Cognitive and Language Impairments in Dysphagia Rehabilitation

Educational Objectives

The goal of this program is to improve management of dysphagia in patients with cognitive and neurologic impairments. After hearing and assimilating this program, the clinician will be better able to:

1. Educate patients regarding influences of cognitive impairment on swallowing.
2. Apply best practice guidelines for patients with various levels of cognitive impairment.
3. Incorporate sensory enhancement therapy for patients with dysphagia.

Summary

Introduction: a patient can only properly swallow when all 5 dysphagia systems (ie, neurologic, cognitive, respiratory, gastrointestinal, muscular) are working together (Winchester et al [2016]); dysphagia occurs when ≥1 system malfunctions; neurologic dysphagia results from a breakdown in the central nervous system, affecting motor and sensory functions and impairing swallowing safety or efficiency; cognitive dysphasia occurs when cognitive decline precedes or results in system breakdown; neurologic and cognitive dysphagia can coexist and exacerbate breakdown; cognitive communication impairments often cooccur with dysphagia; one study found that patients referred to speech-language pathology for dysphagia evaluation also have impairments in communication and swallowing; ≤27% of patients have aphasia and dysphagia after initial ischemic stroke; concurrent dysphagia and aphasia is associated with increased mortality and longer length of stay, compared with patients with neither or one condition (Guyomard et al [2009]); several studies demonstrate that cognitive impairment (CI) is associated with severity of dysphagia; more severe CI following stroke, specifically deficits in visual attention and executive function, are associated with oral-based deficits; for individuals with dementia, attention is linked with dysphagia; Leder et al (2009) demonstrated a strong correlation between CI and aspiration risk; patients disoriented to person, place, or time were 31% more likely to aspirate liquids; patients unable to follow 1-step commands were 57% more likely to aspirate liquids, 48% more likely to aspirate purees, and 69% more likely to be deemed unsafe for oral intake

Management: most effective, evidence-based treatments for dysphagia require cognitive abilities; many studies on dysphagia treatments exclude patients with CI or do not comment on cognitive or language deficits; swallowing therapy often involves cognitive control for initiating and modulating movements, and patients with cortical or cognitive deficits may require alternative treatment approaches; the two components of treatment involve treating the cognitive or linguistic deficit and exploring sensory enhancement and principles of neuroplasticity and exercise science (for patients in whom traditional swallowing techniques are not feasible)

Cognitive and linguistic treatment: the American Congress of Rehabilitation Medicine has established best practices for cognitive rehabilitation based on a systematic review by Cicerone et al (2019) in patients with acquired brain injury; several guidelines exist for stroke; for patients with language impairments, formal language assessments are recommended, including testing of verbal and written expression, auditory and reading comprehension, and pragmatics; intensive speech-language therapy is recommended for patients with aphasia and should include components of communication partner training; early cognitive screening is recommended for all patients, and those with positive screening should undergo in-depth neuropsychological testing to assess the cognitive domains of attention, memory, executive function, apraxia, and visual neglect; comprehensive cognitive treatment is recommended for patients with CI and should include domain-specific treatment and metacognitive strategies (for mild to moderate CI) or errorless learning (for severe CI); external modifications may be necessary to maximize therapeutic benefits; always complete an objective swallow test first to define the level of impairment and inform treatment

Sensory enhancement: refers to the manipulation of the sensory components of a bolus in order to improve motor output

Viscosity: considered a compensatory strategy; compared with thin liquids, studies demonstrate that thicker liquids provide different sensory input and move more slowly, allowing impaired muscles more time to respond; Bisch et al (1994) demonstrated improvements in pharyngeal delay time among patients with neurologic impairments who consumed drinks with increased vs regular viscosity; Clavé et al (2006) found that increasing viscosity from thin to nectar or pudding improves overall swallowing safety and efficiency (ie, reduced penetration, aspiration, and extent of residue) in patients with brain damage and neurodegenerative conditions; Garand et al (2024) found that pudding bolus improves anterior hyoid excursion, epiglottic movement, pharyngeal stripping wave, and pharyngoesophageal segment opening, while thin liquid bolus improves tongue base contraction; compared with patients who underwent classical dysphagia therapy (CDT) alone, Wang et al (2023) demonstrated nasogastric tube removal in all patients who underwent swallow training with xanthan gum plus CDT; patients who underwent swallow training also demonstrated improved functional oral intake scores

Carbonation: Shapira-Galitz et al (2021) demonstrated decreased penetration-aspiration scale (PAS) scores and decreased food residue among patients consuming carbonated vs noncarbonated thin liquids; combining carbonation with thickened liquids may enhance sensory input to the oropharyngeal and laryngeal senses, leading to better swallowing activation and potentially stimulating the cortical and brainstem swallowing networks; studies have shown that carbonated thickened liquids may reduce PAS scores, trigger earlier swallowing initiation (vs thin liquids), and decrease food residue (vs noncarbonated thickened liquids); additionally, patients often find carbonated thickened liquids easier to swallow than noncarbonated liquids

Taste: taste diminishes with age; neurologic conditions further reduce sensory perception; while unpleasant, sour tastes can stimulate saliva production, increase bolus volume, and trigger a quicker swallow response time; compared with a nonsour bolus, evidence demonstrates that a sour food bolus can improve oral transit time (OTT) and oropharyngeal swallow efficiency, reduce food residue and PAS score, and increase the amount of spontaneous swallows after the initial swallow; Logemann et al (1995) suggest incorporating 1 mL sour liquid or sugarless sour candies into therapy protocols for patients with neurologic impairments to facilitate swallowing function

