Isolated stridor without any other sleeping breathing disorder diagnosed using drug-induced sleep endoscopy in a patient with multiple system atrophy: A case report

RATIONALE: Multiple system atrophy (MSA) is a rare neurodegenerative disease characterized by Parkinsonism and autonomic dysfunction or cerebellar ataxia. MSA can be accompanied by stridor caused by laryngeal stenosis secondary to vocal cord dysfunction. PATIENT CONCERN: A 60-year-old woman with MSA, complaining of difficulty in breathing during sleep. Her bed partner reported witnessing grunting-like sounds during sleep. DIAGNOSIS: Isolated stridor without any other sleeping breathing disorder diagnosed using drug-induced sleep endoscopy (DISE) in a patient with MSA. INTERVENTIONS: On polysomnography, there was no obstructive sleep apnea. Using DISE, abnormally adducted vocal cords during inspiratory respiration were identified, leading to a diagnosis of stridor. We prescribed positive airway pressure to resolve the stridor. OUTCOME: Our patient was also prescribed continuous positive airway pressure for the treatment of nocturnal stridor, and it is improved. LESSONS: In summary, when MSA patients present with nocturnal stridor, it is important to evaluate the exact diagnosis and cause of stridor in patients by confirming the movement of vocal cords using DISE, as well as polysomnography.