[A case report of Parkinson's disease presenting with recurrent dyspneic attacks due to focal laryngeal dystonia].

A 69-year-old woman suffering from Parkinson's disease for 22 years was admitted because of frequent occurrence of paroxysmal dyspnea for 3 months. Her dyspneic attacks consisting of inspiratory stridor and cyanosis occurred mainly during the wearing-off time and continued for less than 30 min. During nonictal period her respiration and phonation were normal and endoscopic investigation of the vocal cord and upper respiratory tract revealed no abnormality. Based on these findings, she was diagnosed to have focal laryngeal dystonia. The 24-hr monitoring with pulseoxymeter recorded frequent occurrence of paroxysmal asymptomatic hopoxemia during both daytime and sleep. With the treatment of tracheostomy and the reduction and alteration of anti-Parkinsonian drugs, dyspneic attacks disappeared gradually. We also confirmed the complete disappearance of paroxysmal asymptomatic hopoxemia with the 24-hr monitoring by pulseoxymeter, which is considered to be a useful method for early detection of asymptomatic focal laryngeal dystonia.