Guiding Principles and Considerations for Swallowing Therapy in Head and Neck Cancers

Educational Objectives

The goal of this program is to improve use of swallowing therapy in management of head and neck cancers. After hearing and assimilating this program, the clinician will be better able to:

1. Compare flexible endoscopic evaluation of swallowing with fluoroscopy in detection of pharyngeal complications caused by head and neck cancers.
2. Optimize use of high-resolution pharyngeal manometry in patients with head and neck cancers.
3. Differentiate lower from upper motor neuron impairments associated with swallowing complications in patients with head and neck cancers.
4. Contrast the approach to facial asymmetry associated with hypokinetic movement disorder vs fibrosis in patients with head and neck cancers.
5. Use expiratory muscle strength training in patients with swallowing complications associated with head and neck cancers.

Summary

The International Classification of Functioning, Disability, and Health: a theoretical framework developed by the World Health Organization to create a biopsychosocial model where the patient is at the center of care; clinicians must understand how a patient’s diagnosis affects their activities of daily living

Shared decision-making: patients with head and neck malignancies may have impairments in, eg, cough, swallowing, and communication; provide basic education and counseling; consider using exercise-based interventions (proactive or reactive), while keeping in mind that patient adherence is influenced by barriers and facilitators; compensatory strategies include positional strategies and dietary modifications; surgical and pharmaceutical interventions are also available; clinicians are experts in their fields (ie, current trends in research and practice patterns), but patients are experts in their own body; speech pathologists and physicians treating patients with head and neck cancers should guide patients and involve them in the shared decision-making process

Evidence-based practice: the 3 pillars of evidence-based practice are 1) clinical experience, 2) patient values and abilities, and 3) external evidence (ie, the research); clinicians must apply therapies with strong scientific validity; however, evidence that is statistically significant may not always be true, clinically meaningful, or generalizable

“True”: a p-value <0.05 indicates only that the result is likely to be true; a false-positive result can happen by chance, through use of an incorrect statistical test, or through publication bias (ie, studies with less significant results are less likely to be published); reproducibility is a defining feature of science, but there is a reproducibility crisis; in a study of 100 experimental and correlational studies published in respected psychology journals, 97% of the original studies had statistically significant results but only 36% of the replications by the authors were found to be statistically significant

“Clinically meaningful”: consider effect sizes and the clinical impact of therapy on the patient; because the process of effective and safe swallowing is multifactorial, explore different therapy exercises; the effect size of each exercise may be small but should be clinically meaningful

“Generalizable”: randomized controlled trials have large patient populations with stringent inclusion and exclusion criteria that are different from actual patients that the physician is seeing; generalizing such results across patient populations is difficult; case studies and single-subject research designs are ranked lower on the research pyramid but may closely match an actual patient and give clinician ideas for management; because there are few studies of individual swallowing exercises for patients with head and neck cancer, clinicians typically use intellect and intuition to decide on therapeutic options (ie, theory-based practice)

Key points: clinicians working with patients who have head and neck cancer must incorporate evidence, patient values, clinical experience, and understanding of systems; theory-based practice relies on understanding how human systems work and developing therapeutic approaches that fit into these systems; eg, patients with muscle weakness should be advised to do strengthening exercises not stretching, and patients with stiffness should be advised to do stretching exercises to improve flexibility not strengthening exercises, and patients with discoordination should be advised to do motor-learning exercises

Framework for evaluation: pathogenesis — some common underlying causes of impairments in cough and swallowing are altered anatomy, diminished peripheral sensation, and changes in somatosensory processing, motor control and coordination, cranial motor nerve function, tissue pliability, or muscle strength; pathophysiology — characterizes the physiologic impairment, eg, incomplete closure of the laryngeal vestibule (visible on fluoroscopy); the physiology of swallowing is evaluated using kinematics and pressures; kinematics refers to movement of structures without consideration of the forces behind them; spatial kinematics represent where structures are located in space and how far they may be moved (eg, complete vs incomplete closure of the laryngeal vestibule); temporal kinematics describes, eg, the timing and duration of closure of laryngeal vestibule; swallowing pressures are not routinely evaluated unless manometry is performed; swallowing pressures can be characterized by timing and extent (ie, magnitude); “kinetics” refers to kinematics plus pressures

