Swallowing Disorders Flashcards
(44 cards)
Obj: Identify the phases of swallowing and correct order
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Obj: Given Signalment and CS, localize the site of dysphagia and formulate and prioritize a DDx list and Dx plan
Obj: Describe the clinical importance of differences in esophageal structure between species
Obj: Using imaging findings prioritize DDx for a patient with esophageal dysphagia
Obj: For specific diseases, formulate the most appropriate treatment plan and communicate complication and prognostic information to owners
What are the phases of swallowing
- Oral
- Pharyngeal
- Esophageal
Define Dysphagia
Difficult or painful swallowing
What is the diagnostic approach for dysphagia
- Complete history
- Physical and ORAL examination
- Observation of eating
- Neuro Exam
- Disease Localization
What happens during the oral phase of swallowing?
- Voluntary control
- Prehension of food
- Separation of bolus from bulk of food with tongue
- Pressure of tongue on hard palate ⇢ Caudodorsal movement of bolus
- Bolus in the pharynx initiates the swallowing reflex
What are the clinical signs of Oral Dysphagia?
- Ptyalism
- Chewing on one side
- Dropping food
- Excessive head movements during prehension
- Submerge muzzle to eat/drink
what is the diagnostic approach for Oral Dysphagia?
- Sedated Exam +/- Radiographs
- anatomic defects: Cleft palate
- Periodontal diseases/stomatitis
- Obstructive disease
What happens during the Pharyngeal phase of Swallowing?
- Reflex inhibition of breathing
- Pharynx narrows to move bolus caudally
- Relaxation of upper esophageal sphincter (UES)
- Constriction of pharynx ⇢ Bolus forced into caudal pharynx/through UES
What are the clinical signs of Pharyngeal/Cricopharyngeal Dysphagia?
- Repeated swallowing attempts
- Excessive neck movements during swallowing
- Gagging
- Coughing or immediate reflux of food/water
- Ptyalism
What is the diagnostic approach for Pharyngeal/Cricopharyngeal Dysphagia
- Radiographs (Oral/skull, cervical)
- Contrast Fluoroscopy
- Congenital cricopharyngeal achalasia
- Neuropathies: central or peripheral
- NMJ disorders: Myasthenia gravis
- Muscle disorders: muscular dystrophy, myositis
What is Cricopharyngeal Achalasia/Asynchrony?
- Congenital neuromuscular disorder in which the UES either:
- fails to relax (achalasia)
- Relaxation is discordant with pharyngeal contraction (asynchrony)
What is the common signalment of Cricopharyngeal Achalasia/Asynchrony?
- Young: weaning
- Breeds:
- Golden Retriever
- Cocker and Springer Spaniels
- Miniature Dachshunds
What are the clinical signs of Cricopharyngeal Achalasia/Asynchrony?
- Pharyngeal/Cricopharyngeal dysphagia
- Poor BCS, slow growth
- Aspiration pneumonia
How is Cricopharyngeal Achalasia/Asynchrony diagnosed?
- Contrast Radiography
- Fluoroscopy
- +/- serum creatine kinase, EMG, muscle biopsies
What is the treatment for Cricopharyngeal Achalasia/Asynchrony?
- Surgical myotomy of cricopharyngeal muscle
- Botulinum toxin injection
- Supportive care:
- Nutrition - Esophageal/gastric feeding tubes
- Pneumonia treatment
What happens during the Esophageal phase of Swallowing
- Constriction of UES (after bolus passes)
- Initial peristaltic wave moves from UES through entire esophageal length (Primary peristalsis)
- Incomplete food clearance ⇢ Esophageal distention ⇢ Secondary peristalsis
- Reflex relaxation of lower esophageal sphincter (LES)
Describe the structure of the Esophagus
- UES: Striated muscle
- Body:
- Dog – striated muscle
- Cat – Proximal ⅓ striated, distal ⅓ smooth muscle
- LES: smooth muscle
- Innervation: Vagus n. and branches
What is the diagnostic approach for Esophageal Dysphagia?
- Thorough history (Regurgitation*)
- Complete PE and Neuro eam
- Radiographs (cervical, thoracic)
- Generalized esophageal dilation: Megaesophagus
- Focal dilation: Stricture, diverticulum, vascular ring anomaly
- Radiopaque structure: foreign body
- Normal/non-diagnostic
- Fluoroscopy: performed in sternal recumbency
- Stricture
- Intraluminal mass
- Dysmotility or gastroesophageal reflux
- Normal → Esophagoscopy
- Fluoroscopy: performed in sternal recumbency
What is the difference between Megaesophagus and Esophageal Dysmotility?
- Megaesophagus:
- diffuse esophageal dilation and association of peristalsis
- Dysmotility:
- Decreased esophageal peristalsis or retrograde movement of food bolus w/out diffuse dilation
What are the Etiologies of Generalized Megaesophagus?
- Congenital:
- Idiopathic: Possible Vagal n. defect
- Congenital Myasthenia gravis (MG) or Hypothyroidism
- Acquired:
- Idiopathic
- Endocrine disease
- Neurologic disease
- Esophagitis
- Toxicity
- Thymoma (paraneoplastic)