Applied Anatomy: Vagus Nerve

Question 1

Injury of the vagus nerve leads to

Answer 1

1. Tachycardia and cardiac arrhythmia
2. Vasovagal attack
3. Injury of pharyngeal branch
4. Injury of laryngeal nerves

Question 2

Vasovagal attack

Answer 2

Reflex of involuntary nervous system due to vagus nerve stimulation ( people seeing blood or subjected to any type of fear) causing bradycardia, hypotension, and dinging attack

Question 3

Injury of pharyngeal branch

Answer 3

Le to dysphagia and soft palate (uvula) deviation to opposite side

Question 4

Injury of external laryngeal nerve

Answer 4

May be cut during clamping and ligation of superior thyroid artery in thyroid lobectomy leading to:
1. Cricothyroid paralysis
2. Vocal cord relaxation
Resulting in:
1. Vocal cords become flaccid and flappy with excess air leakage
2. Voice becomes weak, low pitches, and breathy accompanied by mild hoarseness
Effects occur in bilateral lesion and not noticed in unilateral lesion

Question 5

Injury of reccurent laryngeal nerve: unilateral injury

Answer 5

Common on left side because of long course in neck (thyroid cancer, operation or penetrating neck trauma) and thorax (bronchogenic carcinoma, cardiac surgery, or trauma) leads to:
1. Hoarse breathy voice which may be permanent or less severe with time as opposite cord can hyperadduct and oppose paralysed cord closing glottis during phonation restoring full voice quality

Question 6

Bilateral recurrent laryngeal nerve injury

Answer 6

Can occur by cancer thyroid or during thyroidectomy

Question 7

Partial bilateral injury

Answer 7

Induce abductors paralysis leading to:
1. Vocal cords adduction
2. Dyspnea
3. Stridor
Tracheostomy is life saving

Question 8

Complete bilateral injury

Answer 8

Induce abductors and adductors paralysis putting cords midway between abduction and adduction (cadaveric position) leading to aphonia