Voice Resonance Week 4: Laryngoscopy/Stroboscopy/EGG

Rigid Laryngoscopy

Provides the clearest magnified view of the larynx; images are usually recorded on video.

How is a rigid laryngoscopy viewed?

Through an endoscope that is passed through the patients mouth while the patients tongue is held by the examiner.

What do you get from the rigid laryngoscopy?

Only a phonatory sample, but the image is a lot clearer.

Flexible Laryngoscopy

Viewing the larynx in action; you get a more functional view of the larynx.

How is the flexible laryngoscopy viewed? 

Through a flexible scope that is passed through the patients nose to the back of the throat. 

What does the flexible laryngoscopy provide?

A magnified view of the larynx while the patient produces a sound (singing, speaking, etc).

What do both laryngoscopy have in common?

A strobe light can be used on both of them.

Stroboscopy 

Uses a strobe light to look at a patient’s mucosal wave. 

Step 1 of a Stroboscopy

A microphone is placed on the patient’s neck, which records the sound and measures the frequency.

Step 2 of a Stroboscopy

The strobe light instrument is synchronized with this value and emits flashes of light at a lower frequency.

Step 3 of a Stroboscopy 

When the frequency of the flashes is less than the vibration of the VF, it causes a delay in the portion of each vibratory cycle, and the illusion of slow motion is obtained. 

Step 4 of a Stroboscopy

This allows the viewing of the VF vibration properties during the different phases of the VF vibration cycle (mucosal wave).

What do you look for during a laryngoscopy/stroboscopy?

-Symmetry

-Structure (nodules, redness, puffiness)

-Mucosal wave characteristics (phase/time)

-Periodicity

-Amplitude

-Glottal closure patterns

-Muscle tension

-Movement of the VF/arytenoids

Electroglottography (EGG)

Electrical resistance between 2 electrodes placed around the neck.

Why are the electrodes placed on the skin?

Human tissue is a good conductor of electricity.

What happens when a low voltage current is applied?

The resistance to the passage of electricity is less when the VF are in contact, which gives info about adduction and glottal contact.

What does it mean when the electrodes pass a signal? 

The VF are adducting properly. 

What does it mean when the electrodes do not pass a signal?

The VF are not adducting.

Process of VF Movement

1. Opening Phase

2. Open Phase

3. Closing Phase

4. Closed Phase

Open Quotient

EGG measure that equals open phase/time

Closed Quotient

EGG measure that equals closed phase/time

What can the EGG measures tell you?

If there is something wrong with adduction or the mucosal wave.