An interventional study of transcutaneous vagus nerve stimulation and transcutaneous vagus nerve stimulation in Post-COVID / Long-COVID and ME/CFS, sponsored by University of Luxembourg. Active, not recruiting at 1 site in Luxembourg. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2025-08-08.
Sponsored by University of Luxembourg · Not applicable, Interventional, and Treatment
This study is testing whether a gentle electrical stimulation of a nerve in the ear, called the vagus nerve, can help reduce fatigue and improve symptoms in people with Post-COVID Syndrome or Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). The treatment, known as transcutaneous auricular vagus nerve stimulation (taVNS), is non-invasive and can be done at home using a small device.
Participants will try two different types of stimulation, called Intervention A and Intervention B, to see which may be more effective. Each intervention lasts 4 weeks and will be separated by a break of at least 4 weeks.
Participants will use the device at home twice a day for 30 minutes. Fatigue, quality of life, sleep, and daily activity will be tracked through surveys and wearable devices. All parts of the study-including check-ins and data collection-will be done remotely.
The goal is to learn whether this type of at-home nerve stimulation can safely improve symptoms in people with Post-COVID Syndrome or ME/CFS.
The STIMPACT study is a single-blind, randomized, controlled crossover trial designed to evaluate the efficacy of transcutaneous auricular vagus nerve stimulation (taVNS) in alleviating fatigue and autonomic dysfunction symptoms in individuals diagnosed with Post-COVID Syndrome or Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).
Participants will undergo two distinct intervention phases, referred to as Intervention A and Intervention B, each lasting four weeks and separated by a washout period of at least four weeks to minimize potential carryover effects. The order of interventions will be randomized for each participant.
During each intervention phase, participants will self-administer 30-minute stimulation sessions twice daily using a portable device designed for home use. Adherence to the stimulation protocol will be monitored through device usage logs and regular virtual check-ins with the research team.
The primary outcome measure is the change in fatigue levels, assessed using validated instruments such as the Fatigue Severity Scale (FSS) and the Chalder Fatigue Questionnaire, alongside daily symptom tracking through electronic diaries. Secondary outcomes include assessments of quality of life (SF-36, Bell's Disability Scale), post-exertional malaise (DePaul Symptom Questionnaire - Post-Exertional Malaise subscale), autonomic function (heart rate variability metrics), sleep quality (Pittsburgh Sleep Quality Index), daytime sleepiness (Epworth Sleepiness Scale), mood (Hospital Anxiety and Depression Scale), and physical activity levels (measured via actigraphy).
Data collection will occur at baseline, mid-intervention, post-intervention, and during a follow-up period, utilizing online surveys, virtual consultations, and data synchronization from wearable devices. Statistical analyses will employ mixed-model approaches to evaluate changes in outcome measures over time and between interventions, with subgroup analyses comparing responses between the Post-COVID Syndrome and ME/CFS cohorts.
This study aims to provide robust evidence on the potential benefits of taVNS as a non-invasive, home-based therapeutic option for managing fatigue and autonomic dysfunction in these patient populations.
604 studies on the registry are indexed under Post-Acute COVID-19 Syndrome; 201 are open to participants now.
This study's planned enrollment of 48 is below the median of 60 across 416 interventional studies indexed under Post-Acute COVID-19 Syndrome.
Browse Post-Acute COVID-19 Syndrome studies →University of Luxembourg is the lead sponsor of 5 studies on the registry; 2 are open to participants now.
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Participants in this arm will receive stimulation applied to the cymba conchae of the left ear, twice daily for 30 minutes over a 4-week period. This location is known to be innervated by the auricular branch of the vagus nerve. All participants will be trained in device use and electrode placement. Adherence will be tracked via device logs and virtual check-ins.
Device: transcutaneous vagus nerve stimulation
Participants in this arm will receive stimulation applied to the earlobe, a site not innervated by the vagus nerve, under the same schedule: twice daily for 30 minutes over a 4-week period. The procedure, device appearance, and instructions are identical to the active condition to maintain participant blinding. Adherence is tracked identically.
