No AccessAmerican Journal of Speech-Language PathologyReview Article1 Aug 2015

Evidence-Based Systematic Review: Effects of Speech-Language Pathology Treatment for Individuals With Paradoxical Vocal Fold Motion


    In this article, our goal was to determine the state of the evidence and the effect of speech-language pathology (SLP) treatment for individuals with paradoxical vocal fold motion (PVFM).


    The American Speech-Language-Hearing Association's National Center for Evidence-Based Practice in Communication Disorders searched 22 electronic databases using key words related to PVFM, speech or voice treatment, and behavioral intervention for articles published through July 2013. Identified articles were systematically evaluated to assess the quality of the evidence using a modification of the American Speech-Language-Hearing Association's critical appraisal scheme.


    Sixty-five articles met the search criteria. Only 2 out of the 65 articles were judged to contain adequate evidence to evaluate the effect of SLP treatment for PVFM. All 65 articles exemplify the state of the evidence for SLP treatment for PVFM.


    The state of the evidence for the use of SLP treatment is in its infancy, with a majority of articles in the exploratory stage of research. Consequently, few clinical implications can be drawn at this time. SLP treatment for PVFM is promising; however, there is clearly a pressing need for systematic experimental studies that involve a control group to further the evidence base.

    Supplemental Material

    References marked with an asterisk indicate studies included in the evidence-based systematic review (but not necessarily cited in the text).


    • *Altman, K. W., Mirza, N., Ruiz, C., & Sataloff, R. T. (2000). Paradoxical vocal fold motion: Presentation and treatment options.Journal of Voice, 14, 99–103.
    • American Psychiatric Association. (1987). Diagnostic and statistical manual of mental disorders (3rd ed., rev.). Washington, DC: Author.
    • Anbar, R. D., & Hehir, D. A. (2002). Hypnosis as a diagnostic modality for vocal cord dysfunction.Pediatrics, 106, e81. doi:10.1542/peds.106.6.e81
    • Andrianopoulos, M. V., Gallivan, G. J., & Gallivan, H. (2000). PVCM, PVCD, EPL, and irritable larynx syndrome: What are we talking about and how do we treat it?.Journal of Voice, 14, 607–618.
    • Appelblatt, N. H., & Baker, S. R. (1981). Functional upper airway obstruction.Archives of Otolaryngology, 107, 305–306.
    • *Archer, G. J., Hoyle, J. L., McCluskey, A., & Macdonald, J. (2000). Inspiratory vocal cord dysfunction, a new approach in treatment.European Respiratory Journal, 15, 617–618.
    • *Bahrainwala, A. H., Simon, M. R., Harrison, D. D., Toder, D., & Secord, E. A. (2001). Atypical expiratory flow volume curve in an asthmatic patient with vocal cord dysfunction.Annals of Allergy, Asthma & Immunology, 86, 439–443.
    • *Barnes, S. D., Grob, C. S., Lachman, B. S., Marsh, B. R., & Loughlin, G. M. (1986). Psychogenic upper airway obstruction presenting as refractory wheezing.Journal of Pediatrics, 109, 1067–1070.
    • *Bittleman, D. B., Smith, R. J. H., & Weiler, J. M. (1994). Abnormal movement of the arytenoid region during exercise presenting as exercise-induced asthma in an adolescent athlete.Chest, 106, 615–616.
    • Blager, F. B., Gay, M. L., & Wood, R. P. (1988). Voice therapy techniques adapted to treatment of habit cough: A pilot study.Journal of Communication Disorders, 21, 393–100.
    • Blake, M. L., Frymark, T., & Venediktov, R. (2013). An evidence-based systematic review on communication treatments for individuals with right hemisphere brain damage.American Journal of Speech-Language Pathology, 22, 146–160.
    • Borg, G. M. (1970). Perceived exertion as an indicator of somatic stress.Scandinavian Journal of Rehabilitation Medicine, 2(2), 92–98.
