Myasthenia GravisCAPTURE - MGNCT06743490
Capturing Key MG-symptoms Using Smartphone Recordings.
An observational study of Myasthenia Gravis and Fatigue, run by Leiden University Medical Center at 2 sites in Netherlands.
Trial summary
This study will make use of a cross-sectional design of MG patients and non-MG participants to quantitatively assess key MG symptoms, and to explore the applicability of machine learning algorithms to their measurement. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Myasthenia Gravis, Fatigue
- How many people
- 225 participants
- Where
- 2 sitesNetherlands
- Study dates
- 18 Mar 2025to 30 Sep 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: We aim to include 150 patients with Myasthenia Gravis, recruited from the national Dutch-Belgia MG registry, the patient organisation 'Spierziekten Nederland' or identified by the clinical team of Leiden University Medical Center (LUMC). Non-MG participants are preferentially sampled from friends and family of enrolled MG patients. The highest preference will be same-household family members, lowest preference will be non-household non-family members. This acts as both a natural source of control participants and a natural control for any environmental confounders. Furthermore, non-MG participants will be recruited separately by placing flyers in crowded areas in the LUMC.
Who may be able to join
- Age ≥ 18 years
- Ability to understand the requirements of the study and provide written informed consent.
- A clinical diagnosis of myasthenia gravis (ocular or generalized) as defined by the Dutch national guideline (category "definite" or "probable" MG).
- MGFA Clinical Classification of disease severity I-IV.
- Subjects have at least one of the symptoms of interest (namely dysarthria, dysphonia, proximal arm fatigue and/or ptosis).
- Subjects are not diagnosed with and have no clinical suspicion of MG.
- Subjects do not have a medical history of any of the symptoms of interest (namely dysarthria, dysphonia, proximal arm fatigue and/or ptosis).
Who cannot join
- Not willing to be audio-recorded for the study assessments.
- Not willing to be video-recorded for the study assessments.
- Subjects currently taking part in a clinical trial of an Investigational Medicinal Product.
- Subjects who have used an immediate release pyridostigmine-based medication in the 12 hours prior to their participation and participants on prolonged release pyridostigmine.
- Subjects have cognitive or physical limitations that, in the opinion of the investigator, limits the subject's ability to complete study procedures/
- Subjects with an upper-limb amputation or who are non-verbal.
- Subjects with a diagnosed neurological disease resulting in muscle weakness, other than MG.
- 1. Limitation of upper limb mobility or speech impairment of any cause.
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Netherlands2 sites, 2 recruiting
- Not yet recruiting
Leiden University Medical Center
Leiden, South Holland, 2333 ZA
Martijn R Tannemaat, MD PhD, +31715262197, m.r.tannemaat@lumc.nl
Yvonne JM Campman, MD, +31715262118, y.j.m.campman@lumc.nl
- Recruiting
Leiden University Medical Center
Leiden
Martijn R Tannemaat, MD, PhD, +31715262118, m.r.tannemaat@lumc.nl
Yvonne JM Campman, MD, +31715262118, y.j.m.campman@lumc.nl
About this study
Official title: Capturing Key Symptoms Using Smartphone Recordings in Patients With Myasthenia Gravis (CAPTURE-MG)
This study will make use of a cross-sectional design of MG patients and non-MG participants to quantitatively assess key MG symptoms, and to explore the applicability of machine learning algorithms to their measurement.
Read the detailed description
Due to the cross-sectional design, participants will only have to visit Leiden University Medical Center (LUMC) once. For patients already treated in the LUMC, we will try to align this visit with a standard clinical appointment.
After inclusion, all baseline data, consisting of demographics, clinical history and a number of questionnaires (four for MG participants, three for non-MG participants), will be collected. The symptom-specific assessments are performed in a standard order, with the most fatiguing task (i.e. proximal arm fatigue static assessment) last. We estimate the visit will take a total of 60 minutes.
This study is considered to be low risk. Withholding pyridostigmine for a limited period is part of standard care of MG (before investigations or clinical assessments) and does not affect long term clinical outcome. MG participants will consent to withhold pyridostigmine for 12 hours prior to the study visit if they are on this treatment and restart it after the visit. As this is a non-interventional, observational study where only questionnaire-based and non-contact digital data are being collected, the only source of marginal risk relates to data protection and confidentiality, including arrangements for the transfer and storage of data. Given it would not be possible to deidentify the digital audio or video data while maintaining the requisite integrity for data analysis, we will seek explicit consent for the sharing of this information in this identifiable format.
