Dysphagia: Terminology, structure, and process of the normal swallow

1. Dysphagia: Terminology, structure, and process of the normal swallow Scott S. Rubin, Ph.D. Associate Professor, LSUHSC-NO SPTHAUD 6218

2. The Swallow: Structure and processes • Text for this semester - • Groher, M., & Crary, M. (2010). Dysphagia: Clinical Management in Adults and Children (3rdEdition), Mosby/Elsevier. • ISBN: 978-0-323-05298-6

3. The Swallow: Structure and processes • Presentation topics include: • SLP involvement • What is Dysphagia (definitions) • Structures associated with swallow • Neurological control of swallow • Stages of normal swallow

4. The Swallow: Structure and processes • According to ASHA • Service delivery in the area of swallowing and feeding (i.e., dysphagia) • a significant portion of the caseload of speech-language pathologists in health care settings. • Respondents to the 2002 ASHA Omnibus Survey reported – • dysphagia services - provided by 90% of SLPs in residential health care • 84% in hospitals • 50% in non-residential health care • 11% in schools. • In recent ASHA Speech-Language Pathology Health Care Survey (2002) - • respondents in adult health care settings reported spending 31% of their time in the delivery of services related to dysphagia

5. ASHA Preferred Practice • Link to ASHA Preferred Practice Patterns for the Profession of Speech-Language Pathology • http://www.asha.org/docs/html/PP2004-00191.html • Please familiarize yourself with it!!!

6. The Swallow: Structure and processes • What is Dysphagia? • ASHA SID pronunciation - dysphagia (dis-FAY-juh) • Common: (dis-FA-juh) – for a good reason! • Definitions - • Somewhat vague and over inclusive? • Difficulty swallowing. (or feeding?) • Less debatable - • A swallowing disorder; difficulty in swallowing or the inability to swallow; condition in which swallowing is difficult or painful.

7. The Swallow: Structure and processes • What is Dysphagia? • Those with dysphagia may experience pain while swallowing. Some people may be completely unable to swallow or may have trouble swallowing liquids, various consistencies of foods, and/or saliva. • Eating becomes a challenge and filled with fear or anticipation of problems.

8. The Swallow: Structure and processes • Dysphagia (continued) • Dysphagia may cause difficult in taking in enough calories (food and fluids) to nourish the body. • Lasting dysphagia can lead to serious health problems and death. • Also, if managed poorly by SLP – can contribute to poor outcome!

9. The Swallow: Structure and processes • Common classifications of dysphagia • Oral phase–sucking, chewing, and moving food or liquid into the throat (usually subdivided to Oral Preparatory and Oral Transit) • Pharyngeal phase–starting the swallowing reflex, squeezing food down the throat, and closing off the airway to prevent food or liquid from entering the airway (aspiration) or to prevent choking • Esophageal phase–relaxing and tightening the openings at the top and bottom of the feeding tube in the throat (esophagus) and squeezing food through the esophagus into the stomach • Topic for later presentation

10. The Swallow: Structure and processes • Associated Terminology • Penetration – Material moves into vestibule above the true vocal folds • Aspiration –Material breaches vocal folds into trachea and potentially into lungs. • Silent Aspiration – occurs but no signs/symptoms The risk for aspiration is not limited to meal times. It can occur ANY TIME, day or night. Includes food, drink, medication, saliva, and vomit • Potential Consequences of Aspiration • Pneumonia (i.e., Aspiration Pneumonia) • Perminant Lung Damage • Death!

11. The Swallow: Structure and processes • Dysphagia Triggers - Symptoms or signs that may signal the occurrence of aspiration • Coughing – forceful exhalation of air • Choking – airway is blocked • GERD/Reflux – stomach contents come back up into esophagus or mouth • Much more terminology presented in context.

