2004 Volume 16 Issue 2 Pages 139-144
Bilateral vocal cord abductor paralysis (VCAP) is frequently associated with multiple system atrophy (MSA). The early clinical manifestation of VCAP is nocturnal inspiratory stridor simulating heavy snoring that is observed in patients with obstructive sleep apnea syndrome. We have observed two cases of respiratory disturbance during sleep due to VCAP caused by MSA. Using laryngofibroptic examination, vocal cord movements were analyzed during wakefulness as well as during sleep induced by intravenous administration of diazepam. In case 1, VCAP was observed not only during wakefulness but also during sleep. In case 2, although VCAP was observed only during sleep, the vocal cords' movement in breathing at rest was normal in the course of wakefulness. As a treatment, continuous positive airway pressure (CPAP) was applied for the respiratory disturbance during sleep. In case 1, apnea-hypopnea index (AHI) as well as the sleep architecture completely recovered and daytime sleepiness improved. In case 2, the sleep architecture became worse despite improvement of the AHI; as a result, treatment by CPAP was given up. These results indicate that CPAP should initially be applied toward the respiratory disturbance during sleep in MSA.