    • Brown, T. M., Merritt, W. D., & Evans, D. L. (1988). Psychogenic vocal cord dysfunction masquerading as asthma.The Journal of Nervous and Mental Disease, 176, 308–310.
    • Brugman, S. M. (2003). The many faces of vocal cord dysfunction: What 36 years of literature tell us.American Journal of Respiratory and Critical Care Medicine, 167, A588.
    • Bucca, C., Rolla, G., Brussino, L., De Rose, V., & Bugiani, M. (1995). Are asthma-like symptoms due to bronchial or extrathoracic airway dysfunction?.The Lancet, 346, 791–795.
    • *Campainha, S., Ribeiro, C., Guimarães, M., & Lima, R. (2012). Vocal cord dysfunction: A frequently forgotten entity.Case Reports in Pulmonology, 2012, 525493. doi:10.1155/2012/525493
    • Campbell, A. H., Mestitz, H., & Pierce, R. (1990). Brief upper airway (laryngeal) dysfunction.Australian and New Zealand Journal of Medicine, 20, 663–668.
    • *Chawla, S. S., Upadhyay, B. K., & MacDonnell, K. F. (1984). Laryngeal spasm mimicking bronchial asthma.Annals of Allergy, 53, 319–321.
    • Cherney, L. R., Patterson, J. P., Raymer, A., Frymark, T., & Schooling, T. (2008). Evidence-based systematic review: Effects of intensity of treatment and constraint-induced language therapy for individuals with stroke-induced aphasia.Journal of Speech, Language, and Hearing Research, 51, 1282–1299. doi:10.1044/1092-4388(2008/07-0206)
    • *Chiang, T., Marcinow, A. M., deSilva, B. W., Ence, B. N., Lindsey, S. E., & Forrest, L. A. (2013). Exercise-induced paradoxical vocal fold motion disorder: Diagnosis and management.Laryngoscope, 123, 727–731. doi:10.1002/lary.23654
    • *Chiang, W. C., Goh, A., Ho, L., Tang, J. P., & Chay, O. M. (2008). Paradoxical vocal cord dysfunction: When a wheeze is not asthma.Singapore Medical Journal, 49(4), e110–e112.
    • *Christopher, K. L., Wood, R. P., II, Eckert, R. C., Blager, F. B., Raney, R. A., & Souhrada, J. F. (1983). Vocal-cord dysfunction presenting as asthma.New England Journal of Medicine, 308, 1566–1570.
    • Ciccolella, D. E., Brennan, K. J., Borbely, B., & Criner, G. J. (1997). Identification of vocal cord dysfunction (VCD) and other diagnoses in patients admitted to an inner city university hospital asthma center.American Journal of Respiratory Critical Care Medicine, 155, A82.
    • Collett, P. W., Brancatisano, T., & Engel, L. A. (1983). Spasmodic croup in the adult.The American Review of Respiratory Disease, 127, 500–504.
    • *Corren, J., & Newman, K. B. (1992). Vocal cord dysfunction mimicking bronchial asthma.Postgraduate Medicine, 92(6), 153–156.
    • *Craig, T., Sitz, K., Squire, E., Smith, L., & Carpenter, G. (1992). Vocal cord dysfunction during wartime.Military Medicine, 157, 614–616.
    • Denoyelle, F., Garabedian, E. N., Roger, G., & Tashjian, G. (1996). Laryngeal dyskinesia as a cause of stridor in infants.Archives of Head and Neck Surgery, 122, 612–616.
    • *Doshi, D. R., & Weinberger, M. M. (2006). Long-term outcome of vocal cord dysfunction.Annals of Allergy, Asthma & Immunology, 96, 794–799.
    • *Earles, J., Kerr, B., & Kellar, M. (2003). Psychophysiologic treatment of vocal cord dysfunction.Annals of Allergy, Asthma & Immunology, 90, 669–671.
    • *Echternach, M., Delb, W., Verse, T., & Richter, B. (2008). Does isolated expiratory vocal cord dysfunction exist?.Otolaryngology—Head and Neck Surgery, 138, 805–806.
