Anatomy & Physiology of Mastication and Deglutition

Swallow Screening

10-15 minute Bedside clinical assessment Medical history Level of alertness Pt interview Oral motor exam Assess swallow with small bolus Signs & symptoms Spillage? Oral residue? Cough? Gurgly voice? Cannot assess A & P Pre-diagnostic

Signs and Symptoms of Oral or pharyngeal dysphagia

Coughing or choking with swallowing Difficulty initiating swallowing Food sticking in the throat Sialorrhea / xerostomia Drooling or spillage Unexplained weight loss Change in dietary habits Penetration Aspiration Recurrent pneumonia Change in voice or speech (wet voice) Nasal regurgitation Wet, gurgly voice quality

Consequences

Dehydration Malnutrition Aspiration pneumonia Quality of life

Treatments

Diet modification (volume, viscosity, texture, temperature, NPO diet - NG tube, G tube, PEG, J tube, TPN) Compensatory (Positional: posture, chin tuck, head rotation; Multiple swallows) Maneuver (Supraglottic, Super-supraglottic, Mendelsohn, Effortful) Exercise (Shaker, Masako, oral muscle strengthening) Prosthetic (Palatal lift or obturator) Surgery (CP myotomy, diverticulectomy, dilation) Experimental Deep Pharyngeal Neuromuscular Stimulation (DPNS) Neuromuscular electrical stimulation (NMES: "VitalStim") Indirect tx's vs. direct tx's

DYSPHAGIA

Difficulty swallowing Difficulty moving bolus from the mouth to the stomach Not age-specific (newborn>elderly) Etiologies: infection, structural malformations, surgery (thyroid/RLN), conditions that weaken/damage muscles/nerves (CVA, PD, TBI)

Young normal:

Higher hyoid & larynx (better protection), less elevation Lower velum, shorter pharynx Uvula in epiglottis, pocketing valleculae Pharyngeal swallow is triggered at anterior faucial arch (bolus flow uninterrupted, no pause)

Diagnostic Procedure

ID symptoms to explain abnormalities in anatomy or physiology causing dysphagia (etiology) Examines Physiology Timing, tongue base motion, epiglottic dysfunction, laryngeal excursion, UES dysfunction, peristalsis, paralysis, sensitivity Examines immediate effects of tx's Imaging: FEES/FEEST, videofluoroscopy*, ultrasound, videoendoscopy, scintigraphy Nonimaging: EMG, EGG, acoustic (accelerometer or stethoscope), pharyngeal manometry

Types of Dysphagia

Oral (tongue mvmt, lip closure, pocketing, transport) Pharyngeal (airway closure, residues, motility, UES) Oropharyngeal* Esophageal (motility, LES, fistula, diverticulum, HCl - reflux; ulcer)

Stages of Deglutition

Oral Stage Pharyngeal Stage Esophageal Stage

Older normal:

Ossification of cartilages & hyoid bone Pharyngeal swallow triggered when bolus head reaches middle of tongue base 70+ larynx lower Arthritis in C vertebrae impinge on pharyngeal wall Delay, residue, penetration Reduced hyolaryngeal excursion, plateaus at CP opening Reduced CP opening flexibility

Neurologic:

Pharyngeal swallow triggered when bolus head reaches middle of tongue base or when falls into pyriforms

Mastication:

Process of food preparation, including chewing food and mixing it with saliva in preparation for swallowing

Deglutition:

Process of swallowing

Facial (VII)

SENSORY (afferent): Taste anterior 2/3 of tongue MOTOR (efferent):Lips, face, salivary glands

Vagus (X)

SENSORY (afferent):Mucous membrane of pharynx, larynx, bronchi, lungs, esophagus, stomach MOTOR (efferent):Trachea, larynx, pharynx, cough reflex

V. Trigeminal Nerve

SENSORY (afferent):Sensation anterior 2/3 of tongue MOTOR (efferent): Mastication

Hypoglossal (XII)

SENSORY (afferent):Sensation, mucous membranes of pharynx, palate, post. tongue & tonsils MOTOR (efferent):Tongue;Pharynx, gag reflex

Glosso-pharyngeal (IX)

SENSORY (afferent):Taste & sensation post. 1/3 of tongue MOTOR (efferent):Uvula, palate, pharyngeal constrictors

Multidisciplinary Dysphagia Team

SLP Physician / Neurologist / ENT Nursing Dietician OT PT Radiologist Pharmacist Social worker Psychologist

Signs and symptoms of Esophageal dysphagia

Sensation of food sticking in the chest or throat Oral or pharyngeal regurgitation Change in dietary habits Recurrent pneumonia Reflux Aspiration SILENT ASPIRATION (no signs)

Pharyngeal Stage

Sometimes called oropharyngeal a. Velum elevates & retracts for VP closure, bolus transport with tongue base retraction & pharyngeal wall contraction b. Epiglottis inverts, hyolaryngeal elevation & protraction c. Closure of larynx, respiration ceases (apneic period) d. UES opening e. Transport by pharyngeal constrictors f. UES closure, larynx rests Lasts ~1 second

Cranial Nerves of Swallowing

Trigeminal Nerve (V) Facial (VII) Hypoglossal (XII) Vagus (X) Glosso-pharyngeal (IX)

Swallowing Variations

Young normal Older normal Neurologic

Oral stage

begins when bolus is prepared for swallowing Back of tongue drops down and pulls posteriorly Mastication stops Anterior tongue elevates to hard palate and squeezes the bolus back Bolus contact with fauces stimulates reflexes of pharyngeal stage

olfaction

smell Seventy to seventy-five percent of what we perceive as taste actually comes from our sense of smell

Gustation

taste Taste buds allow us to perceive only bitter, salty, sweet, sour and savory flavors The odor molecules from food give us most of our taste sensation

Esophageal Stage

transit time is measured from UES through LES (8-20 seconds) bolus flow through the esophagus via peristaltic contractions of striated and smooth muscle along the esophageal wall relaxation of LES allows bolus to flow into the stomach