Extreme Sawtooth-Sign in Motor Neuron Disease (MND) suggests Laryngeal Resistance to Forced Expiratory Airflow

Abstract

Objective:

The impact of laryngeal dysfunction on airflow has not been well characterized in motor neuron disease (MND). This study aimed to detect and characterize extreme airflow oscillations informally observed during volitional cough and forced vital capacity (FVC) tasks in individuals with MND who demonstrated neurolaryngeal impairments including reduced speed and extent of vocal fold abduction compared to healthy controls during volitional cough expulsion. The extreme airflow oscillations in the MND group, when viewed as a flow-volume loop, appeared similar to the “sawtooth-sign.” If the airflow oscillations are periodic in a range similar to phonation, they may reflect reduced laryngeal patency.

Methods:

Volitional cough and FVC airflow data (3 trials each) from 12 participants with MND with bulbar/laryngeal involvement (3 F; ages 45-76) and 12 healthy controls (6 F; ages 41-68) were analyzed for periodicity. Percent and absolute durations of periodicity of the flow oscillations were calculated by an algorithm applied to the airflow signals. In addition, the frequency, magnitude, and kurtosis of the periodic airflow oscillations were described and compared between groups.

Results:

In both volitional cough and FVC trials, the percent of airflow periodicity during forced expiration was significantly higher (z = 3.54) in individuals with MND, adjusted for age and sex. Periodic airflow accounted for on average 28% of the total time in participants with MND and was within a frequency range similar to phonation. Magnitude of the airflow oscillations was also larger for participants with MND (z = 3.46), and kurtosis of airflow was smaller (z = −4.70) during forced expiration, indicating persistent airflow oscillations throughout exhalation.

Conclusions:

The significantly larger-magnitude, lower-kurtosis, and more prominent presence of sawtooth-like airflow periodicity within a frequency range similar to phonation observed in individuals with MND with neurolaryngeal impairments suggests glottic airflow resistance during forced expiration.

Keywords

motor neuron disease (MND)glottic resistance cough forced vital capacity (FVC)sawtooth-sign

Get full access to this article

View all access options for this article.

References

Lo Coco

Marchese

Pesco

La Bella

Piccoli

Lo Coco

. Noninvasive positive-pressure ventilation in ALS: predictors of tolerance and survival. Neurology. 2006;67(5):761-765.

Boitano

. Management of airway clearance in neuromuscular disease. Respir Care. 2006;51(8):913-924.

Andersen

Sandnes

Fondenes

, et al. Laryngeal responses to mechanically assisted cough in progressing amyotrophic lateral sclerosis. Respir Care. 2018;63(5):538-549.

Britton

Benditt

Merati

, et al. Associations between laryngeal and cough dysfunction in motor neuron disease with bulbar involvement. Dysphagia. 2014;29(6):637-646.

van der Graaff

Grolman

Westermann

, et al. Vocal cord dysfunction in amyotrophic lateral sclerosis: four cases and a review of the literature. Arch Neurol. 2009;66(11):1329-1333.

Sanders

Martin

Pennock

Rogers

. The detection of sleep apnea in the awake patient. The ‘saw-tooth’ sign. JAMA. 1981;245(23):2414-2418.

Vincken

Dollfuss

Cosio

. Upper airway dysfunction detected by respiratory flow oscillations. Eur J Respir Dis. 1986;68(1):50-57.

Hadjikoutis

Wiles

. Respiratory complications related to bulbar dysfunction in motor neuron disease. Acta Neurol Scand. 2001;103(4):207-213.

Vincken

Cosio

. Flow oscillations on the flow-volume loop: a nonspecific indicator of upper airway dysfunction. Bull Eur Physiopathol Respir. 1985;21(6):559-567.

10.

Vincken

Elleker

Cosio

. Detection of upper airway muscle involvement in neuromuscular disorders using the flow-volume loop. Chest. 1986;90(1):52-57.

11.

Vincken

Cosio

. Flow oscillations on the flow-volume loop: clinical and physiological implications. Eur Respir J. 1989;2(6):543-549.

12.

Vincken

Gauthier

Dollfuss

Hanson

Darauay

Cosio

. Involvement of upper-airway muscles in extrapyramidal disorders. A cause of airflow limitation. N Engl J Med. 1984;311(7):438-442.

13.

Forshew

Bromberg

. A survey of clinicians’ practice in the symptomatic treatment of ALS. Amyotroph Lateral Scler Other Motor Neuron Disord. 2003;4(4):258-263.

14.