- Conditions
- Myasthenia Gravis, Fatigue
- Keywords
- Myasthenia Gravis, Fatigue, Digital features, Machine Learning Algorithms, Dysarthria, Dysphonia, Proximal arm fatigue, Ptosis
- Medical subject headings
- Myasthenia Gravis, Fatigue, Dysarthria, Dysphonia, Blepharoptosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| MG patients | MG patients with at least one of the symptoms of interest (i.e. dysarthria, dysphonia, proximal arm fatigue and/or ptosis). We aim to include 150 patients with Myasthenia Gravis. | |
| Non-MG participants | Non-MG participants that do not have a medical history of any of the symptoms of interest. We aim to include 75 controls. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Differentiating between MG-patients and non-MG participants using digital features of dysarhtria, dysphonia, proximal arm fatigue and ptosis.
Using machine-learning algorithms.
Measured: Assessed at a single time point during outpatient visit
Secondary outcomes (6)
Correlating digital features of dysarthria, dysphonia, proximal arm fatigue and ptosis in MG patients with disease severity as measured by the MGC score.
Myasthenia Gravis Composite (MGC) is scored on an ordinal scale with four possible categories and weighted and consists of 10 items with a total score of 0-50; a higher score indicating more severe disease.
Measured: Assessed at a single time point during outpatient visit
Correlating digital features of dysarthria, dysphonia, proximal arm fatigue and ptosis in MG patients with the impact of MG on daily activities as measured by the MG-ADL.
MG Activities of Daily Living (MG-ADL) consists of 8 items with a total score of 0-24; a higher score indicating more severe disease.
.
Measured: Assessed at a single time point during outpatient visit
The performance of automated signal processing of speech recordings collected through smartphone microphone for detection of dysarthria and dysphonia compared to clinical assessment.
Clinical assessment by two independent trained speech and language pathologists (SLP) using the Therapy Outcome Measure scale (TOMS) for dysarthria and GRBAS scale (Grade, Roughness, Breathiness, Asthenia and Strain) for dysphonia.
Measured: Assessed at a single time point during outpatient visit
The performance of automated measurement of proximal arm-fatiguing exercises through computer vision techniques applied to smartphone camera recordings for detection of proximal arm muscle weakness and fatigability compared to clinical assessment.
Clinical assessment by accredited clinicans.
Measured: Assessed at a single time point during outpatient visit
The performance of automated measurement of ptosis-provoking exercises through computer vision techniques applied to smartphone camera recordings for detection of ptosis compared to clinical assessment.
Clinical assessment by accredited clinicians.
Measured: Assessed at a single time point during outpatient visit
Correlating digital features of dysarthria, dysphonia, proximal arm fatigue and ptosis in MG patients with their level of fatigue as measured by the CIS-fatigue subscale.
Checklist Individual Strength (CIS-) fatigue subscale consists of 8 questions on fatigue experienced during the previous 2 weeks. Each question is scored on a 7-point Likert scale and a score ≥ 35 indicates severe fatigue. A higher score means more severe fatigue. The total score of the fatigue subscale ranges from 8-56 (the total score of the CIS questionnaire ranges from 20-140).
Measured: Assessed at a single time point during outpatient visit
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Dec 2024
- Study start18 Mar 2025
- Primary completion28 Aug 2026 (estimated)
- Study completion30 Sep 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Myasthenia GravisStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Enrolment
- 225 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Leiden University Medical Center
- Sponsor type
- University, hospital or other
- Collaborators
- Huma
- Responsible party
- Principal investigator, Martijn R. Tannemaat, MD PhD, Leiden University Medical Center
- Investigators
- Martijn R. Tannemaat, MD, PhD, Principal investigator, Leiden University Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06743490
- Sponsor's protocol ID
- NL86693.058.24
- Acronym
- CAPTURE - MG
- Status last verified
- Jul 2026
- First submitted
- 9 Dec 2024
- Last updated
- 8 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 8 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Capturing Key Symptoms Using Smartphone Recordings in Patients With Myasthenia Gravis (CAPTURE-MG)
- ClinicalTrials.gov ID
- NCT06743490
- Acronym / sponsor ID
- CAPTURE - MG / NL86693.058.24
- Conditions
- Myasthenia Gravis, Fatigue
- Keywords
- Myasthenia Gravis, Fatigue, Digital features, Machine Learning Algorithms, Dysarthria, Dysphonia, Proximal arm fatigue, Ptosis
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 225 participants (estimated)
- Lead sponsor
- Leiden University Medical CenterUniversity, hospital or other
- Collaborators
- Huma
- Study start
- 18 Mar 2025 (actual)
- Primary completion
- 28 Aug 2026 (estimated)
- Study completion
- 30 Sep 2026 (estimated)
- First posted
- 20 Dec 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study will make use of a cross-sectional design of MG patients and non-MG participants to quantitatively assess key MG symptoms, and to explore the applicability of machine learning algorithms to their measurement.
Detailed description
Due to the cross-sectional design, participants will only have to visit Leiden University Medical Center (LUMC) once. For patients already treated in the LUMC, we will try to align this visit with a standard clinical appointment.
