8.1.1 Swallowing

Question 1

Swallowing is thought to have?

Answer 1

Bi-lateral innervation from the corticobulbar tracts

Question 2

Describe the preparatory phase of swallowing.

Answer 2

Preparation

Muscles of mastication

CN 5, 7, 12

Voluntary

Indirectly affects swallowing

Question 3

What are the roles of the various cranial nerves involved in swallowing?

Answer 3

medulla

Hypoglossal nucleus - CN XII controls motor movement of the tongue

Solitary nucleus - CN IX involved in sensory control used to initiate swallowing

Nucleus ambiguous - CN X Motor control

Question 4

Aspiration pneumonia is caused by?

Answer 4

Aspiration of salvia

Question 5

Describe the esophageal phase of swallowing.

Answer 5

Peristaltic propulsion of bolus down the esophagus

Question 6

Describe the pharyngeal phase of swallowing.

Answer 6

1. Closure of the vocal folds and the laryngopharyngeal vestibule
2. Elevation of the larynx, accompanied by lowering of the epiglottis over the laryngeal vestibule
3. Peristaltic contraction of the pharyngeal constrictor muscles
4. Relaxation of the cricopharyngeus muscle (CN X)

Question 7

Describe the oral phase of swallowing.

Answer 7

1. Elevation of the tongue to the palate and propulsion of bolus by the tongue into the pharynx
2. Closure of the soft palate against the pharyngeal wall to prevent nasal reflux.

Question 8

Describe what causes nasal reflux.

Answer 8

Weakness of palatal elevators

Superior pharyngeal constrictor and tensor veli palatini

Question 9

What is the differences between nasogastric tubes and percutaneous endoscopic gastrostomy?

Answer 9

NG tube: insertion relatively easy, negligible mortality, temporary

PEG tube: less irritating, more cosmetically acceptable, long term

Purpose: maintain nutrition, does not decrease the risk of aspiration pneumonia

Question 10

What are the dysphagia risk factors with stroke?

Answer 10

Type of stroke

Bilateral Brainstem: 100%

Unilateral Brainstem: 70%

Bilateral Hemispheric: 50%

Unilateral Hemispheric: 30%

Question 11

What types of swallowing problems are associated with solids or liquids?

Answer 11

Worse with solids: difficulty in clearing pharynx

Worse with liquids: nasal reflux and laryngeal penetration (aspiration)

Question 12

What is delayed initiation of swallowing caused by?

Answer 12

Weakness of the tongue and numbness of the posterior palate and pharynx

Question 13

What characterizes an abnormal bedside swallowing test?

Answer 13

Cough within 1 minute or wet hoarse quality to voice

Question 14

What causes difficulty clearing the pharynx.

Answer 14

Weakness of laryngeal elevators and pharyngeal constrictors

Question 15

What are the signs associated with risk of dysphagia?

Answer 15

Abnormal gag

Abnormal cough

Dysarthria

Large stroke: drowsiness, language problems, gaze paresis, facial weakness

Question 16

What causes aspiration during swallowing.

Answer 16

Weakness of pharyngeal and laryngeal muscles

Numbness of the pharynx

Question 17

What is the difference between chin up and chin tuck during swallowing?

Answer 17

Chin up: facilitates oral transit (uses gravity)

• Numbness in posterior palate
• Weakness in tongue muscle

Chin tuck: narrows pharyngeal space, facilitates laryngeal excursion, increases pharyngeal transit

Question 18

What is the role of the reticular formation in swallowing?

Answer 18

It coordinates the actions of the other cranial nerves.

Question 19

What are the complications of disordered swallowing?

Answer 19

Difficulty initiating

Closing the nasopharynx (nasal reflux)

Closing larynx (aspiration)

Clearing Pharynx

Leading to poor nutrition and pneumonia

Question 20

What are the diagnostic tools for dysphagia?

Answer 20

Patient self report

• Problem with fluid suggests neurological problem
• Problem with solid suggests mechanical problem

Cranial nerve exam

Modified Barium Swallow (MBS) - done by speech path or radiology

Bedside swallowing testing (3 oz. water swallow test)