Category: Pediatric ME/CFS

Characterizing Pediatric Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Symptom Burden, Functional Impairment, and Comparison With Adults in the Multi-Site Clinical Assessment of ME/CFS (MCAM) Study

Abstract:

Objectives: To characterize the clinical, functional, and educational characteristics of adolescents with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and compare selected illness domains with adults in the Multi-Site Clinical Assessment of ME/CFS (MCAM) study.

Study design: Baseline cross-sectional data from adolescents aged 10-17 years enrolled in MCAM were analyzed. Standardized measures included the Short Form-36 (SF-36v2), CDC Symptom Inventory (CDC-SI), Multidimensional Fatigue Inventory (MFI-20), and selected domains of the DePaul Questionnaire. Descriptive statistics characterized the pediatric cohort and bivariate analyses compared adolescents with adults enrolled in MCAM.

Results: Forty adolescents (mean age 15.3 years; 52.5% female) were included. Mean illness duration was 4.0 years. Educational disruption was substantial: 64% received homebound or homeschool instruction, 89% missed school because of illness, and participants missed a mean of 10.8 school days during the preceding month. Physical health-related quality of life was substantially impaired. Persistent post-exertional malaise (PEM), unrefreshing sleep, fatigue, and neurocognitive symptoms were common. Compared with adults (n = 595), adolescents had shorter illness duration and better physical functioning, vitality, and social functioning, whereas mental health scores were similar. Adults reported greater burden across several physical symptom domains although many between-group differences were small.

Conclusions: Adolescents with ME/CFS experience substantial multisystem symptom burden, impaired physical functioning and educational disruption. Many core clinical features were similar to those in adults, supporting the need for early recognition and appropriate clinical and educational support.

Source: Weaver SS, Regan JJ, Issa A, Fall EA, Chen Y, Lin JS, Unger ER. Characterizing Pediatric Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Symptom Burden, Functional Impairment, and Comparison With Adults in the Multi-Site Clinical Assessment of ME/CFS (MCAM) Study. J Pediatr. 2026 Oct 6:115361. doi: 10.1016/j.jpeds.2026.115361. Epub ahead of print. PMID: 42838410. https://www.jpeds.com/article/S0022-3476(26)00389-6/fulltext (Full text)

Clinical Symptomatology, Cognition and Psychosocial Wellbeing in Adolescents With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Cross-Sectional Observational Study

Abstract:

Aim: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a disabling illness that frequently begins in adolescence, yet adolescents with ME/CFS remain an under-researched population. We aimed to characterise the cognitive and psychosocial wellbeing of adolescents with ME/CFS relative to normative benchmarks and unaffected age-peers.

Methods: Adolescents with mild-to-moderate ME/CFS (n = 25) and healthy controls (n = 25) aged 10-19 years were recruited in Melbourne, Australia. Each completed a set of clinical questionnaires and cognitive assessments to assess ME/CFS symptomatology, school functioning, psychosocial wellbeing and cognition. Their caregivers also completed questionnaires regarding their psychosocial wellbeing and everyday executive functioning.

Results: Adolescents with ME/CFS showed significantly reduced information processing speed, though other measures of intellectual functioning did not differ consistently between groups. The ME/CFS group also reported significantly poorer sleep, quality of life and higher levels of anxiety and depression. Caregivers further identified significant attention and working memory concerns in the ME/CFS group, but reported no differences in internalising behaviours between groups.

Conclusion: Adolescents with ME/CFS experience substantial psychosocial and physical burden because of their illness. Cognitive difficulties in ME/CFS may reflect inefficiencies in information processing speed and fluctuating symptom burden. Discrepancies between adolescent self-report and caregiver ratings underscore the importance of inclusive perspectives in ME/CFS management. These findings support the need for flexible, paced educational and clinical accommodations and for further research into the dynamic cognitive profile of adolescents with ME/CFS across a more representative population.

Source: Chau T, Josev EK, Scheinberg A, Thomas N, McDonald F, Reveley C, Gooley PR, Armstrong C, Knight S. Clinical Symptomatology, Cognition and Psychosocial Wellbeing in Adolescents With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Cross-Sectional Observational Study. J Paediatr Child Health. 2026 Sep 20. doi: 10.1111/jpc.70587. Epub ahead of print. PMID: 42764669. https://onlinelibrary.wiley.com/doi/10.1111/jpc.70587 (Full text)

Postural orthostatic tachycardia syndrome in adolescents with ME/CFS – a case control study

Abstract:

Introduction: Postural orthostatic tachycardia syndrome (PoTS) can be associated with myalgic encephalomyelitis/ chronic fatigue syndrome (ME/CFS). Pediatric PoTS requires a “sustained” rise in orthostatic heart rate ≥40 bpm above supine heart rate (relative limit), often >120 bpm (absolute limit). However, the diagnostic criteria for PoTS in adolescents remain underexplored, particularly regarding the definition of “sustained” tachycardia, which poses challenges in clinical and research settings. This study examined orthostatic intolerance criteria, including PoTS, in adolescents with ME/CFS and healthy controls.

