Stroboscopic Examination
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Terminology
• Endoscopy: a technique used by
physicians to view internal parts of the
body.
• Laryngoscopy: viewing of the laryngeal
area specifically
• Stroboscopy: “strobos- means whirling”
indicates the use of a particular type of
light during visualization
• Videostroboscopy: makes a permanent
record of the vocal fold patterns for post
hoc analysis
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Endoscopy
• Rigid endoscopes have an
oral insertion
• Flexible endoscopes have a
nasal insertion
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Nasoendoscopy
Flexible
scope
Vocal
Folds
End of
scope
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Rigid Endoscopy
• Head must be tilted up & back for optimal vision.
5
Why Videoendoscopy?
• Primary purposes:
1. To identify the physiologic correlates of
perceived resonance & voice quality for
speech,
2. To document the status of speech
anatomy & physiology during speech
production,
3. To assist educational & clinical discussion
among clinicians, patients, & other
interested individuals.
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• Secondary Purposes:
1. Confirmation of medical
diagnosis,
2. Improving patient
counseling & motivation,
3. Providing biofeedback
therapy.
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Who should do videoendoscopy?
• Medical personnel-physicians (identify disease process
for surgery)
• Nonmedical personnel-SLP (need for specialized knowledge
about speech production &
application clinically)
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Whom is videoendoscopy
appropriate?
• Patients who have:
1) Velopharyngeal and/or laryngeal
disorder that affect speech
production.
i.e. hypernasal patients, cleft palate,
vocal fold pathology etc.
2) Have ability to speak & cooperate9
Mechanics of Videostroboscopy
• Use of intermittent illumination to aid in
the process of observation,
• High-speed camera photography motion
picture,
• Constant light to record images in frames
on film & sequentially projected,
• On-line visualization of movement
• Intervals between flashes can be
regulated
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Flash 1
image 1
Flash 2
image 2
Flash 3
image 3
Flash 4
image 4
composite
image
composite
image
• Top: light pulses are regular & produced at the same
frequency (still); Bottom: pulses regular but differ 1.5
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Hz from the frequency of vibration (motion)
A
B
(A) Synchronized flash intervals, illumination
occurring at same point of each cycle,
motionless
(B) Flash intervals occur at faster rate, results
in motion.
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Judgment & Interpretation of
Vibratory Pattern
• Fundamental frequency
• Periodicity
• Amplitude of horizontal
excursion
• Glottal closure
• Symmetry of bilateral movement
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• Mucosal wave
Fundamental frequency
• Fo is read in Hz on the indicator of the
stroboscope,
• Range should be noted during the
evaluation,
• Interpretation: differentiate between
pathological & physiological
1. Stiffer the v.f. tissue, the greater the Fo
- increased activity in the CT
(physiological example)
- scar formation & sulcus vocalis
increase Fo (pathologic example) 14
Periodicity
• Regularity of successive apparent
cycles of vocal fold vibration
• “periodic”- vibration is considered to
be uniform in amplitude and time
• “aperiodic” vibration can vary in
amplitude or frequency
• Periodicity can be regular, irregular
or inconsistent
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Periodicity
• Interpretation:
1. Asymmetry: may be caused by unilateral
recurrent laryngeal nerve paralysis, unilateral
polyp or unilateral carcinoma
2. Interference with homogeneity: may occur by
small cysts or a small carcinoma
3. Flaccidity: abnormally flaccid or pliable
tissue caused by severe RLN paralysis or
edematous lesion
4. Unsteady Tonus: incapability of maintaining
a steady tonus of the laryngeal muscles, seen in
spasmodic dysphonia
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Horizontal & Vertical Movements
• Amplitude of Horizontal Excursion
• Amplitude is the extent of horizontal
excursion of the v.f.’s during vibration:
each fold rated independently
• Ratings are made on a 4 point scale
– small: excursion smaller than normal
– normal: excursion WNL
– great: excursion is greater than normal
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Amplitude
• Interpretation:
1. The shorter the vibrating portion, the smaller
the amplitude (relative lengths of v.f.’s of men
vs. women; or laryngeal webbing)
2. Stiffer the v.f.’s, the smaller the amplitude
(normal falsetto voice; carcinoma, papilloma,
scar, sulcus vocalis, firm nodule, firm polyp)
3. Greater the mass, smaller the amplitude
(carcinoma, granuloma, papilloma, polyp)
4. Greater the Ps, greater the amplitude (loud
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speech)
Schematic of amplitude changes
• Center line
has no visible
movmt.
• first mark
(blue) is
normal
• second
(green), great
movmt.
