Here comes the pitch: Effortful pitch glide in treatment of dysphagia

Introduction

Hitting the high note during the falsetto exercise has been widely practiced by Speech Pathologists for many years. It was introduced by Dr.Jeri Logemann (1997) and described as an exercise for laryngeal elevation because of its presumed effect of lifting the larynx comparable to the swallow (p. 210) [1]. The exercise consists of gliding up in pitch to reach a high, squeaky voice, then holding it for several seconds with effort. Currently no studies exist investigating the effects of the falsetto on improving laryngeal elevation though there are numerous studies in the voice literature regarding pitch tasks and laryngeal kinematics.

What happens with laryngeal kinematics during pitch elevation?

Laryngeal kinematics have been evaluated during pitch elevation tasks using dynamic MRI. Laryngeal elevation was demonstrated with a high pitch task during production of /a/ [2]. In another study, an ascending humming task was shown to elicit laryngeal elevation, approximation of the larynx to hyoid and anterior and superior excursion of the hyoid [3]. These studies suggest pitch elevation tasks may facilitate laryngeal elevation.

What is the relationship between pitch elevation and aspiration?

Recently, pitch elevation and its relationship between components of the swallow were studied in dysphagic patients by Dr. Maladraki et al (2011) [4]. The authors hypothesized patients with decreased vocal range and/or maximum fundamental frequency would predict worse penetration-aspiration and/or residue scores. Pitch elevation of the patients was assessed by acoustical and perceptual measurements (fundamental frequency and normal/abnormal rating, respectively) in which they were instructed to produce /ah/ gliding their voice up as high as possible. The Penetration-Aspiration [5] and Residue Scale Scores [6] were used during videoflouroscopy to objectively assess the swallow. The results of the study showed patients with more severe penetration-aspiration scores for thin liquids demonstrated abnormal, or reduced, pitch and lower maximum fundamental frequency. Furthermore lower maximum fundamental frequency was shown to be associated with significantly higher mean residue scores. This study illustrates the relationship between vocal range and protection of the airway.

Pharyngeal squeeze maneuver

Another type of pitch task utilized is the pharyngeal squeeze maneuver (PSM) to assess and improve pharyngeal strength. It was originally developed by Bastian (1993) to assess pharyngeal constrictors during fiberoptic endoscopic evaluation of swallowing (FEES) [7]. The PSM is performed by generating a forceful and effortful “ee” sound to stimulate contraction of the pharyngeal constrictors in which strength of the musculature can be estimated.

The genesis of the effortful pitch glide

The PSM in conjunction with pitch elevation had been coupled to develop a potential new exercise known as the effortful pitch glide (EPG). My co-authors and I developed the EPG in attempts to target both laryngeal and pharyngeal muscles [8]. The EPG consisted of producing the /i/ sound at modal pitch, steadily increasing to the highest pitch and once reached, applying effort to generate a forceful “ee” sound.

In a study by Pearson et al., (2013), muscle function MRI was used to evaluate activation of muscle contraction with the EPG in which the suprahyoids and longitudinal pharyngeal muscles exhibited significantly greater muscle activation compared to the swallow [9]. For our study, we hypothesized the biomechanics of the EPG would stimulate significantly greater excursions compared to the biomechanics of the swallow in the areas of anterior hyoid, superior hyoid, laryngeal elevation, hyolaryngeal approximation, lateral pharyngeal wall medialization and pharyngeal shortening.

Methods and results of the effortful pitch glide

Our study included first teaching the EPG via laryngoscopy then assessment of the biomechanics of the EPG and the swallow with dynamic MRI in 11 healthy subjects (mean age = 25 years). Analysis of the biomechanics did not demonstrate greater excursion of the EPG than swallowing. Interestingly, 5 of the 6 excursions exhibited no statistically significant difference between the EPG and the swallow. These results indicated the measured biomechanics of the EPG were comparable to swallow regarding anterior hyoid, laryngeal elevation, hyolaryngeal excursion and lateral pharyngeal medialization.