Methods: Medical history of orthostatic intolerance was assessed by a semi-structured interview with 18 ME/CFS patients and 18 matched healthy controls (14-17 years). A passive 10-min standing test with minute-by-minute heart rate and blood pressure registration was performed. PoTS was diagnosed by a clinical expert based on current consensus criteria. Data were analyzed using Fisher’s exact test and receiver operating characteristic analysis.

Results: Although history of orthostatic intolerance was positive in 15/18 ME/CFS [83%, 0.95 CI (61; 94)] and 3/18 healthy controls [17%, 0.95 CI (5.9; 39)], PoTS was diagnosed in only 7/18 ME/CFS [39%, 0.95 CI (20; 61)] vs. no healthy controls [0%, 0.95 CI (0; 18)]. Subgroups were identified, e.g., positive history of orthostatic intolerance yet physiological passive 10-min standing test, or negative history of orthostatic intolerance yet tachycardia in passive 10-minute standing test. PoTS diagnosis by the clinical expert matched best with the passive 10-min standing test alone when at least 60% of upright heart rate values were above one or both limits. The absolute limit was superior to the relative limit in distinguishing adolescents with and without PoTS.

Discussion: PoTS was observed only in ME/CFS. In adolescents with ME/CFS, positive history of orthostatic intolerance, along with at least 60% of heart rate values above published upright-position limits, may allow non-experts to make a valid diagnosis, facilitating clinical care and future studies. Further research will show if these results can be generalized.

Source: Leone A, Gerrer K, Viereck A, Grabbe A, Kircher A, Behrends U, Maier A. Postural orthostatic tachycardia syndrome in adolescents with ME/CFS – a case control study. Front Pediatr. 2026 Sep 1;14:1836407. doi: 10.3389/fped.2026.1836407. PMID: 42746015; PMCID: PMC13574936. https://pmc.ncbi.nlm.nih.gov/articles/PMC13574936/ (Full text)

Handgrip strength in children, adolescents, and young adults with suspected myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) in children, young people (CYP) lacks validated diagnostic biomarkers. Post-exertional malaise (PEM) is central to case definitions and is usually assessed by patient report. We evaluated the feasibility and clinical value of handgrip strength (HGS) testing in PEM-reporting CYP referred for suspected ME/CFS.

Methods: In this prospective observational study at the Munich Chronic Fatigue Center for Young People (November 2022-November 2024), 147 patients (10-25 years) referred for the assessment of ME/CFS with positive DSQ-PEM screening and 83 healthy controls (HC) completed two HGS sessions (10 maximal grips/session; 3-s contraction/5-s rest; 60-minute inter-session break) using a digital dynamometer. We derived maximal force (Fmax), mean force (Fmean), fatigue ratio (FR = Fmax/Fmean), and recovery ratio (RR = Fmean session 2 / session 1). Analyses used repeated-measures ANCOVA, linear regression, partial Spearman correlations (adjusted for sex, age, and BMI), and proportional odds models for group membership (HC, noME/CFS, ME/CFS), reporting accuracy, and the C-statistic. Sensitivity analyses compared noME/CFS with confirmed CCC-ME/CFS.

Results: After clinical work-up, 84/147 (57%) patients were classified as ME/CFS (confirmed or probable) and 63/147 (43%) as noME/CFS. HGS test completion rate was high (session 1: 146/147, 99.3%; session 2: 142/147, 96.6%). Compared with HC, patients had substantially lower HGS (mean difference -9.93 kg, 95% CI: -12.00 to -7.85), and HGS indices correlated modestly with physical functioning (SF-12 PCS), but not with PEM duration. Both noME/CFS and ME/CFS groups differed from HC in absolute strength indices (Fmean, Fmax) and FR. RR differed between ME/CFS and HC, whereas no HGS index significantly separated noME/CFS from ME/CFS. In proportional odds models, each HGS index improved fit (all p < 0.001), but discrimination across HC, noME/CFS, and ME/CFS patients was moderate (accuracy 49.2-57.3% vs no-information rate 36.5%, with best performance for Fmean in session 2). In the CCC-restricted sensitivity analysis, discrimination between confirmed CCC-ME/CFS and noME/CFS was moderate (accuracy 62.8-70.7%; C-statistic 0.63-0.73), with best performance for absolute strength indices and RR.

