Sexual and Urinary Dysfunctions in Generalized Myasthenia (MYAOUS)

Sexual and Urinary Dysfunctions in Generalized Myasthenia: Impact on Quality of Life - the MYAOUS Study

Myasthenia gravis is an autoimmune disease caused by specific autoantibodies that disrupt the function of the neuromuscular junction. It manifests as excessive fatigue of the skeletal muscles during physical exertion and affects 15,000 people in France. Initial symptoms are most often ocular (ptosis, diplopia) but can later spread throughout the body, potentially leading in some cases to respiratory failure and/or swallowing difficulties (myasthenic crisis) or even death. This condition is currently being managed more effectively through treatment, and the invisible symptoms (sexual dysfunction, sphincter dysfunction, psychological impact, etc.) may ultimately be more debilitating than the initial symptoms, which are often controlled by maintenance and/or symptomatic treatments. The impact of myasthenia gravis on intimate life remains a taboo subject and is poorly understood by both the medical community and patients. In the literature, only a single article from 2021 addresses sexual dysfunction in patients with myasthenia gravis. Urinary disorders in myasthenia gravis are frequently reported but have also been little studied.

A national survey, conducted using an online questionnaire distributed by patient associations, shed light on the disease's impact on patients' intimate lives. In this study of 190 patients, 46 of them responded to the question about sexual function, and one in two patients reported sexual complaints; in 46% of cases, this disorder significantly impacted the patients' daily lives. In particular, a decrease in the frequency of sexual intercourse with a partner was noted in 55% of cases, as well as a decrease in sexual desire in 51% of cases.

Sexual dysfunction is very common and underreported in many chronic neurological diseases. The Sexual Complaints Screener (SCS W/M) questionnaires for women and men in English have very recently been validated in French (Questionnaires de Plaintes Sexuelles, QPS F/H).

It now have a 10-item self-administered questionnaire that assesses the full range of sexual disorders and their impact.

In conclusion, while the visible symptoms of myasthenia gravis are widely recognized, the invisible symptoms-such as genitourinary and sphincter disorders-remain largely unrecognized and underdiagnosed. It is therefore essential to conduct systematic screening in order to best guide our patients and thereby improve their quality of life.

Study Overview

• Status: Not yet recruiting
• Conditions: Myasthenia Gravis (MG)
• Intervention / Treatment: Other: No intervetion

• Study Type: Observational
• Enrollment (Estimated): 150

Contacts and Locations

• Study Contact: Name: Saskia BRESCH; Phone Number: 04 92 03 83 20; Email: Bresch.s@chu-nice.fr

Study Locations

• France
  • Nice, France, 06000
    • Nice University Hospital
    • Principal Investigator: Saskia Bresch
    • Contact: Saskia BRESCH; Phone Number: 04 92 03 83 20; Email: Bresch.s@chu-nice.fr
  • Paris, France, 75000
    • APHP and Myology institute
    • Contact: BIRNBAUM Simone; Phone Number: 33 1 42 16 58 79; Email: s.birnbaum@institut-myologie.org
    • Principal Investigator: Sophie DEMERET

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Myasthenic patients

Description

Inclusion Criteria:

1. Minimum age of 18 years at the time the informed consent form is obtained.

2. Confirmed diagnosis of generalized autoimmune myasthenia gravis, including at least two of the following:

   1. Typical clinical features assessed by a physician specializing in myasthenia gravis
   2. A decrease of ≥ 10% during repeated nerve stimulation (3-5 Hz) or increased irregularity on a single-fiber electromyogram
   3. A positive edrophonium test or response to anticholinesterase agents
   4. Serum anti-AChR or anti-MuSK antibodies.
3. Enrolled in or covered by a social security program in accordance with current regulations governing research involving human subjects.

Exclusion Criteria:

1. Pregnant (at the time of enrollment)
2. Postpartum < 6 months
3. Severe cognitive impairment or under legal guardianship, making it impossible to understand or complete self-administered questionnaires.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Myasthenic patient with genitourinary and sphincter disorders	Other: No intervetion; no intervention

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Classification of Sexual Dysfunction in Patients with Generalized Autoimmune Myasthenia	The sexual complaints questionnaire (QPS questionnaire) assesses sexual complaints over the past six months-on a scale of 0 to 9	At inclusion

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assessment of Bladder and Sphincter Disorders	Urinary Symptoms Questionnaire score from 0 to 21	at inclusion
Evaluation of Anorectal Disorders	The Neurogenic Bowel Dysfunction Score is a questionnaire used to assess the main digestive symptoms in people with diseases score 0 to 10	at inclusion
The Impact of Myasthenia on Daily Life	Myasthenia Gravis Activities of Daily Living (MG-ADL) questionnaire - score 0 to 24	at inclusion
Impact of Myasthenia Gravis on Quality of Life	The Myasthenia Gravis Quality of Life - 15 items (MGQOL-15) is a myasthenia-specific tool consisting of 15 patient-reported items that assesses the physical, psychological, and social domains commonly affected by myasthenia over the past few weeks	at inclusion
Health-Related Quality of Life impact	Health-Related Quality of Life Questionnaire - measures self-reported health on a scale ranging from 0 to 100	at inclusion
the impact of fatigue on daily life	The quality of life item banks for adults with neurological disorders questionnaire : NeuroQoL Fatigue Short Form is a brief, validated questionnaire that measures the impact of fatigue on the daily lives of patients with neurological disorders and consists of 8 questions	at inclusion

Collaborators and Investigators

• Sponsor: Centre Hospitalier Universitaire de Nice

Study record dates

Study Major Dates

• Study Start (Estimated): July 30, 2026
• Primary Completion (Estimated): July 30, 2030
• Study Completion (Estimated): July 30, 2030

Study Registration Dates

• First Submitted: June 23, 2026
• First Submitted That Met QC Criteria: June 26, 2026
• First Posted (Actual): July 1, 2026

Study Record Updates

• Last Update Posted (Actual): July 1, 2026
• Last Update Submitted That Met QC Criteria: June 26, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Myasthenia gravis; genitourinary and sphincter disorders
• Additional Relevant MeSH Terms: Nervous System Diseases; Neoplasms by Site; Neoplasms; Neuromuscular Diseases; Autoimmune Diseases; Immune System Diseases; Autoimmune Diseases of the Nervous System; Neurodegenerative Diseases; Paraneoplastic Syndromes, Nervous System; Nervous System Neoplasms; Paraneoplastic Syndromes; Neuromuscular Junction Diseases; Myasthenia Gravis
• Other Study ID Numbers: 25-PP-12

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No