Hillel

Miller

. Bulbar amyotrophic lateral sclerosis: patterns of progression and clinical management. Head Neck. 1989;11(1):51-59.

15.

Polkey

Lyall

Green

Nigel Leigh

Moxham

. Expiratory muscle function in amyotrophic lateral sclerosis. Am J Respir Crit Care Med. 1998;158(3):734-741.

16.

Rothenberg

. Measurement of airflow in speech. J Speech Hear Res. 1977;20(1):155-176.

17.

Hillel

. The study of laryngeal muscle activity in normal human subjects and in patients with laryngeal dystonia using multiple fine-wire electromyography. Laryngoscope. 2001;111(4 Pt 2 Suppl 97):1-47.

18.

Kuna

Vanoye

. Laryngeal response during forced vital capacity maneuvers in normal adult humans. Am J Respir Crit Care Med. 1994;150(3):729-734.

19.

McCool

. Global physiology and pathophysiology of cough. Chest. 2006;129(1 suppl):48S-53S.

20.

Raudenbush

Bryk

. Hierarchical Linear Models: Applications and Data Analysis Methods. 2nd ed. Sage Publications, Inc.; 2002.

21.

Hedges

. Distribution theory for glass’s estimator of effect size and related estimators. J Educ Stat. 1981;6(2):107-128.

22.

Britton

Benditt

Merati

, et al. Associations between laryngeal and cough dysfunction in motor neuron disease with bulbar involvement. Dysphagia. 2014;29(6):637-646.

23.

Murakami

Yagi

Mizuno

Nomura

. A histochemical study of the intrinsic laryngeal muscles in amyotrophic lateral sclerosis (ALS). Abst 6th World Congress Bronchoesophagol. 1990;5(3):171.

24.

Shembel

Hartnick

Bunting

, et al. The study of laryngoscopic and autonomic patterns in exercise-induced laryngeal obstruction. Ann Otol Rhinol Laryngol. 2018:127(11):754-762.

25.

Garrel

Amy de la Breteque

Ghio

Giovanni

Guerrier

. Importance of tussometry in unilateral laryngeal paralysis. Rev Laryngol Otol Rhinol (Bord). 2002;123(5):303-306.

26.

Murty

Kelly

Bradley

. Tussometry: an objective assessment of vocal cord function. Ann Otol Rhinol Laryngol. 1993;102(10):743-747.

27.

Murty

Kelly

Veale

. Tussometry and lung function. Clin Otolaryngol Allied Sci. 1994;19(2):117-119.

28.

Murty

Lancaster

Kelly

. Cough intensity in patients with a vocal cord palsy. Clin Otolaryngol Allied Sci. 1991;16(3):248-251.

29.

Chaudri

Liu

Hubbard

Jefferson

Kinnear

. Relationship between supramaximal flow during cough and mortality in motor neuron disease. Eur Respir J. 2002;19(3):434-438.

30.

Khosla

Murugappan

Gutmark

. What can vortices tell us about vocal fold vibration and voice production. Curr Opin Otolaryngol Head Neck Surg. 2008;16(3):183-187.

31.

Oren

Khosla

Murugappan

King

Gutmark

. Role of subglottal shape in turbulence reduction. Ann Otol Rhinol Laryngol. 2009;118(3):232-240.

32.

Holmberg

Hillman

Perkell

. Glottal airflow and transglottal air pressure measurements for male and female speakers in soft, normal, and loud voice. J Acoust Soc Am. 1988;84(2):511-529.

33.

Pedersen

Lyager

Ingram

Jr . Airway dynamics in transition between peak and maximal expiratory flow. J Appl Physiol (1985). 1985;59(6):1733-1746.

34.

Matsuda

Shimizu

Nakayama

Haraguchi

. Cough peak flow decline rate predicts survival in patients with amyotrophic lateral sclerosis. Muscle Nerve. 2019;59(2):168-173.

35.

Miller

Jackson

Kasarskis

, et al. Practice parameter update: The care of the patient with amyotrophic lateral sclerosis: drug, nutritional, and respiratory therapies (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. 2009;73(15):1218-1226.

36.

Hess

. Noninvasive Ventilation for Neuromuscular Disease. Clin Chest Med. 2018;39(2):437-447.

37.

Andrews

Meng

Kulke

, et al. Association between decline in slow vital capacity and respiratory insufficiency, use of assisted ventilation, tracheostomy, or death in patients with amyotrophic lateral sclerosis. JAMA Neurol. 2018;75(1):58-64.

Supplementary Material

Please find the following supplemental material available below.

For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.

For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.

0.00 MB

0.18 MB

0.12 MB

0.21 MB