Conclusions: Standardized two-session repeated HGS testing is feasible in CYP with chronic fatigue and self-reported PEM and provides an objective marker of functional impairment that aligns with physical health status but not with PEM duration. However, HGS alone shows limited ability to discriminate ME/CFS from other fatiguing noME/CFS conditions. HGS may be useful for quantitative phenotyping, patient stratification, and longitudinal outcome assessment rather than as a standalone diagnostic biomarker.

Source: Mihatsch L, Schartner L, de Luna JL, Höhler C, Bucka L, Lovrenovic L, Eidenschink S, Schmuck B, Bienemann V, Christa C, Mittelstraß K, Hausruckinger A, Warlitz C, Michel K, Gerrer K, Freitag H, Scheibenbogen C, Pricoco R, Behrends U. Handgrip strength in children, adolescents, and young adults with suspected myalgic encephalomyelitis/chronic fatigue syndrome. J Transl Med. 2026 Jul 15. doi: 10.1186/s12967-026-08654-5. Epub ahead of print. PMID: 42458481. https://link.springer.com/article/10.1186/s12967-026-08654-5 (Full text available as PDF file)

Novel activity and participation scales for children, adolescents, and young adults with postacute infection and vaccination syndromes and/or ME/CFS

Abstract:

Children, adolescents, and young adults (CYP) with postacute infection and vaccination syndromes (PAIVS), and/or myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), experience profound loss in activity and participation. We introduce and psychometrically validate two new brief, age-adapted, and domain-specific questionnaires for clinical use assessing activity and participation in this vulnerable patient group.

For this, 91 patients (aged 10-25 years) were assessed at the Munich Chronic Fatigue Center (MCFC) from 12/2022 to 11/2024. We designed the MCFC Activity Scale and MCFC Participation Scale and assessed construct validity using confirmatory factor analysis for both questionnaires. Reliability was evaluated via Cronbach’s α. Factor-based MCFC Activity and Participation Scores (0-100) were derived and correlated with Bell Score, FSS, DSQ-PEM, and SF-12 Component Summary Scales (PCS and MCS). Discrimination for ME/CFS was evaluated using ROC analyses. Participants (mean age 15.6 ± 2.4 years) were predominantly female (64%). 65% were diagnosed with ME/CFS.

The MCFC Activity Scale showed excellent one-factor fit (comparative fit index, CFI = 1.00) and good internal consistency (α = 0.82). The MCFC Participation Scale showed good internal consistency (α = 0.85) and acceptable one-factor fit (CFI = 0.817). Factor-based activity and participation were strongly correlated yet distinct (r = 0.73). Derived MCFC Activity and Participation Scores differed significantly by ME/CFS diagnosis (p ≤ 0.009). Scores correlated with Bell Score, FSS, DSQ-PEM, and SF-12 PCS (all p ≤ .002). For ME/CFS discrimination, the Activity Score achieved an AUC = 0.78 and the Participation Score an AUC = 0.72.

Conclusion: The Activity Scale demonstrated strong construct validity. The Participation Scale showed good internal consistency. Both scores demonstrated good convergent validity with established patient-reported outcome measures, supporting clinical utility. They may serve as pragmatic screening tools for this vulnerable patient group.

Source: Weidmann C, Grabbe A, Eberhartinger M, Kircher A, Leone A, Warlitz C, Stojanov S, Behrends U, Mihatsch LL. Novel activity and participation scales for children, adolescents, and young adults with postacute infection and vaccination syndromes and/or ME/CFS. Eur J Pediatr. 2026 Jun 5;185(7):471. doi: 10.1007/s00431-026-07125-9. PMID: 42249231. https://link.springer.com/article/10.1007/s00431-026-07125-9 (Full text)

Validation of the Wood Mental Fatigue Inventory in adolescents with myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Background: There is no consensus regarding the most reliable and valid measures of cognitive dysfunction in adolescents and adults with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). The Wood Mental Fatigue Inventory (WMFI) is commonly used in adults while the Pediatric Quality of Life Multidimensional Fatigue Scale (PedsQL MFS) is commonly used in adolescents. This study examined whether the WMFI was valid in adolescents.

Methods: Over a two-year period, participants in a cohort study completed four questionnaires: PedsQL, PedsQL MFS, Functional Disability Inventory (FDI), and WMFI. We examined the validity of the WMFI in 55 healthy adolescents and 55 with ME/CFS, determined how well the WMFI and PedsQL MFS cognitive fatigue subscale correlated with one another and with general quality of life surveys, and examined each questionnaire’s responsiveness to change over time.

