This chapter discusses the case of a 54-year-oldwoman with disturbing respiratory noise during nocturnal sleep. It presents the clinical history, examination, follow-up, treatment, diagnosis, and the results of the procedures performed on the patient. EMG investigation of laryngeal muscle activity was subsequently performed during wakefulness and sleep, placing fine-wire electrodes in the posterior cricoarytenoid, cricothyroid and thyroarytenoid muscles. The specialist made a diagnosis of nocturnal inspiratory stridor based on the characteristics of the noise present only during sleep, particularly during NREM sleep. A diagnosis of REM-sleep behavior disorder (RBD) was also made due to the characteristic clinical history of violent motor behaviors during sleep associated with polysomnography (PSG) evidence of REM sleep without atonia. Tracheostomy and continuous positive airway pressure (CPAP) are effective treatments of stridor; however, they do not always prevent death in multiple-system atrophy.