Capturing Key MG-symptoms Using Smartphone Recordings. (CAPTURE - MG)

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.

Study Overview

• Status: Recruiting
• Conditions: Fatigue; Myasthenia Gravis

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 Type: Observational
• Enrollment (Estimated): 225

Contacts and Locations

• Study Contact: Name: Martijn R Tannemaat, MD, PhD; Phone Number: +31715262197; Email: m.r.tannemaat@lumc.nl
• Study Contact Backup: Name: Yvonne JM Campman, MD; Phone Number: +31715262118; Email: y.j.m.campman@lumc.nl

Study Locations

• Netherlands
  • Leiden, Netherlands
    • Recruiting
    • Leiden University Medical Center
    • Contact: Yvonne JM Campman, MD; Phone Number: +31715262118; Email: y.j.m.campman@lumc.nl
    • Contact: Martijn R Tannemaat, MD, PhD; Phone Number: +31715262118; Email: m.r.tannemaat@lumc.nl
  • South Holland
    • Leiden, South Holland, Netherlands, 2333 ZA
      • Not yet recruiting
      • Leiden University Medical Center
      • Contact: Yvonne JM Campman, MD; Phone Number: +31715262118; Email: y.j.m.campman@lumc.nl
      • Contact: Martijn R Tannemaat, MD PhD; Phone Number: +31715262197; Email: m.r.tannemaat@lumc.nl
      • Principal Investigator: Martijn R Tannemaat, MD PhD
      • Sub-Investigator: Yvonne JM Campman, MD
      • Sub-Investigator: Jan JGM Verschuuren, MD PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

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.

Description

Inclusion Criteria:

1. Age ≥ 18 years
2. Ability to understand the requirements of the study and provide written informed consent.

Inclusion Criteria for MG participants only:

1. A clinical diagnosis of myasthenia gravis (ocular or generalized) as defined by the Dutch national guideline (category "definite" or "probable" MG).
2. MGFA Clinical Classification of disease severity I-IV.
3. Subjects have at least one of the symptoms of interest (namely dysarthria, dysphonia, proximal arm fatigue and/or ptosis).

Inclusion Criteria for non-MG participants only

1. Subjects are not diagnosed with and have no clinical suspicion of MG.
2. Subjects do not have a medical history of any of the symptoms of interest (namely dysarthria, dysphonia, proximal arm fatigue and/or ptosis).

Exclusion Criteria:

1. Not willing to be audio-recorded for the study assessments.
2. Not willing to be video-recorded for the study assessments.
3. Subjects currently taking part in a clinical trial of an Investigational Medicinal Product.
4. Subjects who have used an immediate release pyridostigmine-based medication in the 12 hours prior to their participation and participants on prolonged release pyridostigmine.
5. Subjects have cognitive or physical limitations that, in the opinion of the investigator, limits the subject's ability to complete study procedures/

Exclusion Criteria for MG participants only:

1. Subjects with an upper-limb amputation or who are non-verbal.
2. Subjects with a diagnosed neurological disease resulting in muscle weakness, other than MG.

Exclusion Criteria for non-MG participants only:

1. Limitation of upper limb mobility or speech impairment of any cause.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
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 the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Differentiating between MG-patients and non-MG participants using digital features of dysarhtria, dysphonia, proximal arm fatigue and ptosis.	Using machine-learning algorithms.	Assessed at a single time point during outpatient visit

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	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. .	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.	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.	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.	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).	Assessed at a single time point during outpatient visit

Collaborators and Investigators

• Sponsor: Leiden University Medical Center
• Collaborators: Huma
• Investigators: Principal Investigator: Martijn R. Tannemaat, MD, PhD, Leiden University Medical Center

Study record dates

Study Major Dates

• Study Start (Actual): March 18, 2025
• Primary Completion (Estimated): April 1, 2026
• Study Completion (Estimated): April 1, 2026

Study Registration Dates

• First Submitted: December 9, 2024
• First Submitted That Met QC Criteria: December 19, 2024
• First Posted (Actual): December 20, 2024

Study Record Updates

• Last Update Posted (Estimated): September 9, 2025
• Last Update Submitted That Met QC Criteria: September 2, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: Fatigue; Myasthenia Gravis; Ptosis; Dysarthria; Dysphonia; Machine Learning Algorithms; Digital features; Proximal arm fatigue
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Neoplasms by Site; Neoplasms; Pathological Conditions, Anatomical; Neuromuscular Diseases; Autoimmune Diseases; Immune System Diseases; Respiratory Tract Diseases; Neurobehavioral Manifestations; Autoimmune Diseases of the Nervous System; Neurodegenerative Diseases; Otorhinolaryngologic Diseases; Paraneoplastic Syndromes, Nervous System; Nervous System Neoplasms; Paraneoplastic Syndromes; Neuromuscular Junction Diseases; Laryngeal Diseases; Communication Disorders; Language Disorders; Speech Disorders; Articulation Disorders; Voice Disorders; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Fatigue; Myasthenia Gravis; Prolapse; Dysarthria; Dysphonia
• Other Study ID Numbers: NL86693.058.24

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No