Results: The PedsQL MFS cognitive fatigue subscale and the WMFI had a strong negative correlation for both healthy controls and ME/CFS patients at baseline with R2 values of 0.3915 and 0.8049 respectively. There was a similar strong negative correlation (R2 = 0.7739) between the two questionnaires in ME/CFS participants at the 24 month point of follow-up after multi-modal treatment. Each questionnaire was found to be similarly responsive to change.

Conclusion: The WMFI had a high correlation with the PedsQL MFS cognitive fatigue subscale. The WMFI has the advantage of ease of scoring. Both measures were responsive to changes in mental fatigue among those with ME/CFS over time.

Source: Welch DC, Edwards CC, Broussard CA, Swope ME, Christoforou ME, Matson PA, Azola AM, Rowe PC. Validation of the Wood Mental Fatigue Inventory in adolescents with myalgic encephalomyelitis/chronic fatigue syndrome. Brain Behav Immun Health. 2026 Mar 25;53:101222. doi: 10.1016/j.bbih.2026.101222. PMID: 41953581; PMCID: PMC13053862. https://pmc.ncbi.nlm.nih.gov/articles/PMC13053862/ (Full text)

ICD-10 Diagnoses prior to ME/CFS diagnosis in children and young people suggest potential early diagnostic indicators

Abstract:

To identify ICD-10-GM codes recorded in the year preceding a Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) diagnosis, we conducted a 1:5 matched case–control study using statutory health insurance data of 6–27-year-olds with ME/CFS (ICD-10-GM: G93.3, 2020–2022). Cases (n = 6,077) were matched 1:5 to controls by birth year, sex, and postal code. ICD-10-GM codes from the preceding year were analyzed using multivariable conditional logistic regression, reporting odds ratios (OR) and 95% confidence intervals. Most cases were female and aged 18–27 years.

Forty-four ICD-10-GM code classes were associated with increased and four with decreased odds, spanning 13 diagnostic chapters. Most associations were in chapters F (mental/behavioral disorders), R (respiratory diseases), and M (musculoskeletal disorders). Frequent conditions included fatigue, depression, pain disorders, and somatoform disorders (≥ 10% in cases; ORs 1.11–2.19. Rare diagnoses (≤ 1% prevalence), such as fibromyalgia (OR 2.08, 95% CI: 1.20–3.59) and mild cognitive impairment (2.93, 1.21–7.10), were strongly associated. Four COVID-19 or vaccination-related code classes were identified, with post-COVID-19 condition showing the highest OR (3.84, 2.97–4.98). Several ICD-10-GM codes, including COVID-19 related codes, were associated with later ME/CFS diagnoses.

Prospective studies should clarify timing relative to ME/CFS onset, and distinguish between pre-existing conditions, comorbidities, early manifestations, or misdiagnoses.

Source:Wirth M, Haastert B, Linnenkamp U, Andrich S, Icks A, Pricoco R, Behrends U, De Bock F. ICD-10 Diagnoses prior to ME/CFS diagnosis in children and young people suggest potential early diagnostic indicators. Sci Rep. 2026 Feb 26. doi: 10.1038/s41598-026-40848-1. Epub ahead of print. PMID: 41741569. https://www.nature.com/articles/s41598-026-40848-1 (Full text)

Proposed Mechanistic Axis of Infections and mTOR Hyperactivation: A Multidisciplinary Review of Immune, Rheumatologic, and Psychiatric Links

Abstract:

Early-life infections can produce durable changes in immune function and behavior. We propose a mechanistic hypothesis positioning the mechanistic target of rapamycin (mTOR) as the link between peripheral inflammation and central nervous system dysfunction in pediatric post-infectious syndromes. Based on clinical, translational, and experimental literature, we outline a stepwise pathway.

First, sustained mTOR activation skews T-cell and macrophage differentiation toward pro-inflammatory and autoimmune states. Second, endothelial mTOR signaling weakens tight junctions and increases vesicular transport, compromising blood-brain barrier integrity. Third, cytokines and sometimes autoreactive cells enter the brain and engage mTOR in microglia and neurons, driving neuroinflammation, impaired synaptic maintenance and plasticity, and neurotransmitter disruption.

This framework accounts for features observed in Long COVID, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and pediatric acute neuropsychiatry syndrome (PANS/PANDAS) and yields testable predictions on pathway activity and barrier permeability. It also motivates targeted interventions that modulate mTOR-related processes in immune and endothelial compartments and within neural circuits in children. So, this article aims to outline a mechanistic framework linking infection-driven mTOR activation to post-infectious neuropsychiatric syndromes.