    • Freedman, M. R., Rosenberg, S. J., & Schmaling, K. B. (1991). Childhood sexual abuse in patients with paradoxical vocal cord dysfunction.The Journal of Nervous and Mental Disease, 179, 295–298.
    • Geist, R., & Tallett, S. E. (1990). Diagnosis and management of psychogenic stridor caused by a conversion disorder.Pediatrics, 86, 315–317.
    • *Harbison, J., Dodd, J., & McNicholas, W. T. (2000). Paradoxical vocal cord motion causing stridor after thyroidectomy.Thorax, 55, 533–534.
    • *Hatzelis, V., & Murry, T. (2012). Paradoxical vocal fold motion: Respiratory retraining to manage long-term symptoms.Jornal da Sociedade Brasileira de Fonoaudiologia, 24(1), 80–85.
    • *Hayes, J. P., Nolan, M. T., Brennan, N., & FitzGerald, M. X. (1993). Three cases of paradoxical vocal cord adduction followed up over a 10-year period.Chest, 104, 678–680.
    • Heiser, J. M., Kahn, M. L., & Schmidt, T. A. (1990). Functional airway obstruction presenting as stridor: A case.The Journal of Emergency Medicine, 8, 285–289.
    • Jain, S., Bandi, V., Officer, T., Zimmerman, J., Hanania, N., & Guntupalli, K. (1999). Incidence of vocal cord dysfunction in patients presenting to emergency room with acute asthma exacerbation.Chest, 116(Suppl. 2), 243S.
    • *Kayani, S., & Shannon, D. C. (1998). Vocal cord dysfunction associated with exercise in adolescent girls.Chest, 113, 540–542.
    • Kellman, R. M., & Leopold, D. A. (1982). Paradoxical vocal cord motion: An important cause of stridor.The Laryngoscope, 92, 58–60.
    • Kenn, K., & Schmitz, M. (1997). Prevalence of vocal cord dysfunction in patients with dyspnea: First prospective clinical study.American Journal of Respiratory and Critical Care Medicine, 155, A965.
    • Kissoon, N., Kronick, J. B., & Frewen, T. C. (1988). Psychogenic upper airway obstruction.Pediatrics, 81, 714–717.
    • *Kivity, S., Bibi, H., Schwarz, Y., Greif, Y., Topilsky, M., & Tabachnick, E. (1986). Variable vocal cord dysfunction presenting as wheezing and exercise-induced asthma.Journal of Asthma, 23, 241–244.
    • *Koester, M. C., & Amundson, C. L. (2002). Seeing the forest through the wheeze: A case-study approach to diagnosing paradoxical vocal-cord dysfunction.Journal of Athletic Training, 37, 320–324.
    • Koufman, J. A., & Block, C. (2008). Differential diagnosis of paradoxical vocal fold movement.American Journal of Speech-Language Pathology, 17, 327–334.
    • Kuppersmith, R., Rosen, D. S., & Wiatrak, B. J. (1993). Functional stridor in adolescents.Journal of Adolescent Health, 14, 166–171.
    • Lacy, T. J., & McManis, S. E. (1994). Psychogenic stridor.General Hospital Psychiatry, 16, 213–223.
    • Landwehr, L. P., Wood, R. P., Blager, F. B., & Milgrom, H. (1996). Vocal cord dysfunction mimicking exercise-induced bronchospasm in adolescents.Pediatrics, 98, 971–974.
    • Lawrence, S. G. (2007). Laryngeal dyskinesia: An under-recognized condition.Emergency Medicine Australia, 19, 96–104.
    • *Leo, R. J., & Konakanchi, R. (1999). Psychogenic respiratory distress: A case of paradoxical vocal cord dysfunction and literature review.Primary Care Companion to the Journal of Clinical Psychiatry, 1(2), 39–46.
    • Loughlin, C. J., & Koufman, J. A. (1996). Paroxysmal laryngospasm secondary to gastroesophageal reflux.The Laryngoscope, 106, 1502–1505.