Clinical implications of the EPG and pitch elevation tasks

The results from our study suggested the biomechanics of the EPG were similar to the biomechanics of deglutition. Multiple muscle functions pertinent to the swallow were shown to be elicited by the EPG consisting of laryngeal elevation, anterior hyoid and the longitudinal pharyngeal muscles, which are responsible for lifting the larynx and shortening the pharynx. There are some caveats to the use of the EPG as a potential exercise for these muscle functions. First, the possibility of vocal hyperfunction is a concern due to the effortful phonation produced with the EPG. Secondly, the effects of the EPG as an exercise are unknown as our study was conduced on healthy subjects without dysphagia. Therefore future studies are needed to examine these factors.

As highlighted earlier, pitch elevation has been shown to be associated with prediction of penetration-aspiration with thin liquids and residue. The pitch elevation in conjunction with the pharyngeal squeeze maneuver demonstrated similar kinematics compared to the swallow. Therefore the utility of pitch elevation tasks may be useful during clinical swallow evaluations as an informal assessment of dysphagia and as possible therapeutic benefits.

References

1. Logemann, J. (1997). Evaluation and treament of swallowing disorders (2^nd ed.). Austin,TX: Pro-Ed.
2. Echternach, M., Traser, L., Markl, M., & Richter, B. (2011). Vocal tract configurations in male alto register functions. Journal of Voice : Official Journal of the Voice Foundation, 25(6), 670-677. doi:10.1016/j.jvoice.2010.09.008; 10.1016/j.jvoice.2010.09.008
3. Miller, N. A., Gregory, J. S., Semple, S. I., Aspden, R. M., Stollery, P. J., & Gilbert, F. J. (2012). The effects of humming and pitch on craniofacial and craniocervical morphology measured using MRI. Journal of Voice : Official Journal of the Voice Foundation, 26(1), 90-101. doi:10.1016/j.jvoice.2010.10.017; 10.1016/j.jvoice.2010.10.017
4. Malandraki, G. A., Hind, J. A., Gangnon, R., Logemann, J. A., & Robbins, J. (2011). The utility of pitch elevation in the evaluation of oropharyngeal dysphagia: Preliminary findings. American Journal of Speech-Language Pathology / American Speech-Language-Hearing Association, 20(4), 262-268. doi:10.1044/1058-0360(2011/10-0097); 10.1044/1058-0360(2011/10-0097)
5. Rosenbek, J.C., Robbins, J.A., Roecker, E.B., Coyle, J.L., & Wood J.L. (1996). A penetration-aspiration scale. Dysphagia,11(2), 93-8. doi:10.1007/BF00417897
6. Hind, J.A., Nicosia, M.A., Roecker, E.B., Carnes, M.L., & Robbins J. (2001).Comparison of effortful and noneffortful swallows in healthy middle-aged and older adults. Arch Phys Med Rehabil. 2001 Dec;82(12):1661-5.
7. Bastian, R. W. (1993). The videoendoscopic swallowing study: An alternative and partner to the videofluoroscopic swallowing study. Dysphagia, 8(4), 359-367.
8. Miloro, K.V., Langmore, S.E., & Pearson, W.G. Jr. (2014). Effortful Pitch Glide: A Potential New Exercise Evaluated by Dynamic MRI. J Speech Lang Hear Res. Feb 1. doi: 10.1044/2014_JSLHR-S-13-0168. [Epub ahead of print]
9. Pearson, W. G.,Jr, Hindson, D. F., Langmore, S. E., & Zumwalt, A. C. (2013). Evaluating swallowing muscles essential for hyolaryngeal elevation by using muscle functional magnetic resonance imaging. International Journal of Radiation Oncology, Biology, Physics, 85(3), 735-740. doi:10.1016/j.ijrobp.2012.07.2370; 10.1016/j.ijrobp.2012.07.2370