3 Basic Procedures for SLPs
- VP endoscopy for speech
- Laryngeal stroboscopy
* Designed to evaluate laryngeal VF function - FEES
What is an Invasive Procedure?
One where purposeful/deliberate access to the body is gained via an incision, percutaneous puncture, where instrumentation is used in addition to puncture needle, or instrumentation via a natural orifice. It begin when entry to the body is gained and ends where the instrument is removed, and/or the skin is closed. Invasive procedures are performed by trained healthcare professionals using instruments, which include, but are not limited to, endoscopes, catheters, scalpels, scissors, devices and tubes.
Should SLPs do endoscopy?
- The scope has changed over time however, ASHA Position Statement 2008 said…
* It is the official position of the American Speech-Language-Hearing Association (ASHA) that endoscopy is an imaging procedure included within the scope of practice for speech-language pathologists and described in previously established ASHA documents (ASHA, 1998, 2004c, 2004d, 2004e, 2005a, 2005b, 2007). Speech-language pathologists with specialized training (ASHA, 2002, 2004a) in flexible/nasal endoscopy, rigid/oral endoscopy, and/or stroboscopy use these tools for the purpose of evaluating and treating disorders of speech, voice, resonance, and swallowing function. - Each state has different laws that address endoscopy.
ASHA Code of Ethics and Performing VES
“Individuals shall engage in only those aspects of the professions that are within the scope of their professional practice and competence, considering their level of education, training, and experience.” – ASHA Code of ethics
A Model of Curriculum for VES
i. Rationale performing VES
1. Just because you can do it, doesn’t mean that you should
a. You always need a rationale for why you are doing a procedureii. Normal and disordered anatomy and physiology
a. Education obtained through M.S. degree course work
iii. Endoscopic equipment and technique
1. Endoscope
2. Light source
3. Camera
4. Video storage
5. Defogger
6. Misc (gloves, eye mask, lubricant, mask)
iv. Patient safety – Anesthetics
1. Dosage
2. Anaphylaxis could be an issue
3. Disclosure or consent form
a. Nature of the proposed procedure
b. Reason the procedure is being recommended
c. Benefits of the procedure
d. Risks and complications and frequency
e. Alternatives to the procedure
v. Interpreting and reviewing images
vi. Reporting
a. Summarize and synthesize history, perceptual judgment, acoustic and aerodynamic measures and endoscopy
vii. Performing the procedure
1. Mentoring: one on one
2. Supervised experience
3. Video review
4. Individual practice
The Vocal Folds
Vibration
- Our vocal folds vibrate at a rate that is faster than what can be perceived by the human eye.
- They vibrate 3x faster than a hummingbird.
a. Women: 225 Hz
b. Kids: 265 Hz
c. Men: 135 Hz
The Vocal Folds
VF’s are made up of 5 layers
- Epithelial
- Body (thyroarytenoid muscle – true VF’s)
- Deep lamina propria
- Intermediate of the lamina propria
- Superficial of the lamina propria
What Can we Evaluate with a Continuous Light Source (Halogen)?
i. Vocal fold anatomy
ii. Mucosal color
iii. Gross movement of the structures
Vocal Folds Need What type of Special Imaging?
i. Stroboscopy
1. Used to view the vocal fold vibration by “slowing down” vibration visually
ii. The strobe uses a 30 frames per second rate and the computer will choose specific frames and put them together, so that clinician can see the opening and closing phases of the vocal fold motion.
Who is a Candidate for Videostroboscopy?
ANY patient with VOICE difficulties in whom the DIAGNOSIS is unclear. Should be done for every voice disorder.
Why is Videostroboscopy Valuable aside from Allowing for Observation of Vibratory Characteristics?
i. Can be used to document vocal fold function prior to any treatment.
ii. Evaluate outcomes of various different interventions.
iii. Diagnose etiological causes of voice disorders
iv. Imaging can be compared across different settings
v. Results of therapy can be studied
vi. Can be used during surgical planning and to view surgical results
Examination with Rigid Endoscope
i. Rigid scopes usually have a tip with an angle of 70 or 90 degrees.
1. A 90 degree scope goes straight in and straight down.
2. A 70 degree scope goes in at an angle to allow for a better view of the hypopharynx and causes less gagging because it doesn’t go as far in.
ii. The scope is passed trans orally – which means through the mouth to view the back of the pharynx and larynx
iii. A stethoscope is placed on the patient’s neck to measure the frequency of the VF’s in order for the strobe flashing to be similar to the VF frequency.
1. The flashing is actually ¼ m/s off from the actual frequency.
2. “asynchronized” – but can be set to synchronized.
iv. The computer records 30 frames per second and records images from the same point in vibratory cycle which results in a “still” image.
Vibratory Parameters
Symmetry of Vibration
- Talking about the gross movement of the entire vocal fold
- Refers to the movement of the right and left vocal folds relative to each other.
a. Normally they vibrate as a mirror image of one another (moving laterally and begin to move at the same time and at the same speed) - Differences in mechanical properties of the two vocal folds will result in asymmetric movements.
a. Influenced by position, shape, mass, stiffness, elasticity, and tension of the vocal fold tissue.