    • *Marsh, C. B., Trudeau, M. D., & Weiland, J. E. (1994). Recurrent asthma despite corticosteroid therapy in a 35-year-old woman.Chest, 105, 1855–1857.
    • Martin, R. J., Blager, F. B., Gay, M. L., & Wood, R. P. (1987). Paradoxic vocal cord motion in presumed asthmatics.Seminars in Respiratory Medicine, 8, 332–337.
    • *Maschka, D. A., Bauman, N. M., McCray, P. B., Hoffman, H. T., Karnell, M. P., & Smith, R. J. H. (1997). A classification scheme for paradoxical vocal cord motion.Laryngoscope, 107, 1429–1435.
    • *Mathers-Schmidt, B. A. (2001). Paradoxical vocal fold motion: A tutorial on a complex disorder and the speech-language pathologist's role.American Journal of Speech-Language Pathology, 10, 111–125. doi:10.1044/1058-0360(2001/012)
    • *Mathers-Schmidt, B. A., & Brilla, L. R. (2005). Inspiratory muscle training in exercise-induced paradoxical vocal fold motion.Journal of Voice, 19, 635–644.
    • Mathew, C. P., & Remmers, J. (1984). Respiratory function of the upper airway.In N. A. Saunders, C. E. Sullivan (Eds.), Sleep and breathing (pp. 163–200). New York, NY: Marcel Dekker.
    • *Maturo, S., Hill, C., Bunting, G., Baliff, C., Ramakrishna, J., Scirica, C., … Hartnick, C. (2011). Pediatric paradoxical vocal-fold motion: Presentation and natural history.Pediatrics, 128, e1443–e1449.
    • McFadden, E. R., & Zawadski, D. K. (1996). Vocal cord dysfunction masquerading as exercise-induced asthma: A physiologic cause for “choking” during athletic activities.American Journal of Respiratory and Critical Care Medicine, 153, 942–947.
    • Michelsen, L. G., & Vanderspek, F. L. (1988). An unexpected functional cause of upper airway obstruction.Anaesthesia, 43, 1028–1030.
    • *Mobeireek, A., Alhamad, A., Al-Subaei, A., & Alzeer, A. (1995). Psychogenic vocal cord dysfunction simulating bronchial asthma.European Respiratory Journal, 8, 1978–1981.
    • Morris, M. J., Allan, P. F., & Perkins, P. J. (2006). Vocal cord dysfunction.Obstructive Airways Disease, 13, 73–86.
    • Morris, M. J., Deal, L. E., Bean, D. R., Grbach, V. X., & Morgan, J. A. (1999). Vocal cord dysfunction in patients with exertional dyspnea.Chest, 116, 1676–1682.
    • Morrison, M., Rammage, L., & Emami, A. J. (1999). The irritable larynx syndrome.Journal of Voice, 13, 447–455.
    • *Mullinax, M. C., & Kuhn, W. F. (1996). Benign paradoxical vocal cord adduction presenting as acute stridor.European Journal of Emergency Medicine, 3(2), 102–105.
    • *Murry, T. (1998). Chronic cough: In search of the etiology.Seminars in Speech and Language, 19(1), 83–90.
    • *Murry, T., Branski, R. C., Yu, K., Cukier-Blaj, S., Duflo, S., & Aviv, J. E. (2010). Laryngeal sensory deficits in patients with chronic cough and paradoxical vocal fold movement disorder.Laryngoscope, 120, 1576–1581.
    • *Murry, T., Tabaee, A., & Aviv, J. E. (2004). Respiratory retraining of refractory cough and laryngopharyngeal reflux in patients with paradoxical vocal fold movement disorder.Laryngoscope, 114, 1341–1345.
    • *Murry, T., Tabaee, A., Owczarzak, V., & Aviv, J. E. (2006). Respiratory retraining therapy and management of laryngopharyngeal reflux in the treatment of patients with cough and paradoxical vocal fold movement disorder.Annals of Otology, Rhinology & Laryngology, 115, 754–758.
