Prevalence of Laryngeal Dysfunction and Otolaryngology Intervention Among Myasthenia Gravis Patients

Introduction: Myasthenia gravis (MG) is a rare condition that can have laryngeal involvement. Knowledge of the frequency of laryngeal symptoms and the involvement of speech-language pathologists (SLP) and otolaryngologists (ENT) in evaluating these symptoms is poorly understood.

Methods: We utilized the TriNetX research network – a collection of deidentified records of 83 Health Care Organizations and over 98 million patients – to investigate laryngeal symptoms of MG in adults (over 18 years) and SLP/ENT involvement in treatment. Virtual visits were utilized as an index event to compare prevalence of symptoms between a cohort with MG and without MG after propensity score matching for demographics and gastro-esophageal reflux disorder. Finally, percent of all MG patients with laryngeal symptoms undergoing voice and swallow evaluation and therapy was explored.

Results: Prevalence of diagnosed aspiration pneumonia, dysarthria, dysphonia, and dysphagia were 3.6%, 8.4%, 4.1%, and 23.8%, respectively in the MG group (n = 3,482) and 0.6%, 0.4%, 1.1%, and 4.1% in the no MG group (n = 2,319,800), respectively. After propensity score matching (n = 3,474 per group), risk difference between MG and no MG group (% [95%CI]) was 2.5% [1.80-3.21%] for aspiration pneumonia, 7.8% [6.85-8.76%] for dysarthria, 2.33% [1.55-3.11%] for dysphonia, and 16.98% [15.34-18.63] for dysphagia. Among all MG patients, 3.2% had voice evaluation, 10.8% had swallow evaluation, 1.7% had voice therapy, and 4.7% had swallow therapy. Among those with documented dysarthria, dysphonia, and/or dysphagia, 9.7% had had voice evaluation, 34.3% had swallow evaluation, 5.8% had voice therapy, and 15.5% had swallow therapy.

Conclusions: Individuals with MG are more likely to have aspiration pneumonia, dysarthria, dysphonia, and dysphagia, but few receive voice or swallow evaluation and therapy. Given the quality-of-life implications of voice disorders and the morbidity associated with dysphagia, the additional risk of developing these symptoms provides evidence that laryngologists should more frequently be included as part of a team to care for individuals with MG.