Vibratory Parameters
Periodicity of Vibration
- Relative length of the glottal cycle, from open to close.
a. Should be stable from one cycle to another - Using the “synchronized” strobe setting can confirm vibration is periodic.
a. If vibratory cycle is stable from cycle to cycle, then static image will persist even when strobe is set to synchronized.
b. If changes in length of the vibratory cycle are present then there will be movement of the vibratory edge in the synchronized mode. - Phase closure refers to the percentage of time that the vocal fold edges are open and/or closed during a single cycle of vibration.
a. Phase is influenced by mode of phonation (falsetto, modal phonation, glottal fry) and pitch and loudness.
Vibratory Parameters
Amplitude
- Refers to the amount of lateral movement of the vocal folds during vibration.
a. Just looking at the white part. - Normally it increases with increases in subglottic pressure.
a. The white part will lateralize more with increase in subglottic pressure (coughing, loudness). - Amplitude increases as the pitch (frequency) of phonation decreases.
Vibratory Parameters
Glottic Configuration
- Refers to the shape or contour of the glottic opening.
- If there is an opening at the point of maximal closure during the vibratory cycle, then you can mention “contour of glottal margin” or “VF closure pattern”.
Vibratory Parameters
Mucosal Wave
- Refers to the movement of the superficial tissues over the vocal folds as air moves through the glottic.
- It is seen as a traveling wave in the superficial tissues of the top of the vocal folds (medial to lateral)
- During strobe or frame by frame is usually required to adequately assess mucosal wave.
- Mucosal wave can be interrupted by abnormalities of the vocal fold musical covers from things such as scarring, lesions, inflammation or edema.
- If stiffness on one side is observed without a mucosal wave, it could be a sign of cancer within the vocal fold.
Value of Videostroboscopy
i. A study done by Casiano et al found that in patients with voice complaints who had been assumed to have no abnormalities when assessed with indirect laryngoscopy, were diagnosed with a functional voice disorder (misuse). However, when reevaluated using Videostroboscopy the diagnosis changed in 44% of the patients.
1. 20% were diagnosed with vocal fold lesions.
2. 70% of cases where Videostroboscopy resulted in change of diagnosis, a benign tumor was found.
Vocal Fold Polyps (Unilateral)
i. Present with asymmetric vibration
ii. Variable periodicity
iii. Mucosal wave maybe present or absent or appear different one the vocal fold with the polyp compared to the other vocal fold.
iv. Irregular vocal fold margins
v. Glottic closure usually irregular and asymmetric
vi. Stroboscopy and surgical findings correlated 100%.
Bilateral Vocal Fold Nodules
i. Typically demonstrates reduced amplitude of vibration.
ii. Normal periodicity
iii. Mucosal wave present
iv. Hourglass glottic opening at maximal closure.
v. Surgical and stroboscopy findings correlated 100%.
Vocal Fold Cysts
i. Unilateral
ii. Causes asymmetric and aperiodic vibration.
iii. Hourglass glottic closure
iv. Protrusion from the medial vocal fold margin over the cyst
v. Mucosal wave frequently absent over the cyst
vi. Surgical and stroboscopy findings correlated 100% of the time
Limitations of Videostroboscopy
i. Superficial invasive cancer of the larynx cannot be distinguished from a benign process using Videostroboscopy alone.
ii. Videostroboscopy is a two-dimensional process.
iii. Not a reliable way to determine depth of invasion.
iv. Difficult to see medial glottal surfaces.
v. Mucosal bridges are frequently missed.
vi. Cannot be used with all patients.
1. Videostroboscopy requires stable phonation to activate strobe.
2. Severe hoarseness causes rapid changes in phonation frequency.
a. Periodic phonation is required for optimal recording of VF vibration.
3. Several seconds are required to activate the strobe, if a patient cannot phonate for 3-5 seconds at a stable frequency Videostroboscopy may not be possible.
4. Patients with gag reflex
vii. Analysis relies on visual perceptual judgements
1. Susceptible to bias
2. Avoid over diagnosing or seeing pathology that isn’t there.
3. Some vibratory features seen with dysponia can also be seen with healthy/normal cases so it can make it difficult to distinguish.
viii. Rating vibratory characteristics is not reliable.
1. Improved reliability with experience.
ix. We need a standard protocol.
What Are we Looking for When Doing Endoscopy?
i. We are making structural and tissue observations.
- Size and symmetry and tissue health of..
a. Nasopharynx
b. Oropharynx
c. Hypopharynx
d. Laryngeal vestibule - Looking for abnormalities
a. Edema - swelling
b. Erythema - redness of the skin caused by injury or another inflammation-causing condition.
c. Excoriation - To scratch or wear off the skin resulting in an abrasion.
d. Lesions - nodules, polyps and cysts.
e. Masses or mass effects – cancerous/noncancerous
f. Structural deviations (vocal fold deinnervation)
Spaces entered during flexible endoscopy.
i. The nose
ii. Nasopharynx
iii. Oropharynx
iv. Hypopharynx
