Pathology of the Larynx Flashcards
What is the cardinal symptom of laryngeal disease?
Hoarseness of voice
What are the benign causes of voice hoarseness?
Infection
Inflammation
Vocal cord nodules
What must always be done when someone presents with hoarseness of voice?
Presence must be regarded as an ominous sign requiring careful investigations
Why must the presence of hoarseness be considered as an ominous sign?
Given the extent of a serious pathology that can cause hoarseness of loss of voice
What are the more concerning pathologies causing hoarseness of voice?
Damage to nerve supplying larynx
Pathology directly involving tissues of larynx
What can cause damage to nerves supplying larynx?
Either surgery or disease involving structures close to larynx
What determines the effects of damage to nerves supplying the vocal cords?
Degree of damage (complete or partial)
Wether this is unilateral or bilateral
What are the potential consequences of damage to nerves supplying the vocal cords?
Phonation
Breathing
Give an example of when damage to nerves supplying vocal cords might not be too severe?
Damage to superior laryngeal nerve (or its external branch) may only cause some weakness of phonation, particularly higher pitch
What does unilateral complete injury to the recurrent laryngeal nerve cause?
Vocal cord on affected side to become immobile
What could cause unilateral complete injury to recurrent laryngeal nerve?
Division of the nerve
What position does the vocal cord take up in unilateral complete injury to the recurrent laryngeal nerve?
Neutral (or paramedian) position between abduction and adduction
What is the result of the opposite cord being unaffected in unilateral complete injury to the recurrent laryngeal nerve?
It can compensate quite well
What are the consequences of unilateral complete injury to the recurrent laryngeal nerve?
May be some hoarseness and a weaker cough
Passage of air through glottis will be minimally affected, if at all - difficulties breathing not usually reported
What happens if there is bilateral complete injury to recurrent laryngeal nerves?
Both vocal cords assume paramedial position, and the rima glottidis becomes extremely narrow
What is the result of the narrowing of the rima glottidis in bilateral complete injury to recurrent laryngeal nerve?
Affects patients ability to speak
Position of vocal cords obstructs movement of air into and out of trachea, and so patients present with difficulty breathing and sometimes stridor
What presents a greater threat, lesions that progressively involve both nerves/only bruise the nerves, or complete division of nerves?
Could be lesions that progressively involve both nerves, or only bruise the nerves
Why do lesions that progressively involve both nerves, or only bruise the nerves, present greater threat?
Semon postulated reason may be due to that in partial injury to recurrent laryngeal nerve, the abductor muscles are paralysed before the adductors, therefore in gradual lesions, the vocal cords are adducted together, causing significant obstruction to air moving into and out of trachea.
It has since become apparent that it is much more complex than this
What should happen if the two vocal cords significantly impede air flow?
An emergency tracheostomy may be necessary to allow the patient to breath
What route does the left recurrent laryngeal nerve take?
It loops around the arch of the aorta before ascending back up in a groove between oesophagus and trachea
What is result of the recurrent laryngeal nerves having a long course in the neck?
They are susceptible to disease and injury that affects the neck and upper chest
Give two examples of conditions that may affect the left recurrent laryngeal nerve
Aortic arch aneurysms
Left apical lung tumours
How may carcinomas of the larynx present?
Hoaseness and/or airway problems
What is often the earliest presenting sign of lesions affecting the vocal cords?
Horaseness of voice
When is laryngeal cancer prognosis favourable?
If the laryngeal cancer is small and involves glottis, and is caught early
Why is laryngeal cancer prognosis favourable when it involves the glottis?
This area has very minimal lymphatic drainage, so less likely to spread
Where does laryngeal cancer have a poorer prognosis?
In the supra- and infraglottic regions
Why does cancer in the supra- and infraglottic regions have a poorer prognosis?
They drain to neck nodes and paratracheal nodes respectively
