JC98 (ENT) - Dysphonia and Aphonia Flashcards
Anatomical structures that are affected in dysphonia and dysarthria
Dysphonia:
- True vocal cords
Dysarthria:
Structures for resonance: Nasal cavities, sinuses, pharynx, oral cavity
Structures for articulation: Tongue and teeth, Jaw movement
Mechanical function of true vocal cords
True vocal cords transform kinetic energy of airflow into sound energy
Anatomical layers of vocal cord
Which layer is responsible for voice production
- Epithelium (where sound wave is generated)
- Superficial lamina propria (gel-like, pliability of vocal fold)
- Intermediate lamina propria (like elastic rubber band)
- Deep lamina propria (like fascia)
- Vocalis muscle
Superficial lamina propria (gel-like, pliability of vocal fold)
- transparent, soft layer to support epithelium so that sound wave can be generated on epithelium
- Attachment to deeper layers prevents it from being blown away by airflow
Physiology of the glottic cycle for voice production
- Buildup of supporting air pressure splits the vocal cords apart»_space;> gust of air through vocal cords
- Bernoulli’s Effect of exhaled airstream:
- Narrow gap between cords increase air velocity
- Higher air velocity equals lower air pressure
- Vocal cords are sucked together and close
- Air pressure builds and force open vocal cords again - Continuous exhalation»_space;> cyclical closure of vocal folds
- Airflow is chopped off into cyclical puffs of air, forming sound waves
Define causes of hyper/hyponaslity and ‘hot potato voice’
Hot potato voice - tonsillar hypertrophy, peritonsillar abscess, acute epiglottitis, oropharyngeal obstruction
Hyponasality: inadequate airflow through nose during speech (nose completely blocked)
Hypernasality: excessive airflow through nose during speech (e.g. cleft palate)
Ddx Voice disorders into 3 main categories
- Organic:
- Lung, neurological, and vocal cord lesions - Functional - e.g. muscle tension dysphonia
- Psychogenic - e.g. conversion disorder
(know how to control vocal cord but subconscious problem prevents them from functioning)
Ddx organic causes of voice disorders
Lungs: Poor breathing support
- Poor respiratory condition (e.g. asthma, COPD)
- Poor coordination (normal lungs)
Neurological control:
- Central: poor coordination between lungs and vocal cords (e.g. Parkinsonism)
- Peripheral: RLN palsy, SLN palsy
Local vocal cord lesions:
- Acute laryngitis
- Vocal cord nodules
- Vocal cord polyp
- Reinke’s edema
- Recurrent Respiratory Papillomatosis
- Laryngeal cancer (SCC)
Nerve supple of vocal cord muscles
Recurrent laryngeal nerve palsy (supplies supraglottis, all intrinsic muscles of larynx) – vocal cord palsy
Superior laryngeal nerve palsy (supplies infraglottis, cricothyroid) - can’t sing high pitch
Patient with voice disorder presents with BREATHY VOICE
Ddx
Unilateral vocal cord palsy
Vocal cord nodule
Vocal cord polyp
Patient with voice disorder presents with low pitch, rough voice with exertion on speech
Ddx
Reinke’s edema
Patient with voice disorder presents with rapidly progressive hoarseness and stridor
Ddx
Recurrent Respiratory Papillomatosis
Laryngeal cancer
Vocal cord palsy
- Presentation in unilateral vs bilateral palsy
- Causes
Unilateral: Breathy voice (vocal cords cannot close properly), choking
Bilateral: breathing difficulty, suffocation
Causes:
1) Iatrogenic most common
- HN surgery (along course of RLN)
- Thyroid/ esophagus/ cardiac/ thoracic surgery
2) Recurrent laryngeal nerve lesion
- CA thyroid, esophagus, lung
- Ortner’s syndrome: big left atrium compressing on RLN
3) Brainstem lesion (RLN = branch of vagus)
4) Idiopathic (usually viral infection of external laryngeal nerve = branch of SLN)
5) Arytenocricoid joint lesion (vocal cord cannot move)
- Dislocation after intubation
- Rheumatoid arthritis
- Cancer infiltration from larynx/ hypopharynx
Vocal cord palsy treatment
Unilateral:
- Voice therapy
- Injection laryngoplasty: expand vocal cord, temporary
- Medialization thyroplasty: Place Gore-tex to push paralyzed vocal cord to midline
Bilateral:
- Tracheostomy to protect airway
- Lateralization/ arytenoidectomy
Vocal cord nodules
- Laterality?