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Glottal Closure
• Rated as ‘complete” or “incomplete”
• Determined by the extent of v.f.
approximation dung the maximum
closing of the vibratory cycle
• Complete: glottis completely closed for
each cycle
• Incomplete: glottis never closed during
cycle
• Inconsistent: glottis completely closed
during some cycles and incompletely
closed during others
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Glottal Closure
• Interpretation:
1. Impaired adduction of the v.f.’s
(RLN paralysis, ankylosis)
2. Nonlinear edge (nodule, polyp,
papilloma, carcinoma)
3. Stiff edge (no mucosal wave)
(scars, sulcus vocalis)
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A
B
E
F
C
G
D
H
(A) complete closure, (B) spindle-shaped gap
along entire edge, (C) spindle-shaped gap at
middle, (D) hourglass-shaped gap, (E) gap by
unilateral oval mass, (F) gap with irregular
shape, (G) gap at post. glottis, (H) gap along
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entire length
Symmetry of bilateral movement
• Degree to which the 2 vocal folds provide
mirror images of one another during
vibration,
• Timing and extent of excursion during
vibration, if same then symmetrical, if not
asymmetrical,
• Describe asymmetry (i.e. excursion of right
fold has a greater amplitude etc.)
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Mucosal Wave
• Mucosal waves can be described as:
1. Absent: no observable traveling
wave
2. Small: wave is present, but less
marked than normal
3. Normal: clearly observable traveling
mucosal wave
4. Great: extraordinarily marked wave
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Mucosal Wave
• Interpretation:
1. Stiffer the mucosa, less marked the wave
(falsetto, scars, papillomas, cysts,
fiberoptic nodules)
2. Partially stiff mucosa (wave stops
traveling at stiff portion, sulcus vocalis,
localized scar, small cyst)
3. Tight or loose glottal closure (decrease in
wave, hyper- or hypokinetic phonation) 25
Readings
• If you would like extra readings on
stroboscopy you may want to refer to:
Hirano & Bless, Videostroboscopic Examination
of the larynx, Singular Publishing, 1993.
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Benign Laryngeal Pathologies
• Category 2:
– Voice difficulties due to abnormal growths & lesions, tissue
degeneration, joint immobility, or fractures caused by:
• intubation, gastro-esophageal reflux, chronic cigarette smoking
inhalation, presbylaryngis, thyroid gland disease, upper respiratory
infection, cervical rheumatoid arthritis, & external laryngeal
trauma
• Granulomas
– Webs
– Pacydermia laryngis
– Hyperplastic-leukoplakic lesions
– Cricoarytenoid joint fixation
– Bowing
– Infectious laryngitis
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Granuloma
• Primary voice symptom: hoarsness
• Description: mass lesions on the vocal
process of the arytenoid cartilage in post.
larynx, unless large does not effect the
vibrating portion of the vocal folds,
vascular lesion from tissue irritation in
post. larynx
• Etiology: persistent misuse (contact),
intubation during surgery,
gastroesophageal reflux
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Granuloma
• Acoustic Signs:
– Greater than normal perturbation (jitter &
shimmer)
• Measurable Physiological Signs:
– Normal airflow rates
• Observable Physiological Signs:
– Irregularly shaped masses of tissue either at the
site of the vocal processes of the arytenoids or
elsewhere on the vocal folds
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Treatment
• Antireflux regime (raising head
off bed, not eating before retiring,
drugs such as propulsin)
• Surgery
• Support by SLP during
management process for lesions
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Case 33 (CD 1, Track 33)
• History:
– 65 year old male
– Significant smoking history
– 4 months of mild hoarseness & sore throat
– Frequent heartburn symptoms, acid
regurgitation & chronic throat clearing
– Enjoys spicy foods, teas, colas, late night
snacks
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Case 33
• Examination Findings:
– Mildly hoarse-harsh
– Videostroboscopy• 2 large, smooth, rounded, pearl-colored masses near
vocal process or arytenoids
• Interlock during phonation
• Inhibit complete posterior glottic closure
– Diagnosis: bilateral vocal process granulomas
secondary to chronic reflux laryngitis
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Granuloma (Case 33): Pretreatment
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Case 33
• Treatment:
– Dietary & lifestyle changes to decrease GER
– Prescribed Prilosec (Omeprazole), 20 mg orally
every 12 hours to inhibit gastric acid secretion
• Treatment Results:
– Repeat video 4 weeks after antireflux therapy
– Subjective voice improvement
– Reflux symptoms disappeared
– Near complete resolution of right granuloma
– Left not changed, but more sessile & rounded
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Granuloma (Case 33): Post-treatment
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Discussion
• Chronic gastroesophageal reflux may manifest
as laryngeal disease
• May describe heartburn symptoms
• 34% will present with isolated laryngeal
symptoms
– excess “phlegm”
– chronic throat clearing
– acid regurgitation
– dysphagia
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Papilloma
• Primary voice symptom: hoarseness, low
pitch
• Description: multiple wart-like lesions,