Functional impairment: the consequence of the physiologic impairment; impaired swallowing may lead to pharyngeal residue, nasal regurgitation, penetration, aspiration, reduced cough and peak expiratory flow rate (the amount of air exhaled in the cough is reduced); symptoms of dysphagia — may or may not be present and may or may not correspond with functional impairments; they include coughing when eating and drinking, sensation of things sticking, or sensation of pain, effort, and fatigue

Cascade: chemotherapy or radiation therapy can cause fibrosis or blunted sensation; this may or may not lead to a physiologic impairment (eg, reduced spatial kinematics or range of motion displacement), which may or may not lead to the functional impairment of pharyngeal residue, which may or may not lead to the symptom of feeling that something is stuck in the throat

Instrumental assessments: identify the pathophysiology and the functional impairments; the main tools are fiberoptic endoscopic evaluation of swallowing (FEES), fluoroscopy, and high-resolution manometry

Endoscopic assessments: critical for understanding functional swallowing impairments, especially as they relate to the pharyngeal phase of swallowing; a systematic review (Checklin [2022]) demonstrated that FEES is as sensitive as fluoroscopy (and possibly more sensitive) at detecting the presence and severity of pharyngeal residue, penetration, and aspiration; however, it does not visualize the esophageal phase (the clinician can make only inferences); FEES does not provide much information about swallowing kinematics and pressures

Video fluoroscopy: gives information about all phases of swallowing; it demonstrates residue left in the oral cavity, penetration or aspiration during the pharyngeal phase, and regurgitation; esophageal follow-through shows bolus clearance; it may not as be good as FEES for the pharyngeal phase of swallowing, but it is excellent for assessing kinematics; it does not provide information about medial movements of laryngeal structures or swallowing pressures

High-resolution pharyngeal manometry: does not provide much information about functional impairments; impedance testing gives some insight into swallowing pressures but not about kinematics; it is the only instrumental tool available to determine whether a patient has a strong swallow

Clinical swallowing evaluation (CSE): helps clinicians make an educated hypothesis about the pathogenesis, which guides therapy; the cause of dysphagia or dystussia (cough impairment) may be due to an impairment of peripheral sensations, somatosensory processing, motor control and coordination, muscle strength, tissue pliability, or topography of the upper airway; the CSE is performed in the context of knowing the relevant medical and surgical history, what that means from a recovery standpoint (theory based), and other tasks performed during assessment; eg, spastic dysarthria may indicate upper motor neuron impairment that contributes to cough and swallowing dysfunction; flaccid dysarthria may indicate a lower motor neuron impairment causing cough and swallowing impairment; ataxia, hyperkinesia, or hypokinesia provide clues to both speech and swallowing (shared musculature); oral mechanical examination and cough testing should be performed as well

Facial asymmetry: may be caused by weakness or by reduced sensation; incomplete laryngeal vestibule closure, leading to penetration and reduced pharyngeal constriction with reduced movement on video fluoroscopy, may be caused by weakness or by a hypokinetic movement disorder (eg, Parkinson disease with impaired motor control); for these patients, skill-based exercises that improve range of motion are more likely to give benefit compared with strength exercises; a thorough examination includes a cranial nerve examination and listening to speech and cough; a patient with the same presentation but with a history of chemoradiation likely has fibrosis that reduces the range of motion; stretching exercises that improve tissue mobility are more appropriate for this patient