- Anatomical location
- S/S
- Cause
- Tx
Anatomy:
- Always bilateral and symmetrical
- At membranous junction of anterior and middle 1/3 of vocal folds
S/S: Breathy voice (nodules block vocal cord closure)
Cause:
Chronic** vocal trauma»_space; localized edema»_space; fibrosis»_space; nodules
Treatment:
- Speech therapy (improve voice technique to reduce recurrence)
- Excision
Vocal polyp
- Laterality
- S/S
- Cause
- Treatment
Anatomy:
- Unilateral
S/S: Breathy voice
Cause:
- Acute vocal trauma (e.g. yelling)
- Causes capillaries to burst, form hemorrhagic cyst
- Hemoglobin is absorbed, fibrotic polyp remains
Treatment:
- Excision
Reinke’s edema
- Anatomical location
- S/S
- Causes
- Tx
Anatomy:
Fluid collection in Reinke’s space (i.e. superficial lamina propria = 2nd layer, gel-/ jelly- like)
S/S:
Effortful, low pitch, rough voice
(Need strong exhalation effort to build up subglottic air pressure to push heavy VC to move)
Causes:
- Smoking
- Laryngeal reflux (GERD)
- Hypothyroidism
Tx:
Correct underlying causes (stop smoking; PPI for GERD)
Excision (remove jelly from vocal cord)
Recurrent respiratory papillomatosis
- Laterality? Morphology
- S/S
- Cause
- Treatment
Bulky, irregular vocal cord
S/S:
- Rapidly progressive hoarseness, airway obstruction (stridor)
- Malignant transformation and tracheobronchial spread
Cause: HPV subtype 6,11
- Children: In-utero transfer, birth tract contact
- Adult: oral sex
Tx:
- Watchful waiting for spontaneous regression in puberty
- Surgical debulking: Laryngeal debrider or CO2 laser
+/- adjuvant medical therapy (IFN, chemotherapy)
List 3 pre-malignant lesions of the vocal cord
Leukoplakia
Erythroplakia
Recurrent respiratory papillomatosis
Always biopsy to confirm benign or malignant
Laryngeal cancer
- Main histological type
- S/S
- Risk factor
- Treatment
- Main histological type: squamous cell carcinoma
- S/S: Hoarseness, Stridor, Cervical lymphadenopathy
- Risk factor: Smoking
- Treatment
Early: Radiotherapy, Laser excision, Partial laryngectomy
Late: Total laryngectomy, Adjuvant chemo and radiotherapy
Outline history taking questions for voice dysfunction
Onset/ pattern of hoarseness:
Acute vs. chronic
Episodic vs. progressive (CA larynx)
Associated “red flag” symptoms for CA larynx:
Bleeding (in saliva, sputum)
Shortness of breath
Dysphagia
Ddx:
- Known HPV infection
- Recent overuse of voice ]
Social:
Smoking**
Occupation/ vocal demand (recreational singing: church, choir)
Outline P/E and first-line screening for voice dysfunction
PE:
General: any respiratory distress (e.g. bilateral VC palsy) and need for intubation, constitutional S/S for malignancy
Pulmonary exam in full
Head and neck neurological exam for facial movement, tongue movement, jaw movement
Lung function test, imaging for lung diseases
Inspect larynx:
- Indirect laryngoscopy
- Flexible laryngoscopy
- Rigid laryngoscopy
Compare the modalities of laryngoscopy
- approach
- tests performed
- gag reflex
- Pros and Cons
Indirect laryngoscopy
- Press down tongue, see larynx with dental mirror
- Con: elicits gag reflex
Flexible laryngoscopy:
- Trans-nasal
- Pro: Less gag reflex
- Con: Inferior quality of vision (low light)
Rigid laryngoscopy
- Trans-oral
- Stroboscopy test: intermittent light pulsates at fundamental frequency of voice cord vibration, see slow-motion cord movement
- Pro: See subtle vocal cord lesions, best image quality
- Cons: Worst gag reflex
Direct laryngoscopy: Not for clinical use, used for intubation or foreign body removal
Investigations for TNM staging of laryngeal cancer
T - local tumor stage
- Flexible endoscopy (nodule/ polyp/ mass lesion) + biopsy for extent and histological Dx
- Upper panendoscopy (bronchoscopy + esophagoscopy) for Synchronous lesion in upper aerodigestive tract
- CT/MRI neck with contrast for extent and infiltration
N - Regional LN
- USG neck +/- fine needle aspiration cytology
M - distant metastasis
CXR
Blood test
PET (expensive)
Describe reconstruction after total laryngectomy
Remove the whole voice box (cricoid, thyroid cartilage, epiglottis) + neck dissection (cervical lymph node)
Trachea is brought to the skin by permanent tracheostomy (pump air into trachea directly)
After the defect is closed:
Esophagus is connected to the mouth of patient
Air flows out of the neck without going through mouth and nose – no vibrator to convert airflow into sound energy
4 voice rehabilitation methods after total laryngectomy
Electrolarynx
Pneumatic device
Tracheoesophageal speech
Esophageal speech
Electrolarynx
Mechanism
Pros and Cons
Mechanism:
1) Put the vibrator at neck
2) Vibrator generates vibration transmitted through soft tissue of neck into pharynx and oral cavity
3) air inside vibrates and makes sound
Pro: Easy to use
Con: Unnatural robotic voice, inconvenient device, need one hand
Pneumatic device for voice rehabilitation
Mechanism
Pros and Cons
Mechanism:
- Pneumatic device with internal rubber band at tracheostomy
- Air goes through body of pneumatic device»_space; rubber band vibrates»_space; sound energy goes through straw
Pro: Better control of force and speed of breath
Con: Requires greater manual dexterity and coordination, Sputum may be trapped in the device
Tracheoesophageal speech
- Mechanism
- Pros and cons
Mechanism:
Connection between trachea and esophagus (artificial fistula):
- When patient occludes tracheostome, exhaled airflow cannot go out through neck but through fistula into esophagus
- Air going through esophagus vibrates soft tissue wall of esophagus, create sound energy »_space; then articulate through mouth
- a tracheoesophageal valve allows one-way flow
Pro: Good intelligibility, indwelling device is convenient
Cons: Requires greatest manual dexterity and coordination; Saliva, sputum at
posterior aspect require daily cleaning
Esophageal speech
Mechanism
Pros and cons
Mechanism:
Swallow air into esophagus, then release air back (like burps) in a controlled fashion
Cons: Very difficult to learn
