MRI of eye muscles in myasthenia gravis

Recruitment & Eligibility

Status: Recruiting

Sex: Not specified

Target Recruitment: 130

Inclusion Criteria

Recently diagnosed MG patients
- Definitive diagnosis of MG defined as the presence of serum autoantibodies (anti—acetylcholine receptor [AChR],
anti-muscle specific tyrosine kinase [MUSK])
- Start of symptoms was less than a year ago
- No corticosteroid treatment received in the past year
- No TSH-receptor auto-antibodies, no laboratory signs of thyroid dysfunction (T4, TSH), Chronic MG patients
- Definitive diagnosis of MG, defined as described above
- Persisting symptoms of diplopia
- Start of symptoms was more than a year ago
- No TSH-receptor auto-antibodies, no laboratory signs of thyroid dysfunction (T4, TSH), Seronegative MG
patients
- Clinical diagnosis of MG with asymmetric, fluctuating and fatigable muscle weakness and at least one abnormal
neurophysiological test, indicative of neuromuscular dysfunction (repetitive nerve stimulation or single fiber EMG)
- No serum autoantibodies (anti—acetylcholine receptor [AChR], anti-muscle specific tyrosine kinase [MuSK])
- No TSH-receptor auto-antibodies, no laboratory signs of thyroid dysfunction (T4, TSH)

Healthy controls
- No symptoms of diplopia
- No ophthalmopathy
- No prior systemic treatment with corticosteroids, Patient controls: Graves' orbitopathy
- Definitive diagnosis of Graves' orbitopathy, Patient controls: Other neuromuscular disease
- Definitive diagnosis of a neuromuscular disease other than Myasthenia gravis

Exclusion Criteria

- Subjects who are not legally capable
- Subjects under the age of 18
- Contraindications to MRI scanning, including:
o Claustrophobia
o Pregnancy
o Pacemakers and defibrillators
o Nerve stimulators
o Intracranial clips
o Metallic fragments
o Cochlear implants
o Ferromagnetic implants
o Hydrocephalus pump
o Permanent make-up
o Tattoos above the shoulders
o Piercings (unless they can be removed)
o Subjects who cannot keep their head still (eg. Tremor, Parkinson's disease)
o Severe physical restriction (completely wheelchair dependent)
? In the case of uncertainty about the MRI-contraindications, the MR-safety commission of the radiology
department will decide whether this subject can be included in the study or not.

Study & Design

Study Type: Observational non invasive

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
(1) QMRI parameters (muscle fat fraction, muscle inflammation, muscle volume) which are hypothesized to differ between MG<br>patients and the healthy/disease controls for diagnostic value.<br>(2) For the second objective comparing recently diagnosed and chronic MG patients for exploring the pathophysiology

Secondary Outcome Measures

Name	Time	Method
(3) For the third objective comparing the gMRI parameters in time in the recently diagnosed MG group to measures of severity of<br>disease to assess the predictive value for treatment response.<br>(4) For the fourth objective comparing gMRI parameters to functional measures in all groups for exploring the relationship with the<br>symptoms