12. Anatomy and Physiology of the Normal Swallow

13. The Swallow: Structure and processes • Cranial Nerves Important in Swallowing • CN V Trigeminal • CN VII Facial • CN IX Glossopharyngeal • CN X Vagus • CN XII Hypoglossal • Each Nerve on following slides… • And … other nerves? Impact? – explore on own and have examples (could be on exam or comps)! • Vision • Smell • Eye movement…

14. The Swallow: Structure and processes • Cranial Nerves Important in Swallowing • CN V -- Trigeminal • sensory and motor- innervates the face • important in chewing • located at the level of the pons

15. The Swallow: Structure and processes • CN V – Trigeminal • 3 Branches • Opthalmic V1(sens) • Maxillary V2 (sens) • Mandibluar V3 (mixed) • Sensory from forehead and eye – (over V1), cheek (over V2) and • lower face and jaw (V3). • Motorfor muscles of mastication, • soft palate, mylohyoid , chin

16. The Swallow: Structure and processes • Cranial Nerves Important in Swallowing • CN VII -- Facial  • sensory and motor fibers • important for sensation of oropharynx & taste to anterior 2/3 of tongue

17. The Swallow: Structure and processes • CN VII -- Facial  • Facial nerve proper:The largest component of the facial nerve. Voluntary control of the muscles of facial expression, as well as the posterior belly of the digastric, stylohyoid and stapedius muscles.

18. CN VII -- Facial  • Nervous Intermedious carries rest of sensory fibers and autonomic information. • Yellow = F. nerve Proper. • Orange, Blue, Green = Nerv. Intermedious

19. The Swallow: Structure and processes • Cranial Nerves Important in Swallowing • CN IX -- Glossopharyngeal • contains both sensory and motor fibers • important for taste from posterior tongue, sensory and motor functions of the pharynx

20. The Swallow: Structure and processes • Cranial Nerves Important in Swallowing • CN IX – Glossopharyngeal • It receives sensory fibers from: posterior one-third of the tongue, tonsils, Pharynx, middle ear, and the carotid body. • Autonomic fibers to the parotid gland • It also supplies motor fibers to stylopharyngeus muscle and the upper pharyngeal muscles.

21. The Swallow: Structure and processes • Cranial Nerves Important in Swallowing • CN X -- Vagus • contains both sensory and motor fibers • important for taste to oropharynx, and sensation and motor function to larynx and laryngopharynx. • important for airway protection

22. The Swallow: Structure and processes • CN X - Vagus - 3 branches • Pharyngeal Nerve branch • Motor and sensory fibers • Motor to soft palate and pharynx • Sensory to lower pharynx • Superior Laryngeal N. Branch – has 2 branches • Internal laryngeal nerve • Sensory from epiglottis and interior larynx • External laryngeal Nerve • Motor to cricothyroid muscle and inferior constrictor muscle • Recurrent Laryngeal N.B.

23. The Swallow: Structure and processes • CN X - Vagus - 3 branches • Recurrent Laryngeal Branch Courses past larynx – neck and upper chest – then from chest up to larynx • innervates all muscles of the larynx (except Cricothyroid)

24. The Swallow: Structure and processes • Cranial Nerves Important in Swallowing • CN XII -- Hypoglossal • contains motor fibers that primarily innervate the tongue

25. The Swallow: Structure and processes • CN XII -- Hypoglossal To all Intrinsic Muscles of Tongue And all but one Extrinsic

26. Anatomy of Swallow

27. The Swallow: Structure and processes • Anatomy of Swallow • Skeleton • Hyoid Bone - attachment to epiglottis and strap muscles. • Thyroid Cartilage - anterior attachment of vocal folds. Posterior articulation with cricoid cartilage.

28. The Swallow: Structure and processes • Anatomy of Swallow • Skeleton • Cricoid Cartilage - complete ring. Articulates with thyroid and arytenoid cartilages. • Arytenoids - two cartilages which glide along the posterior cricoid and attach to posterior ends of vocal folds.