Taste and temperature: Gatto et al (2013) demonstrated improvements in pharyngeal transit time and OTT with combined use of sour taste and cold temperature in patients with oropharyngeal dysphagia following ischemic stroke; when offered in a random order, the sour-cold bolus increases response to subsequent boluses (Gatto et al [2021])

Volume: Pelletier et al (2003) demonstrated reduced penetration and aspiration with teaspoon delivery vs cup delivery of thin liquid boluses; they also found that the majority of patients who aspirate initial larger boluses exhibit self-modulation with subsequent boluses and safer subsequent swallows; additional studies found that increasing bolus volume may decrease pharyngeal delay through increased sensory input; one study found that increased bolus volume decreases swallowing safety and efficiency; consider objective findings on imaging to determine optimal bolus material; many studies demonstrate positive results with gradual volume increments; none of these techniques have been shown to improve hyolaryngeal excursion or laryngeal vestibule closure

Incorporation of the principles of neuroplasticity: encourage frequent swallowing in a safe way and with proper form; incorporate therapeutic, everyday foods and sensory enhancement techniques; repetition is important; start as soon as possible following diagnosis of dysphagia; consider patient sensory preferences

Readings

Bisch EM, Logemann JA, Rademaker AW, et al. Pharyngeal effects of bolus volume, viscosity, and temperature in patients with dysphagia resulting from neurologic impairment and in normal subjects. J Speech Hear Res. 1994;37(5):1041-59. doi:10.1044/jshr.3705.1041; Clavé P, de Kraa M, Arreola V, et al. The effect of bolus viscosity on swallowing function in neurogenic dysphagia. Aliment Pharmacol Ther. 2006;24(9):1385-1394. doi:10.1111/j.1365-2036.2006.03118.x; Garand KLF, Armeson K, Hill EG, et al. Quantifying oropharyngeal swallowing impairment in response to bolus viscosity. Am J Speech Lang Pathol. 2024;33(1):460-467. doi:10.1044/2023_AJSLP-23-00082; Gatto AR, Cola PC, da Silva RG, et al. Influence of thermal and gustatory stimulus in the initiation of the pharyngeal swallow and bolus location instroke. J Stroke Cerebrovasc Dis. 2021;30(4):105349. doi:10.1016/j.jstrokecerebrovasdis.2020.105349; Gatto AR, Cola PC, Silva RG, et al. Sour taste and cold temperature in the oral phase of swallowing in patients after stroke. Codas. 2013;25(2):164-168. doi:10.1590/s2317-17822013000200012; Guyomard V, Fulcher RA, Redmayne O, et al. Effect of dysphasia and dysphagia on inpatient mortality and hospital length of stay: a database study. J Am Geriatr Soc. 2009;57(11):2101-6. doi:10.1111/j.1532-5415.2009.02526.x; Leder SB, Suiter DM, Lisitano Warner H. Answering orientation questions and following single-step verbal commands: effect on aspiration status. Dysphagia. 2009;24(3):290-295. doi:10.1007/s00455-008-9204-x; Middleton EL, Schwartz MF. Errorless learning in cognitive rehabilitation: a critical review. Neuropsychol Rehabil. 2012;22(2):138-168. doi:10.1080/09602011.2011.639619; Nagano A, Maeda K, Shimizu A, et al. Effects of carbonation on swallowing: systematic review and meta-analysis. Laryngoscope. 2022;132(10):1924-1933. doi:10.1002/lary.30019; Pelletier CA, Lawless HT. Effect of citric acid and citric acid-sucrose mixtures on swallowing in neurogenic oropharyngeal dysphagia. Dysphagia. 2003;18(4):231-41. doi:10.1007/s00455-003-0013-y; Shapira-Galitz Y, Levy A, Madgar O, et al. Effects of carbonation of liquids on penetration-aspiration and residue management. Eur Arch Otorhinolaryngol. 2021;278(12):4871-4881. doi:10.1007/s00405-021-06987-z; Silverberg ND, Iverson GL; ACRM Brain Injury Special Interest Group Mild TBI Task Force members, et al. The American Congress of Rehabilitation Medicine Diagnostic Criteria for mild traumatic brain injury. Arch Phys Med Rehabil. 2023;104(8):1343-1355. doi:10.1016/j.apmr.2023.03.036; Wang Y, Zhang J, Zhu HM, et al. The therapeutic effect of swallow training with a xanthan gum-based thickener in addition to classical dysphagia therapy in Chinese patients with post-stroke oropharyngeal dysphagia: a randomized controlled study. Ann Indian Acad Neurol. 2023;26(5):742-748. doi:10.4103/aian.aian_139_23.

Disclosures

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

Acknowledgements

Ms. Berube was recorded at Johns Hopkins Dysphagia Symposium 2024, held virtually on September 20-21, 2024, and presented by The Johns Hopkins University School of Medicine. For information on upcoming CME activities from this presenter, please visit https://hopkinscme.cloud-cme.com. Audio Digest thanks the speakers and The Johns Hopkins University School of Medicine for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

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 1.00 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 1.00 CE contact hours.

Lecture ID:

OT580102

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.