Identifying primary and secondary factors: more than 1 underlying pathogenesis may contribute to functional impairment; focus treatment efforts on specific factors; cough and swallowing therapy exercises should be selected using information synthesized from clinical evaluation and instrumental assessments; actual pathophysiology and functional impairments are identified from instrumental assessments; these help in determining target areas, eg, opening of the upper esophageal sphincter, laryngeal vestibule closure, reduction of the frequency and amount of aspiration; clinical profiling is used to develop an educated hypothesis on the potential cause or pathogenesis of the dysphasia; according to speaker, this element of the assessment helps determine the therapy required (ie, instrumental assessments determine the “what,” and clinical profiling [ie, CSE] determines the “how”)

Steps in developing exercises: develop an educated hypothesis on the underlying pathogenesis; consider secondary factors that might be contributing to the pathogenesis (eg, weakness resulting from disuse atrophy after radiation); the suspected pathogenesis guides the class of exercise in the intervention plan; classes of exercises include skill-based approaches, strengthening approaches, and stretching and manual therapy exercises

Strengthening exercises: expiratory muscle strength training is a newer type of therapy; a case series from Scripps MD Anderson Cancer Center showed the effect size was small to moderate, but it might be meaningful for individual patients; there is ongoing research into strength-based exercises, eg, chin tuck and jaw opening against resistance (nonswallowing strength-based exercises); the effortful swallow can be considered a strength-based exercise or a skill-based exercise; not all strengthening exercises are effective for each patient; a randomized controlled trial (Dotevall et al [2022]) showed that the Shaker head-lift exercise did not improve swallow function; consider the muscles to be targeted from a strengthening standpoint; the researchers did not measure changes in head-lift strength

Skill-based exercises: respiratory-swallowing coordination training is used for patients who breathe out before and/or after swallowing more frequently than normal; this therapy aims to train patients in the swallow-exhale pattern, targeting a specific lung volume; improvements in swallowing physiology are visible on video fluoroscopy, and there are improvements in pharyngeal residue penetration and aspiration; swallowing-driven exercises are part of larger protocols, eg, McNeil dysphagia therapy program and “pharyngocise” that improve swallowing function; skill-based exercises may work by teaching patients with decreased tissue pliability new ways to swallow with their new anatomy

Stretching exercises: consider tissue mobility and range of motion (eg, trismus after radiation therapy); a study (Silbergleit et al [2020]) showed that neck stretches may increase range of motion of the neck, but the results were not generalizable to functional swallowing outcomes; improving neck pliability may be important from a standpoint of positional strategy and have secondary effects on swallowing improvement; manual therapy may also facilitate improvements in radiation-related fibrosis

Designing therapy approach: use the results of CSE and instrumental assessment to determine the target, class of exercise, and the starting point (ie, proactive vs reactive); determine the goals of therapy prior to initiation; consider the desired intensity of the therapy; determine exercise-specific outcome measures (eg, continuously monitor effects on tongue strength with lingual resistance training); use those results to guide any needed changes in approach; target and monitor adherence; consider ways in which adherence can be improved; proactive prophylactic therapy — earlier and more intense interventions tend to lead to better outcomes from standpoints of stretching- and functional swallowing outcome (a multicenter study is ongoing)

Barriers to completion of therapy: therapy-related pain and time requirements are significant barriers; a mobile application has been developed to track and encourage increased adherence to swallowing interventions in patients who have undergone or are currently undergoing radiation therapy; repeat instrumental assessments at the end of therapy show any changes in cough and swallowing; if patients are not responding, the clinician may advise switching to another exercise or facilitate improvements in exercises