    • *Nacci, A., Fattori, B., Segnini, G., Dallan, I., Panicucci, E., Rocchi, V., & Ursino, F. (2011). Respiratory retraining therapy in long-term treatment of paradoxical vocal fold dysfunction.Folia Phoniatrica et Logopaedica, 63(3), 134–141.
    • *Nacci, A., Fattori, B., Ursino, F., Rocchi, V., Matteucci, F., Citi, C., … Dallan, I. (2007). Paradoxical vocal cord dysfunction: Clinical experience and personal considerations.Acta Otorhinolaryngologica Italica, 27(5), 248–254.
    • Newman, K. B., Mason, U. G., & Schmaling, K. B. (1995). Clinical features of vocal cord dysfunction.American Journal of Respiratory and Critical Care Medicine, 152, 1382–1386.
    • *Niven, R. M., Roberts, T., Pickering, C. A., & Webb, A. K. (1992). Functional upper airways obstruction presenting as asthma.Respiratory Medicine, 86, 513–516.
    • O'Connell, M. A., Sklarew, P. R., & Goodman, D. L. (1995). Spectrum of presentation of paradoxical vocal cord motion in ambulatory patients.Annals of Allergy, Asthma & Immunology, 74, 341–344.
    • Ophir, K., Katz, Y., Tavori, I., & Aladjem, M. (1990). Functional upper airway obstruction in adolescents.Archives of Otolaryngology—Head & Neck Surgery, 116, 1208–1209.
    • Patterson, R., Schatz, M., & Horton, M. (1974). Munchausen's stridor: Non-organic laryngeal obstruction.Clinical Allergy, 4, 307–310.
    • Perkner, J. J., Fennelly, K. P., Balkissoon, R., Bartelson, B. B., Ruttenber, A., Wood, R. P., & Newman, L. S. (1998). Irritant-associated vocal cord dysfunction.Journal of Occupational and Environmental Medicine, 40, 136–143.
    • Pierce, R. J., & Worsnop, C. J. (1999). Upper airway function and dysfunction in respiration.Clinical and Experimental Pharmacology and Physiology, 26, 1–10.
    • *Pinho, S. M. R., Tsuji, D. H., Sennes, L., & Menezes, M. (1997). Paradoxical vocal fold movement: A case report.Journal of Voice, 11, 368–372.
    • Pitchenik, A. F. (1991). Functional laryngeal obstruction relieved by panting.Chest, 100, 1465–1467.
    • Place, R., Morrison, A., & Arce, E. (2000). Vocal cord dysfunction.Journal of Adolescent Health, 27, 125–129.
    • Powell, D. M., Karanfilov, B. I., Beechler, K. B., Treole, K., Trudeau, M. D., & Forrest, A. (2000). Paradoxical vocal cord dysfunction in juveniles.Archives of Otolaryngology—Head & Neck Surgery, 126, 29–34.
    • *Powell, S. A., Nguyen, C. T., Gaziano, J., Lewis, V., Lockey, R. F., & Padhya, T. A. (2007). Mass psychogenic illness presenting as acute stridor in an adolescent female cohort.Annals of Otology, Rhinology & Laryngology, 116, 525–531.
    • *Rameau, A., Foltz, R. S., Wagner, K., & Zur, K. B. (2012). Multidisciplinary approach to vocal cord dysfunction diagnosis and treatment in one session: A single institutional outcome study.International Journal of Pediatric Otorhinolaryngology, 76(1), 31–35.
    • Ramírez, R. J., León, I., & Rivera, L. M. (1986). Episodic laryngeal dyskinesia: Clinical and psychiatric characterization.Chest, 90, 716–721.
    • *Reisner, C., & Nelson, H. S. (1997). Vocal cord dysfunction with nocturnal awakening.Journal of Allergy and Clinical Immunology, 99, 843–846.
    • *Renz, V., Hern, J., Tostevin, P., Hung, T., & Wyatt, M. (2000). Functional laryngeal dyskinesia: An important cause of stridor.Journal of Laryngology and Otology, 114, 790–792.
    • *Rhodes, R. K. (2008). Diagnosing vocal cord dysfunction in young athletes.Journal of the American Academy of Nurse Practitioners, 20, 608–613.
