method: The final sample (n = 225; 158 Patients/67 Healthy controls) were recruited in a Central Sensitization Syndromes (CSS) specialized unit in a tertiary hospital. All participants were administered this neuropsychological test.

Results: There were significant differences between ME/CFS and healthy controls in all the main measures of CPT3™. Mainly, patients had a worse indicator of inattentiveness, sustained attention, vigilance, impulsivity, slow reaction time, and more atypical T-scores, which is associated with a likelihood of having a disorder characterized by attention deficits, such as Attention Deficit Hyperactivity Disorder (ADHD). In addition, relevant correlations were obtained between the CPT3™ variables in the patient’s group. The most discriminative indicators of ME/CFS patients were Variability and Hit Reaction Time, both measures of response speed.

Conclusion: The CPT3™ is a helpful tool to discriminate neurocognitive impairments from attention and response speed in ME/CFS patients, and it could be used as a marker of ME/CFS severity for diagnosing or monitoring this disease.

Source: Fernández-Quirós J, Lacasa-Cazcarra M, Alegre-Martín J, Sanmartín-Sentañes R, Almirall M, Launois-Obregón P, Castro-Marrero J, Rodríguez-Urrutia A, Navarro-Sanchis JA and Ramos-Quiroga JA (2023) The Conners Continuous Performance Test CPT3™: Is it a reliable marker to predict neurocognitive dysfunction in Myalgic encephalomyelitis/chronic fatigue syndrome? Front. Psychol. 14:1127193. doi: 10.3389/fpsyg.2023.1127193 https://www.frontiersin.org/articles/10.3389/fpsyg.2023.1127193/full (Full text)

Using Data Mining and Time Series to Investigate ME and CFS Naming Preferences

Abstract:

There have been numerous iterations of naming convention specified for Myalgic Encephalomyelitis (ME) and Chronic Fatigue Syndrome (CFS). As health care turns to “big data” analytics to gain insights, the Google Trends database was mined to ascertain worldwide trends of public interest in several ME- and CFS-related search categories between 2004 and 2019.
Time series analysis revealed that though “Chronic Fatigue Syndrome” remains the predominant search category in the ME and CFS field, the interest index declined at a rate of 2.77 per month during the 15-year study period. In the same time period, the interest index in “ME/CFS Hybrid” terms increased at a rate of 3.20 per month. Potential causal mechanisms for these trends and implications for patient sentiment analysis are discussed.
Source: Bhatia, S., & Jason, L. A. (2023). Using Data Mining and Time Series to Investigate ME and CFS Naming Preferences. Journal of Disability Policy Studies, 0(0). https://doi.org/10.1177/10442073231154027

Evaluating the ability of patient reported outcome measures to represent the functional limitation of people living with myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Aim: To identify activities which people with Myalgic Encephalomyelitis (ME)/Chronic Fatigue Syndrome (CFS) report are impacted by their condition, and evaluate the ability of measures of function used by National Health Service (NHS) ME/CFS Services to represent these experiences.

Method: 122 participants completed ME/CFS Service questionnaires reporting activities that they had reduced or stopped doing, as well as Patient Reported Outcome Measures (PROMs). These data were coded using the International Classification of Functioning, Disability and Health (ICF) using established linking rules. Matrices identified the agreement rate between the outcome measures and the participant-generated list. Activities which could not be coded against the ICF were grouped using content analysis.

Results: Responses from participants related to codes from nine subsections of the ICF. The PROMs used by the ME/CFS service had agreement rates between 58% and 62.5% with the participant-generated list. The content analysis identified a range of activities that were meaningful to participants that they could no longer do. These included holidays and day trips, accessing the community independently, and sustaining activity into the evening. These were not captured in either the ICF or the service’s outcome measures.

Conclusion: The list generated by participants referred to a wide range of activities, including some not captured by the ICF. Comparison against the outcome measures suggests that the measures used in many NHS ME/CFS services nationally capture patients’ experiences moderately well. However, there are activities that patients value that are not captured by these measures.

Source: Bethan Jones, Corin Bourne & Peter Gladwell. Evaluating the ability of patient reported outcome measures to represent the functional limitation of people living with myalgic encephalomyelitis/chronic fatigue syndrome. Fatigue: Biomedicine, Health & Behavior, DOI: 10.1080/21641846.2023.2175579 (Full text)