Acoustic Characteristics of Stridor in Multiple System Atrophy.
Nocturnal stridor is a breathing disorder prevalent in patients with multiple system atrophy (MSA). An improved understanding of this breathing disorder is essential since nocturnal stridor carries a poor prognosis (an increased risk of sudden death). In this study, we aimed to classify types of stridor by sound analysis and to reveal their clinical significance. Patients who met the criteria for probable MSA and had undergone polysomnography (PSG) were recruited. Patients were then assessed clinically with sleep questionnaires, including the Pittsburgh Sleep Quality Index, and the Hoehn and Yahr scale. Nocturnal stridor and snoring were analyzed with the Multi-Dimensional Voice Program. Nocturnal stridor was recorded in 22 patients and snoring in 18 patients using the PSG. Waveforms of stridors were classified into rhythmic or semirhythmic after analysis of the oscillogram. Formants and harmonics were observed in both types of stridor, but not in snoring. Of the 22 patients diagnosed with stridor during the present study, fifteen have subsequently died, with the time to death after the PSG study being 1.9 ± 1.4 years (range 0.8 to 5.0 years). The rhythmic waveform group presented higher scores on the Hoehn and Yahr scale and the survival outcome of this group was lower compared to the semirhythmic waveform group (p = 0.030, p = 0.014). In the Kaplan Meier's survival curve, the outcome of patients with rhythmic waveform was significantly less favorable than the outcome of patients with semirhythmic waveform (log-rank test, p < 0.001). Stridor in MSA can be classified into rhythmic and semirhythmic types and the rhythmic component signifies a poorer outcome.
Department of Neurology, Seoul National University Boramae Hospital, Seoul, South Korea.
Dae Lim
DL
Koo
Department of Neurology, Seoul National University Boramae Hospital, Seoul, South Korea.
Jee Young
JY
Lee
Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Samsung Biomedical Research Institute, Seoul, South Korea.|Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, South Korea.
Eun Yeon
EY
Joo
Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Samsung Biomedical Research Institute, Seoul, South Korea.
Seung Bong
SB
Hong
Department of Neurology, Seoul National University Boramae Hospital, Seoul, South Korea.
Hyunwoo
H
Nam
D000162:Acoustics; D000368:Aged; D045422:Continuous Positive Airway Pressure / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000503:physiopathology*; D017286:Polysomnography / Q000379:methods; D012135:Respiratory Sounds / Q000175:diagnosis* / Q000503:physiopathology*; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000503:physiopathology; D012913:Snoring / Q000175:diagnosis / Q000503:physiopathology