Source: Fronticelli Baldelli G, Buonsenso D. Proposed Mechanistic Axis of Infections and mTOR Hyperactivation: A Multidisciplinary Review of Immune, Rheumatologic, and Psychiatric Links. Children (Basel). 2025 Nov 25;12(12):1603. doi: 10.3390/children12121603. PMID: 41462744. https://www.mdpi.com/2227-9067/12/12/1603 (Full text)

Evaluation of an online patient education program for children and young people with ME/CFS and their parents within the BAYNET FOR MECFS Study

Abstract:

Background: ME/CFS (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome) poses challenges for affected children and young people (CYP) and their parents. There is often a lack of knowledge about the illness. Education programs can help address this by providing knowledge and supporting the independent management of the condition. For this reason, two online education programs – one for affected CYP and one for their parents – were developed, implemented, and evaluated in terms of acceptance, format, and benefits.

Methods: 24 CYP aged of up to 20 years with ME/CFS and their parents were recruited for this study. Of these 22 CYP with ME/CFS and 20 parents participated in the online education program. After development and conduction of the programs, six affected CYP were interviewed using written questions, which were answered via an audio device. Furthermore, 6 semi-structured interviews were obtained with parents. All parents also received an online questionnaire to evaluate the program. Data were analyzed using both quantitative and qualitative methods.

Results: Both CYP and their parents expressed overall satisfaction with the program highlighting aspects such as knowledge acquisition or reinforcement and, importantly, the opportunity to connect with other affected CYP or their parents. The online format was also perceived very positively.

Discussion: The online education program met the expectations and needs of both affected CYP and parents regarding content and format. It facilitated exchange and provided practical knowledge. In this format, the online program appears to be a valuable component of care for those affected.

Source: Keicher F, Thomann J, Erlenwein J, Schottdorf M, Wiejaczka K, Reiter NL, Scholz-Schwärzler N, Vogel B, Stojanov S, Augustin S, Saramandic M, Dettmer K, Englbrecht S, Jaeschke R, Schanz L, Dodel V, Zipper C, Schieweck N, Ernst G, Behrends U, Spiegler J. Evaluation of an online patient education program for children and young people with ME/CFS and their parents within the BAYNET FOR MECFS Study. Neuropediatrics. 2025 Dec 23. doi: 10.1055/a-2773-9655. Epub ahead of print. PMID: 41435903. https://www.thieme-connect.com/products/ejournals/abstract/10.1055/a-2773-9655 (Full text available as PDF file)

Pediatric Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Diagnostic and Communication Case Study for Health Care Providers in Training

Abstract:

Introduction: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic, complex illness. No diagnostic tests exist; illness evaluation relies on medical history, physical exam, and laboratory tests. While more is known about ME/CFS in adults, it can affect children and adolescents as a chronic condition.

Methods: We implemented an ME/CFS pediatric educational activity (diagnosis, management, and communication) with medical, physician assistant, and nursing students at one university and with medical students at a second university. Pretests, two videos and slides, and posttests were completed in approximately 40 minutes. Evaluation included quantitative and qualitative measures for knowledge, attitudes, beliefs, confidence, and clinical information about ME/CFS.

Results: The first group included 31 students who reported low familiarity and clinical exposure to ME/CFS. At posttest, 25 students (81%) recognized ME/CFS as a medical condition compared to seven (23%) at pretest. Using 0-5 scales, mean pretest-to-posttest ability to diagnose increased from 1.0 to 3.5, and confidence to communicate increased from 1.4 to 3.9. The second group, including 26 students pretest and 19 posttest, also reported low familiarity and clinical exposure The posttest showed increased self-rated ability to diagnose (pretest M: 0.6, posttest M: 3.3) and confidence to communicate (pretest M: 1.4, posttest M: 3.7). Qualitative feedback for this group showed understanding of pediatric ME/CFS symptoms, management, and communication.

Discussion: This educational activity increased knowledge of ME/CFS as self-reported ability to make a diagnosis and increased confidence to communicate about pediatric ME/CFS. Participating students showed changes in attitudes towards ME/CFS as a medical condition.

Source: Brimmer DJ, Lin JS, Selinger HA, Issa A, Fall EA, Unger ER. Pediatric Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Diagnostic and Communication Case Study for Health Care Providers in Training. MedEdPORTAL. 2025 Mar 14;21:11507. doi: 10.15766/mep_2374-8265.11507. PMID: 40092054; PMCID: PMC11906784. https://pmc.ncbi.nlm.nih.gov/articles/PMC11906784/ (Full text)