Readings

Banda KJ, Chu H, Kao CC, et al. Swallowing exercises for head and neck cancer patients: A systematic review and meta-analysis of randomized control trials. Int J Nurs Stud. 2021;114:103827. doi:10.1016/j.ijnurstu.2020.103827; Baudelet M, Duprez F, Van den Steen L, et al. Increasing adherence to prophylactic swallowing exercises during head and neck radiotherapy: The multicenter, randomized controlled PRESTO-trial. Dysphagia. 2023;38(3):886-895. doi:10.1007/s00455-022-10513-6; Diaz K, Stegemöller EEL. Electromyographic measures of asymmetric muscle control of swallowing in Parkinson's disease. PLoS One. 2022 Feb 18;17(2):e0262424. doi: 10.1371/journal.pone.0262424. PMID: 35180221; PMCID: PMC8856551; Dotevall H, Tuomi L, Petersson K, et al. Treatment with head-lift exercise in head and neck cancer patients with dysphagia: results from a randomized, controlled trial with flexible endoscopic evaluation of swallowing (FEES). Support Care Cancer. 2022;31(1):56. Published 2022 Dec 17. doi:10.1007/s00520-022-07462-z; Guillen-Sola A, Soler NB, Marco E, et al. Effects of prophylactic swallowing exercises on dysphagia and quality of life in patients with head and neck cancer receiving (chemo) radiotherapy: the Redyor study, a protocol for a randomized clinical trial. Trials. 2019;20(1):503. Published 2019 Aug 14. doi:10.1186/s13063-019-3587-x; Hutcheson KA, Barrow MP, Plowman EK, Lai SY, Fuller CD, Barringer DA, Eapen G, Wang Y, Hubbard R, Jimenez SK, Little LG, Lewin JS. Expiratory muscle strength training for radiation-associated aspiration after head and neck cancer: A case series. Laryngoscope. 2018 May;128(5):1044-1051. doi: 10.1002/lary.26845. Epub 2017 Aug 22. PMID: 28833185; PMCID: PMC5823707; Kotz T, Federman AD, Kao J, et al. Prophylactic swallowing exercises in patients with head and neck cancer undergoing chemoradiation: a randomized trial. Arch Otolaryngol Head Neck Surg. 2012;138(4):376-382. doi:10.1001/archoto.2012.187; Krekeler BN, Rowe LM, Connor NP. Dose in exercise-based dysphagia therapies: A scoping review. Dysphagia. 2021;36(1):1-32. doi:10.1007/s00455-020-10104-3; McAllister S, Tedesco H, Kruger S, et al. Clinical reasoning and hypothesis generation in expert clinical swallowing examinations. Int J Lang Commun Disord. 2020;55(4):480-492. doi:10.1111/1460-6984.12531; Open Science Collaboration. PSYCHOLOGY. Estimating the reproducibility of psychological science. Science. 2015;349(6251):aac4716. doi:10.1126/science.aac4716; Pauloski BR. Rehabilitation of dysphagia following head and neck cancer. Phys Med Rehabil Clin N Am. 2008;19(4):889-x. doi:10.1016/j.pmr.2008.05.010; Silbergleit AK, Schultz L, Krisciunas G, et al. Association of neck range of motion and skin caliper measures on dysphagia outcomes in head and neck cancer and effects of neck stretches and swallowing exercises. Dysphagia. 2020;35(2):360-368. doi:10.1007/s00455-019-10037-6; Simental AA, Carrau RL. Assessment of swallowing function in patients with head and neck cancer. Curr Oncol Rep. 2004;6(2):162-165. doi:10.1007/s11912-004-0028-z; Stenson KM, MacCracken E, List M, et al. Swallowing function in patients with head and neck cancer prior to treatment. Arch Otolaryngol Head Neck Surg. 2000;126(3):371-377. doi:10.1001/archotol.126.3.371.

Disclosures

For this program, members of the faculty and planning committee reported nothing relevant to disclose.

Acknowledgements

Dr. Curtis was recorded at Updates in the Management of Head and Neck Disease, held November 10-12, 2022 in San Francisco, CA, and presented by the University of California, San Francisco, School of Medicine. For information about upcoming CME activities from this presenter, please visit https://cme.usf.edu. Audio Digest thanks Dr. Curtis and the University of California, San Francisco, School of Medicine for their cooperation in the production of this program.

CME/CE INFO

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The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 1.75 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

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Lecture ID:

OT562001

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.