Device: transcutaneous vagus nerve stimulation
Transcutaneous auricular vagus nerve stimulation (taVNS) delivered using the CE-certified tVNS® device (tVNS Technologies GmbH). Stimulation parameters include a pulse width of 250-500 μs, frequency of 10-25 Hz, and an individually titrated intensity (typically up to 5 mA). The device operates with a 20-50% duty cycle and is used at home.
Also known as: vagus stimulation, tVNS, taVNS
Sham stimulation using the same CE-certified tVNS® device. Electrode placement is on the earlobe, which lacks vagus nerve innervation. Stimulation parameters (pulse width, frequency, intensity, duty cycle) mirror those of the active condition, with intensity adjusted to perceptual threshold to mimic the sensation of real stimulation and preserve blinding.
Also known as: taVNS, Vagus stimulation, tVNS
Fatigue
Reduction in fatigue measured by the Fatigue Severity and Chalder Fatigue Scales. The FSS is a 9-item scale that measures the severity of fatigue and how much it affects the person's activities and lifestyle in patients with a variety of disorders. The items are scored on a 7 point scale with 1=strongly disagree and 7=strongly agree. The minimum score=9 and maximum score possible=63. Higher the score=greater fatigue severity. More common way of scoring: mean of all the scores with minimum score being 1 and maximum score being 7. The Chalder Fatigue Scale consists of 11 items scored on a 4-point Likert scale (0 to 3). Higher total scores reflect a greater degree of fatigue.
Time frame: From baseline to end of treatment at 4 weeks.
Patient Health (Quality of life)
Improvements in quality of life, assessed by the Short Form Health Survey (SF-36). The SF-36 is a 36-item scale constructed to survey health status and quality of life (Ware \& Sherbourne, 1992). Each item is scored on a 0 to 100 range so that the lowest and highest possible scores are 0 and 100, respectively. Greater scores indicate greater functioning.
Time frame: From baseline to end of treatment at 4 weeks.
Patient Health (Ability)
Assessment of functional ability/disability using the Bell CFIDS disability scale (Bell Score). Scores from 0 to 100, lower score indicating greater disability.
Time frame: From baseline to end of treatment at 4 weeks.
Post-Exertional Malaise (PEM)
PEM measured by the DePaul Symptom Questionnaire - Post-Exertional-Malaise Subscale (DSQ-PEM)
Time frame: From baseline to end of treatment at 4 weeks.
Autonomic Function
Autonomic function evaluated through Heart Rate Variability (HRV)
Time frame: From baseline to end of treatment at 4 weeks.
Sleep Quality
Assessed by the Pittsburgh Sleep Quality Index (PSQI) and daily E-Diary entries.
Time frame: From baseline to end of treatment at 4 weeks.
Sleepiness
Measured by the Epworth Sleepiness Scale (ESS). Scores from 0 to 24: 0-5 lower normal daytime sleepiness 6-10 normal daytime sleepiness 11-12 mild daytime symptoms 13-15 moderate daytime symptoms 16-24 severe daytime symptoms
Time frame: From baseline to end of treatment at 4 weeks.
Depression and Anxiety
Evaluated using the Hospital Anxiety and Depression Scale (HADS). The HADS consists of 14 questions that can be scored from 0 to 3. Seven questions relate to anxiety (indicated by an 'A') and 7 questions relate to depression (as shown by a 'D'). 0-7 = Normal; 8-10 = Borderline abnormal (borderline case); 11-21 = Abnormal (case).
Time frame: From baseline to end of treatment at 4 weeks.
Patients Activity
monitored through actigraphy (i.e. step count)
Time frame: From baseline to end of treatment at 4 weeks.
Plan to share: Undecided
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Started Jul 2025 (actual). Primary completion is estimated for Oct 2026, 15 months after the start.
Of 233 non-industry interventional studies with no phase under Post-Acute COVID-19 Syndrome, half reached primary completion within 16 months of starting (the median), counting those still running; a quarter within 8 and three quarters within 28. This study's planned 15 months is close to that.
Counting every sponsor, half of 244 studies reached it within 16 months; a quarter within 7 and three quarters within 27.
How these figures are worked out, and which studies are left out of them.
This study is active, not recruiting, as verified in Jul 2025. You cannot join it, but the record below documents what was studied.
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University of Luxembourg