    • Rodenstein, D. O., Francis, C., & Stǎnescu, D. C. (1983). Emotional laryngeal wheezing: A new syndrome.The American Review of Respiratory Disease, 127, 354–356.
    • Rogers, J. H. (1980). Functional inspiratory stridor in children.The Journal of Laryngology and Otology, 94, 669–670.
    • *Rogers, J. H., & Stell, P. M. (1978). Paradoxical movement of the vocal cords as a cause of stridor.Journal of Laryngology and Otology, 92, 157–158.
    • *Ruddy, B. H., Davenport, P., Baylor, J., Lehman, J., Baker, S., & Sapienza, C. (2004). Inspiratory muscle strength training with behavioral therapy in a case of a rower with presumed exercise-induced paradoxical vocal-fold dysfunction.International Journal of Pediatric Otorhinolaryngology, 68, 1327–1332.
    • Rundell, K. W., & Spiering, B. A. (2003). Inspiratory stridor in elite athletes.Chest, 123, 468–474.
    • *Rusakow, L. S., Blager, F. B., Barkin, R. C., & White, C. W. (1991). Acute respiratory distress due to vocal cord dysfunction in cystic fibrosis.Journal of Asthma, 28, 443–446.
    • *Ryan, N. M., Vertigan, A. E., & Gibson, P. G. (2009). Chronic cough and laryngeal dysfunction improve with specific treatment of cough and paradoxical vocal fold movement.Cough, 5, 4. doi:10.1186/1745-9974-5-4
    • Sackett, D. L., Rosenberg, W. M. C., Gray, J. A. M., Haynes, R. B., & Richardson, W. S. (1996). Evidence-based medicine: What it is and what it isn't.British Medical Journal, 312, 71–72.
    • *Sandage, M. J., & Zelazny, S. K. (2004). Paradoxical vocal fold motion in children and adolescents.Language, Speech, and Hearing Services in Schools, 35, 353–362.
    • Sanford, C. A., Schooling, T., & Frymark, T. (2012). Determining the presence or absence of middle ear disorders: An evidence-based systematic review on the diagnostic accuracy of selected assessment instruments.American Journal of Audiology, 21, 251–268.
    • Sant'Ambrogio, G., & Sant'Ambrogio, F. B. (1996). Role of laryngeal afferents in cough.Pulmonary Pharmacology, 9, 309–314.
    • Sapienza, C. M. (2008). Respiratory muscle strength training.Current Opinion in Otolaryngology and Head and Neck Surgery, 16, 216–220.
    • Schlosser, R. W., Lee, D. L., & Wendt, O. (2008). Application of the percentage of non-overlapping data (PND) in systematic reviews and meta-analyses: A systematic review of reporting characteristics.Evidence-Based Communication Assessment and Intervention, 2(3), 163–187.
    • *Sette, L., Pajno-Ferrara, F., Mocella, S., Portuese, A., & Boner, A. L. (1993). Vocal cord dysfunction in an asthmatic child: Case report.Journal of Asthma, 30, 407–412.
    • *Shao, W., Chung, T., Berdon, W. E., Mellins, R. B., Griscom, N. T., Ruzal-Shapiro, C., & Schneider, P. (1995). Fluoroscopic diagnosis of laryngeal asthma (paradoxical vocal cord motion).American Journal of Roentgenology, 165, 1229–1231.
    • *Sharma, S., & Singh, B. K. H. (2007). Speech rehabilitation of paradoxical vocal fold movement.Malaysian Journal of Health Science, 5(1), 67–78.
    • Sim, T. C., McClean, S. P., Lee, J. L., Naranjo, M. S., & Grant, J. A. (1990). Functional laryngeal obstruction: A somatization disorder.The American Journal of Medicine, 88, 293–295.
    • *Skinner, D. W., & Bradley, P. J. (1989). Psychogenic stridor.Journal of Laryngology & Otology, 103, 383–385. doi:10.1017/S0022215100109028
    • *Smith, M. E., Darby, K. P., Kirchner, K., & Blager, F. B. (1993). Simultaneous functional laryngeal stridor and functional aphonia in an adolescent.American Journal of Otolaryngology, 14, 366–369.
