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Acoustic Characteristics of Stridor in Multiple System Atrophy.

Koo DL, Lee JY, Joo EY, Hong SB, Nam H - PLoS ONE (2016)

Bottom Line: Patients were then assessed clinically with sleep questionnaires, including the Pittsburgh Sleep Quality Index, and the Hoehn and Yahr scale.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).

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Seoul National University Boramae Hospital, Seoul, South Korea.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus

Oscillogram and spectrogram of nocturnal stridors.Two different types of waveforms in nocturnal stridor are described and the snoring signal of each patient was analyzed. Each sample has a duration of 40 ms. (A) Stridor in patient No. 3 presents a rhythmic sinusoidal waveform with a frequency of 250 Hz (left). The signal of snoring in patient No. 3 was irregular and non-periodic (right). (B) Oscillogram of patient No. 8 shows a semirhythmic signal (left). Analysis of snoring in patient No. 8 shows a chaotic signal (right). (C) Spectrogram of patient No. 2 shows three formants. The first (F1), second (F2), and third (F3) formants are indicated by black arrows.
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pone.0153935.g001: Oscillogram and spectrogram of nocturnal stridors.Two different types of waveforms in nocturnal stridor are described and the snoring signal of each patient was analyzed. Each sample has a duration of 40 ms. (A) Stridor in patient No. 3 presents a rhythmic sinusoidal waveform with a frequency of 250 Hz (left). The signal of snoring in patient No. 3 was irregular and non-periodic (right). (B) Oscillogram of patient No. 8 shows a semirhythmic signal (left). Analysis of snoring in patient No. 8 shows a chaotic signal (right). (C) Spectrogram of patient No. 2 shows three formants. The first (F1), second (F2), and third (F3) formants are indicated by black arrows.

Mentions: Nocturnal stridors were evaluated by analyzing the oscillogram and spectrogram. The mean fundamental frequency was 193.8 ± 51.9 Hz (male, 168.6 ± 42.9; female, 229.1 ± 42.2). The jitter was 9.4 ± 2.5% and the shimmer was 14.6 ± 4.3%. All stridors exhibited the formation of formants and harmonics, which were demonstrated in the spectrogram. According to Yanagihara’s classification, nine patients showed nocturnal stridor with rhythmic waveform (type I), and 13 displayed the semirhythmic waveform (type II). Snoring in 18 patients presented irregular shaped sound (type III) with no formants and harmonics (Fig 1). Individual sound analysis and each PSG data are included (S2 Table).


Acoustic Characteristics of Stridor in Multiple System Atrophy.

Koo DL, Lee JY, Joo EY, Hong SB, Nam H - PLoS ONE (2016)

Oscillogram and spectrogram of nocturnal stridors.Two different types of waveforms in nocturnal stridor are described and the snoring signal of each patient was analyzed. Each sample has a duration of 40 ms. (A) Stridor in patient No. 3 presents a rhythmic sinusoidal waveform with a frequency of 250 Hz (left). The signal of snoring in patient No. 3 was irregular and non-periodic (right). (B) Oscillogram of patient No. 8 shows a semirhythmic signal (left). Analysis of snoring in patient No. 8 shows a chaotic signal (right). (C) Spectrogram of patient No. 2 shows three formants. The first (F1), second (F2), and third (F3) formants are indicated by black arrows.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4836672&req=5

pone.0153935.g001: Oscillogram and spectrogram of nocturnal stridors.Two different types of waveforms in nocturnal stridor are described and the snoring signal of each patient was analyzed. Each sample has a duration of 40 ms. (A) Stridor in patient No. 3 presents a rhythmic sinusoidal waveform with a frequency of 250 Hz (left). The signal of snoring in patient No. 3 was irregular and non-periodic (right). (B) Oscillogram of patient No. 8 shows a semirhythmic signal (left). Analysis of snoring in patient No. 8 shows a chaotic signal (right). (C) Spectrogram of patient No. 2 shows three formants. The first (F1), second (F2), and third (F3) formants are indicated by black arrows.
Mentions: Nocturnal stridors were evaluated by analyzing the oscillogram and spectrogram. The mean fundamental frequency was 193.8 ± 51.9 Hz (male, 168.6 ± 42.9; female, 229.1 ± 42.2). The jitter was 9.4 ± 2.5% and the shimmer was 14.6 ± 4.3%. All stridors exhibited the formation of formants and harmonics, which were demonstrated in the spectrogram. According to Yanagihara’s classification, nine patients showed nocturnal stridor with rhythmic waveform (type I), and 13 displayed the semirhythmic waveform (type II). Snoring in 18 patients presented irregular shaped sound (type III) with no formants and harmonics (Fig 1). Individual sound analysis and each PSG data are included (S2 Table).

Bottom Line: Patients were then assessed clinically with sleep questionnaires, including the Pittsburgh Sleep Quality Index, and the Hoehn and Yahr scale.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).

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Seoul National University Boramae Hospital, Seoul, South Korea.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus