Fundamental Questions
What mechanisms alter vocal pitch?
I) Changes in vocal cord length
II) Changes in vocal cord tension
III) Changes in vocal cord mass
IV) Changes in subglottic air pressure
What are the components of speech production?
I) Generator: lungs produce airflow through URTI
II) Phonation: sound production by the vocal cords
III) Resonance: modulation of phonatory output by vibration in the chest, pharynx and head with selective amplification of certain component frequencies
IV) Articulation: formation of consonants & vowels, controlled by lips, tongue, palate, pharynx
o Arise from membranous portion of VCs - typically the anterior 1/3 of TVC
o 90% unilateral and solitary; 10% bilateral or multiple
o Result from phonotrauma
Vocal Cord Polyps
Define:
Supraglottis
Glottis
Subglottis
1) Supraglottis
Larynx structures above the apex of ventricle
Epiglottis, aryepiglottic folds, false vocal folds, superior arytenoids
Respiratory epithelium
2) Glottis
Apex of ventricle to 1 cm inferior to TVF
True vocal folds, anterior commissure
Squamous epithelium
3) Subglottis
From inferior aspect of true vocal fold to inferior aspect of cricoid
Respiratory epithelium
Provide at least 2 hypokinetic Neurologic disorders that impact the voice.
§Multiple Sclerosis
§Parkinson’s
§Guillan Barre
§Myasthenia Gravis
§ALS
§Cerebral Vascular Accidents
What is diplophonia?
I) Phonation with two simultaneous fundamental frequencies
II) Divergent travelling wave velocities due to asymmetric stiffness
o Typically unilateral
o Histology: pyogenic granuloma covered thickened, squamous epithelium
o Often associated with GERD
Contact Granuloma or Intubation Granuloma
Bonus: In a non-intubated patient - cause?
o Bilateral, flat, translucent, soft mucosal protuberances
o Arise from vibrating part of the VC
o Typically from functional overuse
Vocal Cord Nodules
Primarily Boys and women
Children with clefts
23.2% of hoarse kids
25% of hoarse singers
Cause of hoarseness in ~43% of female teachers
Boundaries of the Pre-epiglottic and paraglottic spaces
Paraglottic Space
o Lateral: thyroid cartilage (anterior) and mucosa over medial wall of pyriform fossa (posteriorly)
o Superior: quadrangular membrane
(AKA preepiglottic space)
o Inferior: conus elasticus
Preepiglottic Space
Boundaries
o superior: hyoepiglottic ligament
o anterior: thyrohyoid membrane, thyroid cartilage
o inferior: thyroepiglottic ligament
o posterior: epiglottis, quadrangular membrane
Two spaces freely communicate with each other
Provide 3 Hyperkinetic Neurologic disorders
§ADDuctor Spasmodic Dysphonia
§ABDuctor Spasmodic Dysphonia
§Muscle Tension Dysphonia
§Functional Aphonia
§Paradoxical Vocal Fold Motion Disorder (Episodic Laryngospasm or Inducable Laryngeal Obstruction)
Evaluated criteria on laryngovideostroboscopy (remember SAPMuC)
I) Symmetry
II) Amplitude
III) Periodicity
IV) Mucosal wave
V) Closure
VI) Bonus: What is the Fundamental frequency?
VII) What is a harmonic?
Function of the lateral thyroarytenoid?
Lateral Thyroarytenoid - slightly ADducts, also shortens and slackens VC
lowers pitch
Bonus: What does the vocalis do?
Define 3:
Coherence -
Collimited -
Fluence -
Absorption -
Scatter -
Reflection -
Transmission -
Coherence - peaks/troughs of waves occur in phase together (spatially and temporally)
Collimited - parallel rays of energy
Fluence - power density x time (total amount of laser energy per unit area of exposed target tissue)
Absorption - energy taken up by tissue, converted to heat
Scatter - the energy is scattered into the tissue (larger amount of tissue, decreased depth)
Reflection - bounced off tissue
Transmission - shot through the tissue
What makes up the vocal ligament?
Intermediate and deep lamina propria
Intermediate Lamina Propria = Longitudinal elastin fibers
Deep Lamina Propria = Organized collagen fibers, Some fibroblasts, more stiff allowing for vocal fold cover fluidity
Bonus: What is Reinke's Space?
DIRECT
-voice hygiene
-exercises, breathing
-manual circumlaryngeal techniques
INDIRECT
-relaxation, counseling
-tx anxiety, depression
Cochrane review (2007)
-included SIX RCT
-effective in improving vocal function
What is voice therapy?
What are Jitter and Shimmer?
Method to quantitate vocal harshness.
(1) Jitter: cycle to cycle frequency perturbation (jitter bug on radio frequency)
(2) Shimmer: cycle to cycle amplitude perturbation (sham)
(3) Signal to Noise Ratio
Give three potential TEP failure causes.
Prosthesis valve failure - replace/ treat fungal infection
Prosthesis too long/pistoning - replace/resize
Pharyngoesophageal spasm - contraction of persistent cricopharyngeal muscles when midesophagus is distended with air
Treat with: Injections of pharyngeal muscles with Botox, cricopharyngeal and constrictor myotomies, or pharyngeal neurectomies
o Expansion of the loose subepithelial, mobile layer in the VCs
o Most important factor = smoking
o Typically both VCs affected
Reinke's Edema
5 layers of vocal fold
o Mucosal layer (pseudostratified nonkeratinizing squamous epithelium)
o Lamina propria (3)
§ Superficial layer (Reinke’s space): fibroblasts, scant elastic and collagen fibers
§ Intermediate layer: mainly elastic fibers, few fibroblasts
§ Deep layer: collagenous fibers
o Vocalis muscle
Primarily Females
Risks include voice abuse
Pathophysiology = Vibratory microtrauma and Capillary angiogenesis + Mucosal swelling
Commonly seen to cause decreased singing endurance, delayed phonatory onset, loss of high soft singing and increased effort
Usually unilateral
Capillary Ectasia
Capillary fragility may place women at greater risk of forming recurrent hemorrhage or a hemorrhagic polyp.
What is the MPT?
Maximum phonation time: maximum period a subject can maintain audible phonation of a vowel at comfortable pitch and loudness (men 22-34 sec, women 16-25 sec)
A test for SLN paralysis (cricothyroid paralysis); normally, anterior thyroid cartilage pressure decreases pitch, lateral thyroid cartilage pressure increases pitch; with cricothyroid paralysis this reverses
What is a Guttman’s test?
o Diffuse swelling of the epiglottis and AE folds
§ May improve with steroids
o Swelling firm and tends to be limited to the supraglottic space
o Histology: noncaseating granulomas
Sarcoidosis
o Turban sign
Bonus: Where do RA, Sarcoid, TB, Wegner's and Amyloid impact the Larynx?
An anastamosis found in 87% of cadaver studies between the internal branch of SLN with sensory branches from the RLN.
Galen's Anastamosis
In other studies: 21% had at least two anasatmosis and 79% had 3 or more connections. Laryngoscope 1999
Epithelium lined pocket
Lips parallel edge of TVC
Glottic Sulcus
Type I– epithelial invagination limited to superficial lamina propria; minimal impact on voice
Type II-- sulcus vergetrue– extends fold length with increased vocal disturbances
Type III– invagination that penetrates the vocal ligament or vocalis muscle