29. The Swallow: Structure and processes Divisions of Structure • Supraglottis - usually covered with respiratory epithelium containing mucous glands. • Epiglottis - leaf-shaped mucosal-covered cartilage, which projects over larynx. • Aryepiglottic folds - extend from the lateral epiglottis to the arytenoids. • False vocal cords - mucosal folds superior to the true glottis. Separated from true vocal folds by the ventricle. • Ventricle - mucosal-lined sac, variable in size which separates the supraglottis from the glottis.

30. The Swallow: Structure and processes Divisions of Structure • Glottis – • true vocal folds attach to the thyroid cartilage at the anterior commissure. • The posterior commissure is mobile, as the vocal folds attach to the arytenoids. • Motion of the arytenoids effects abduction or adduction of the larynx. • The bulk of the vocal fold is made up of muscle covered by mucosa. • The vocal folds abduct for inspiration and adduct for phonation& cough

31. The Swallow: Structure and processes Divisions of Structure • Subglottis - below the vocal folds

32. Pyriform Sinus The Swallow: Structure and processes

33. Valleculae The Swallow: Structure and processes

34. Vallecula Note aspiration in trachea. The Swallow: Structure and processes

35. Review of Structures • Vallecula • Epiglottis • Upper Esophageal Sphincter (UES) • Lower Esophageal Sphincter (LES) The Swallow: Structure and processes

36. Watch the structures! “Want that pizza to go? The Swallow: Structure and processes

37. The Swallow: Structure and processes • Glands • Parotid Gland • Located on side of face, anterior to mastoid tip and superior to the lower • Facial nerve passes through this gland.

38. The Swallow: Structure and processes • Submandibular Gland • Beneath floor of the mouth

39. The Swallow: Structure and processes • Sublingual Glands - located below the mucous membrane of the floor of the mouth, adjacent to mandible and mylohyoid muscle.

40. The Swallow: Structure and processes • Minor Salivary Glands - small collections of salivary gland tissues are scattered throughout the oral mucosa, and can also be seen in the pharynx, supraglottis, nose and sinuses.

41. Stages of the normal swallow

42. Stages of the normal swallow (Oral Prep Phase) - Oral Phase - Pharyngeal Phase - Esophageal Phase

43. The Swallow: Structure and processes • Oral Phase • Oral Preparatory • Goal: reduce food to a bolus and position it for transport • Initial transport (the bolus lacement) - tongue positions the food to ready it for reduction • Reduction phase - bolus is chewed & mixed with saliva • Bolus placement - bolus is positioned for transport • Oral Transport • The prepared bolus is transported from anterior to posterior oral cavity for passage to the pharynx.

44. The Swallow: Structure and processes • Pharyngeal Phase • Complete closure of velopharyngeal opening. • Hyoid & Larynx begin their superior ascent • Epiglottis begins to fold down – back. • (to clarify - the epiglottis tilting or folding back and down is as the result of surrounding structures’ movement – i.e., larynx elevating, contracting mouth floor, & hyoid moving up and back) . • Tongue base to posterior pharyngeal wall contact • Top to bottom contractions of pharyngeal constrictor muscles • Continued superior movement of hyoid & larynx • Laryngeal closure starts from bottom up • Continued down-folding of epiglottis to inverted position • Anterior movement of hyoid • Relaxation of cricopharygeus muscle & opening of upper esophageal sphincter region

45. The Swallow: Structure and processes • Esophageal Phase • Peristalsis carries the bolus through esophagus to the stomach. • The lower espohageal sphincter opens.

46. Summary of the Swallow “Swallow Reloaded”

47. The Swallow: Structure and processes • FIGURE 1A. ORAL Phase - The tongue initially forms the food bolus (green) with compression against the hard palate.

48. The Swallow: Structure and processes • FIGURE 1B. PHARYNGEAL Phase Displacement of the food bolus into the pharynx by the tongue initiates deglutition

49. The Swallow: Structure and processes • FIGURE 1C. ESOPHAGEAL Phase - Relaxation of the cricopharyngeal muscle (the physiological upper esophageal sphincter) permits movement of the food bolus into the proximal esophagus.

50. The Swallow: Structure and processes • The Swallow • Videofluoroscopy Segments