    • Sukhani, R., Barclay, J., & Chow, J. (1993). Paradoxical vocal cord motion: An unusual cause of stridor in the recovery room.Anesthesiology, 79, 177–180.
    • *Sullivan, M. D., Heywood, B. M., & Beukelman, D. R. (2001). A treatment for vocal cord dysfunction in female athletes: An outcome study.Laryngoscope, 111, 1751–1755.
    • *Suri, J. C., Sen, M. K., Chakrabarti, S., & Mehta, C. (2002). Vocal cord dysfunction presenting as refractory asthma.Indian Journal of Chest Diseases & Allied Sciences, 44(1), 49–52.
    • *Suttithawil, W., Chakkaphak, S., Jaruchinda, P., & Fuangtong, R. (2006). Vocal cord dysfunction concurrent with a nutcracker esophagus and the role of gastroesophageal reflux disease.Annals of Allergy, Asthma & Immunology, 96, 373–375.
    • *Tajchman, U. W., & Gitterman, B. (1996). Vocal cord dysfunction associated with sexual abuse.Clinical Pediatrics, 35(2), 105–108.
    • *Tan, K. L., Eng, P., & Ong, Y. Y. (1997). Vocal cord dysfunction: Two case reports.Annals of the Academy of Medicine, Singapore, 26, 494–496.
    • Tate, R. L., McDonald, S., Perdices, M., Togher, L., Schultz, R., & Savage, S. (2008). Rating the methodological quality of single-subject designs and n-of-1 trials: Introducing the Single-Case Experimental Design (SCED) Scale.Neuropsychological Rehabilitation, 18, 385–401.
    • *Tilles, S. A. (2010). Exercise-induced respiratory symptoms: An epidemic among adolescents.Annals of Allergy, Asthma & Immunology, 104, 361–370.
    • Tousignant, G., & Kleiman, S. J. (1992). Functional stridor diagnosed by the anaesthetist.Canadian Journal of Anesthesia, 39, 286–289.
    • *Towey, M. P. (2012). Speech therapy telepractice for vocal cord dysfunction (VCD): MaineCare (Medicaid) cost savings.International Journal of Telerehabilitation, 4(1), 33–36.
    • Vertigan, A. E., Theodoros, D. G., Gibson, P. G., & Winkworth, A. L. (2006). The relationship between chronic cough and paradoxical vocal fold movement: A review of the literature.Journal of Voice, 20, 466–480.
    • *Vertigan, A. E., Theodoros, D. G., Winkworth, A. L., & Gibson, P. G. (2008). A comparison of two approaches to the treatment of chronic cough: Perceptual, acoustic, and electroglottographic outcomes.Journal of Voice, 22, 581–589.
    • Vlahakis, N. E., Patel, A. M., Maragos, N. E., & Beck, K. C. (2002). Diagnosis of vocal cord dysfunction: The utility of spirometry and plethysmography.Chest, 122, 2246–2249.
    • *Von Berg, S., Watterson, T., & Fudge, L. (1999). Behavioural management of paradoxical vocal fold movement.Phonoscope, 2, 145–147.
    • *Walaschek, C., Forster, J., & Echternach, M. (2010). Vocal cord dysfunction without end?.Klinische Pädiatrie, 222(2), 84–85.
    • *Warnes, E., & Allen, K. D. (2005). Biofeedback treatment of paradoxical vocal fold motion and respiratory distress in an adolescent girl.Journal of Applied Behavior Analysis, 38, 529–532.
    • *Weir, M. (2002). Vocal cord dysfunction mimics asthma and may respond to heliox.Clinical Pediatrics, 41(1), 37–41.
    • *Wilson, J. J., Theis, S. M., & Wilson, E. M. (2009). Evaluation and management of vocal cord dysfunction in the athlete.Current Sports Medicine Reports, 8(2), 65–70.

    Additional Resources