Etiology
Muscle deconditioning disorders result from underuse of the voice. Bowing is the most obvious visual manifestation of muscle atrophy related to underuse and the term vocal fold bowing is commonly used. While bowing may be typically found in the elderly (and labeled presbyphonia - literally the aging voice), it also occurs in younger people who do not vocalize significantly. These vocal underdoers often rate their talkativeness as a 4 or less on the 7 point talkativeness scale.
Two principal manifestations of atrophy of the vocal folds are a soft edged voice and vocal fatigue. It is the vocal underdoer who suffers from the vocal fatigue syndrome. This is typically a person who rates their talkativeness low on the scale and has a job to match. They then receive a promotion or change to a job that now requires a lot of talking. They are not prepared for this and suffer the consequences in the form of laryngeal achiness with talking.
Neurologic diseases such as Parkinsonism that reduce the drive to speak and reduce the drive to speak loudly may lead to laryngeal muscle atrophy.
The adage use it or lose it applys to the muscles used for speaking.
Diagnosis
History
Typical complaints
- unhappy if job requires a lot of talking
- I ache after talking
- I hate to talk at home
- tightness, choking, discomfort in voice box after talking
- anterior neck awareness
- voice best in morning
- fades in afternoon to a foggy or fuzzy quality
- cannot be heard in noisy places
- lack of endurance
Character of an underdoer
- tend to find quiet jobs
- typical jobs might be accounting, computer programming
- avoids noisy places
- if they have a vocally demanding job, their complaint will be directed at laryngeal discomfort
- If elderly and living alone - at risk for muscle atrophy
- common condition in Parkinsons disease
- talkativeness scale: 1-3, sometimes 4
Vocal capabilities
- Reading voice
- breathy at low pitch
- it may be obligate falsetto to maintain an adequate volume. This is your typical elderly male voice that is starting to sound a bit feminine
- Pitch range
- obligate falsetto
- Limitations will be present at the lower end of the pitch range because muscular disorders increase the laxity of the fold and the tensioning of the cricothyroids to produce a high pitch may be essential to even getting the vocal folds to vibrate. As lower pitch is attempted, the vocal folds becomes looser and further apart until they fail to vibrate.
- Sustained pitch
- In differentiating from neurogenic disorders there should be no vocal catches or spasms characteristic of spasmodic dysphonia.
- Patients with an extrapyramidal weak voice should have a regularly irregular voice.
- Yelling voice
- becomes pressed
- this test should help differentiate bowing from neurogenic disorders. Vocal underdoers with bowed vocal folds should be able to increase their volume with increasing coaching to increase their effort.
- shortened duration when performed at a comfortable volume
Laryngeal Exam
- Rigid videolaryngeal exam
- bowed glottic opening
- the prephonatory instant (just prior to blurring of the folds) will reveal an open glottis at multiple pitches
- Flexible laryngeal exam
- Atrophy is prominent from a posterior glottic vantage point looking toward the anterior commisure
- Laryngeal ventricle is capacious
- subglottic conus may be flattened or concave
- in severe cases the vocal ligament may be the most prominent structure of the vocal fold
- Stroboscopic exam
- ratio of open phase to closed phase - increased
- there may never be a completely closed instant
If the history and vocal capabilities point to a mucosal lesion, look for it. Even very small lesions can be significant, particularly if the patient is a singer and needs their high range for soft singing.
Treatment
Medical
Behavioral
Voice building exercises
- In its simplest form, this could amount to 10 minutes twice a day reading aloud as if projecting the voice to an audience.
- With this amount of dedication, there should be some improvement within three weeks
Speech Therapy
- Posture and breath support may increse the energy imparted to the vocal folds.
- Coaching may be essential to reset the feedback loop that seems to be present in Parkinsons hypophonia. Otherwise the patients fear that they are yelling prevents them from vocally excercising appropriately.
Surgical
If there is insufficient improvement with behavioral modification, bilateral vocal implants may be considered.
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