develop in epithelium & deeper in LP,
vocalis muscle,
• Etiology: caused by viruses, may spread
to larynx, trachea & bronchi, children
(juvenile papilloma) & adults
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Papilloma
• Measurable Physiological Signs:
– Increases stiffness may cause increased pressure
• Observable Physiological Signs:
– Present as whitish cluster of tissue (raspberry)
– Interfere with glottic closure
– Increased stiffness impedes horizontal excursion &
mucosal wave will be absent in the area of lesion
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Case 35 (CD 2; Track 2)
• History:
– 28 year old female
– Presented with long history of recurrent
laryngeal papillomas dating 7 years back
– Six previous procedures for removal of
lesions
– Experiencing dysphonia at time of testing
43
Case 35
• Examination Findings:
– Perceptually- severely breathy hoarse quality with
high pitch breaks occasionally
– Maximum phonation time = 5 seconds
– Acoustic Analysis• Fundamental frequency = 180 Hz
• Jitter %= 3.4
• Shimmer= 0.56 dB
• Harmonic to noise ratio= 1.0 dB
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Case 35
• Examination findings:
– Videostroboscopy:
• Papillomatous tissue distributed over the left true vocal
fold, obscuring fold from direct view
• Right fold not involved
• Glottic chink exists during phonation
• False folds adduct during phonation
– Diagnosis: Recurrent laryngeal papillomas
• Treatment:
• CO2 laser ablation
• Post operative speech therapy
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Papilloma (Case 35): Pretreatment
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Case 35
• Treatment Results:
– CO2laser excision of papillomas
– Returned for speech therapy 2 weeks post surgery
– Perceptual improvement of voice
• Episodic hoarse voice with shrill-like outbursts
• Discussion:
– Cauliflower-like lesions caused by infection with
the human papilloma virus (HPV)
– Benign neoplasm
– Multiple recurrences
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Papilloma (Case 35): Post-treatment
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Blunt or Penetrating Trauma
• Etiology: Strangulation, penetrating
neck wound, blunt trauma resulting
from blow to the neck, fracture of
larynx
– Require medical/surgical treatment
– Voice restoration after surgery
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Inhalation & Thermal Trauma
• Etiology: Inhalation of gases, smoke or steam
– Chemical traceobronchitis
– Hot fumes cause reflex closure of the glottis
(protects trachea & respiratory tracts
• Symptoms: Inflammation, burns, soot around
nose or mouth, respiratory distress, stridor,
wheezing, hoarseness.
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Inhalation Trauma: Anterior Web Formation
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Vocal Fold Bowing: Presbylaryngis
• Occurs when myoelastic tension is
diminished, causing concavity from the
midline of glottis
• Etiology: Aging degenerative changes,
weakness or hyponicity of laryngeal
muscles (RLN damage)
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Vocal Fold Bowing: Presbylaryngis
• Perceptual:
–
–
–
–
Higher than normal pitch (Thinning)
Hoarse-breathy quality
Pitch breaks
Tremor
• Acoustic Findings:
–
–
–
–
Increased jitter % shimmer
Reduced S/N ratio (increased noise)
Elevated subglottal pressure
Increased airflow
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Case 27 (CD 1; Track 27)
• History:
–
–
–
–
–
–
–
–
80 year old female
6 month history of deteriorating voice
16 months later- Thyroidectomy
Chronic hoarseness as chief symptom
Aspiration of thin liquid
Vocal fatigue
Shortness of breath
Left vocal fold paralysis was suspected
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Case 27
• Examination Findings:
– Extrinsic laryngeal region WNL
– Perceptually severely hoarse-breathy with shrill
overlay
– MPT= 7 seconds
• Acoustic Findings:
•
•
•
•
Fundamental frequency= 369 Hz
Jitter %= 1.2
Shimmer= 0.62 dB
Harmonic to noise ratio= 1.5 dB
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Case 27
• Aerodynamic Findings:
– Mean airflow= .496 l/sec
– Subglottal pressure= 10.6 cm H20
– Glottal Resistance= 200 cm/ H20 /lps
• Videostroboscopy:
– Chink across entire length
– Bowed vocal folds (more on left side)
– Both folds were symmetrical & motile
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Vocal Fold Bowing (Case 27): Pretreatment
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Case 27
• Treatment Recommendations:
– Unilateral medialization of the left cord
– Voice therapy to follow
– Isshiki thyroplasty rather than folds injection of
collagen or fat was considered
• Treatment Results:
– Left medialization thyroplasty
– Marked improvement in glottal competency across
midline
– Mild compromise of airway secondary to surgery
– Left fold is edematous
– Right fold remains bowed
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Vocal Fold Bowing (Case 27): Post-treatment
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Vocal Fold Bowing (Case 27): Post-treatmentPhonation
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Discussion
• Bowed vocal folds caused by normal aging &
progressive muscle atrophy
• Exhibited by those with long standing
weakness, paresis, & atrophy of vocal folds
secondary to nerve damage
• Results in spindle shaped glottal chink
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