After inclusion, all baseline data, consisting of demographics, clinical history and a number of questionnaires (four for MG participants, three for non-MG participants), will be collected. The symptom-specific assessments are performed in a standard order, with the most fatiguing task (i.e. proximal arm fatigue static assessment) last. We estimate the visit will take a total of 60 minutes.
This study is considered to be low risk. Withholding pyridostigmine for a limited period is part of standard care of MG (before investigations or clinical assessments) and does not affect long term clinical outcome. MG participants will consent to withhold pyridostigmine for 12 hours prior to the study visit if they are on this treatment and restart it after the visit. As this is a non-interventional, observational study where only questionnaire-based and non-contact digital data are being collected, the only source of marginal risk relates to data protection and confidentiality, including arrangements for the transfer and storage of data. Given it would not be possible to deidentify the digital audio or video data while maintaining the requisite integrity for data analysis, we will seek explicit consent for the sharing of this information in this identifiable format.
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| MG patients | – | –MG patients with at least one of the symptoms of interest (i.e. dysarthria, dysphonia, proximal arm fatigue and/or ptosis). We aim to include 150 patients with Myasthenia Gravis. |
| Non-MG participants | – | –Non-MG participants that do not have a medical history of any of the symptoms of interest. We aim to include 75 controls. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- We aim to include 150 patients with Myasthenia Gravis, recruited from the national Dutch-Belgia MG registry, the patient organisation 'Spierziekten Nederland' or identified by the clinical team of Leiden University Medical Center (LUMC). Non-MG participants are preferentially sampled from friends and family of enrolled MG patients. The highest preference will be same-household family members, lowest preference will be non-household non-family members. This acts as both a natural source of control participants and a natural control for any environmental confounders. Furthermore, non-MG participants will be recruited separately by placing flyers in crowded areas in the LUMC.
Key inclusion criteria (7 listed)
- Age ≥ 18 years
- Ability to understand the requirements of the study and provide written informed consent.
- A clinical diagnosis of myasthenia gravis (ocular or generalized) as defined by the Dutch national guideline (category "definite" or "probable" MG).
- MGFA Clinical Classification of disease severity I-IV.
- Subjects have at least one of the symptoms of interest (namely dysarthria, dysphonia, proximal arm fatigue and/or ptosis).
Key exclusion criteria (8 listed)
- Not willing to be audio-recorded for the study assessments.
- Not willing to be video-recorded for the study assessments.
- Subjects currently taking part in a clinical trial of an Investigational Medicinal Product.
- Subjects who have used an immediate release pyridostigmine-based medication in the 12 hours prior to their participation and participants on prolonged release pyridostigmine.
- Subjects have cognitive or physical limitations that, in the opinion of the investigator, limits the subject's ability to complete study procedures/
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Differentiating between MG-patients and non-MG participants using digital features of dysarhtria, dysphonia, proximal arm fatigue and ptosis.
Time frame: Assessed at a single time point during outpatient visit
Using machine-learning algorithms.
6 secondary outcomes
Correlating digital features of dysarthria, dysphonia, proximal arm fatigue and ptosis in MG patients with disease severity as measured by the MGC score.
Time frame: Assessed at a single time point during outpatient visit
Correlating digital features of dysarthria, dysphonia, proximal arm fatigue and ptosis in MG patients with the impact of MG on daily activities as measured by the MG-ADL.
Time frame: Assessed at a single time point during outpatient visit
The performance of automated signal processing of speech recordings collected through smartphone microphone for detection of dysarthria and dysphonia compared to clinical assessment.
Time frame: Assessed at a single time point during outpatient visit
The performance of automated measurement of proximal arm-fatiguing exercises through computer vision techniques applied to smartphone camera recordings for detection of proximal arm muscle weakness and fatigability compared to clinical assessment.
Time frame: Assessed at a single time point during outpatient visit
The performance of automated measurement of ptosis-provoking exercises through computer vision techniques applied to smartphone camera recordings for detection of ptosis compared to clinical assessment.
Time frame: Assessed at a single time point during outpatient visit
Correlating digital features of dysarthria, dysphonia, proximal arm fatigue and ptosis in MG patients with their level of fatigue as measured by the CIS-fatigue subscale.
Time frame: Assessed at a single time point during outpatient visit
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Jul 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Martijn R. Tannemaat, MD, PhD principal investigator
Leiden University Medical Center
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Myasthenia Gravis and Fatigue, run by Leiden University Medical Center at 2 sites in Netherlands.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 8 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Netherlands. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Martijn R Tannemaat, MD, PhD (+31715262197, m.r.tannemaat@lumc.nl), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Differentiating between MG-patients and non-MG participants using digital features of dysarhtria, dysphonia, proximal arm fatigue and ptosis. (time frame: Assessed at a single time point during outpatient visit). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Jul 2026.