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pathophysiology of VFP, it has proved particularly disap-

pointing as a prognostic tool, at best only partially

helpful in informing treatment of individual patients.

This study was undertaken with the understanding

that any re-examination of the laryngoscopy of VFP

must be carried out using a commonly agreed-upon

array of findings. The evolving discussion about vocal

fold paresis, or partial paralysis of the vocal fold, reveals

clearly that lack of consensus regarding clinical findings

prevents conclusions regarding diagnosis, much less

prognosis, treatment, and outcomes.

No definitions of the terms used were provided to

the reviewers for the simple reason that no such defini-

tions exist. The terms used in this study have entered

the literature informally, and the medical discourse has

generally assumed that a broad and consistent under-

standing of these descriptors exists. This study is a

formal testing of that assumption.

This investigation reveals that the evaluation of lar-

yngoscopic appearance of VFP remains a personal and

individual activity. As demonstrated by multiple correla-

tion calculations, most evaluators were relatively

consistent in their own evaluations across the entire

range of features presented. These results were roughly

equivalent to those of Rosen, who found that two thirds

of voice professionals reviewing stroboscopic exams had

intra-rater reliability scores less than 0.80.

Thus, it is

possible that individual practitioners might use laryngo-

scopic features to analyze cases for diagnosis, as for

example to identify degree of denervation, distribution of

involvement across laryngeal muscles, and for selection

and timing of treatment in a reasonably reliable manner.

It remains to be proven, of course, that pathophysiologic

aspects such as degree and distribution of neural com-

promise indeed have consistent laryngoscopic correlates.

Incidentally, this study does not demonstrate whether

individual observations across multiple examinations are

reliable, or if changes over time in the same case can be

consistently identified.

On the other hand, inter-rater variability

revealed considerable lack of consensus regarding all

aspects but salivary pooling, bowing, and a simplified

rating of the degree of glottic insufficiency. Our study

might even have been biased in favor of greater inter-

rater agreement by the inclusion of the audio track in

the video samples sent to reviewers. Such additional

information might provide clues to blinded reviewers

who are ultimately being studied for their video per-

ceptual analysis alone. Future work in this area will

require removal of all audio from samples sent to

reviewers. Not only is this lack of agreement discour-

aging for the development of a unified rating system

for this disorder, it also calls into question existing

assumptions in the literature about consensus in the

rating of features such as posterior gap (an important

factor in the selection of patients for arytenoid adduc-

tion surgery), vocal fold height (hypothesized to be

relevant to rehabilitation technique), and other fea-

tures referred to in the discussion of the evaluation of

unsatisfactory results of medialization.

7,15–17

General-

izations from study to study might be compromised by

patient populations that are not comparable or equiva-

lent. Also, treatment recommendations or descriptions

of outcome based on laryngoscopic features are likely

to be of limited utility. The prospects for agreement

on vocal fold paresis, where clinical variability would

be expected to be greater than in VFP at the same

time that the degree of abnormality would be less,

appear to be extremely poor.

Based on our results, degree of glottic insufficiency,

vocal fold bowing, salivary pooling, and perhaps to a

lesser extent volitional adduction, vocal fold tone, and

vocal fold atrophy appear to be the best candidates for

development into a standardized system of rating VFP.

A rating or classification system for VFP based on only

the three most consistently appreciated criteria might

not be discriminating enough to be useful in diagnosis or

treatment. We hypothesize that more formal develop-

ment of rating categories, including explicit definitions

and examples, would generate greater inter-rater agree-

ment, for the terms and concepts evaluated in this

investigation have received relatively little formal atten-

tion despite commonplace clinical use. We intend to

explore this further before trialing an integrated rating

system. At the same time, we recognize the possibility

that individual variation in laryngeal anatomy and pos-

sibly in innervation, and the heterogeneity of

neuropathic dysfunction might yet defeat such an effort.

CONCLUSION

However, although individuals are often consistent

in their own evaluation of laryngoscopic features of VFP,

little consensus appears to exist among physicians

regarding these same findings. This raises the possibility

that many assumptions about the significance of lar-

yngoscopic features might not be reliable. This is an

obvious challenge to arriving at a unified understanding

of the laryngoscopic appearance of the disorder and will

need to be addressed.

Results suggest that degree of glottic insufficiency,

vocal fold bowing, and salivary pooling appear to be lar-

yngoscopic features in cases of VFP with the highest

inter-rater reliability. With further investigation and

standardization, these might form a basis for the devel-

opment of a clinically useful rating scheme.

Acknowledgments

We gratefully acknowledge the participation of the

following as raters or consultants in this study: Drs. Linda

Gerber, Gregory Postma, Michael Johns, Edward Dam-

rose, Marshall Smith, Tanya Meyer, Gaelyn Garrett, Rich-

ard Kelly, Mark Courey, Seth Dailey, Ajay Chitkara, Sid

Khosla, Pieter Noordzij, Libby Smith, Phillip Song, James

Thomas, Albert Merati, Andrew McWhorter, Joel Blumin,

Michiel Bove, and Milan Amin.

BIBLIOGRAPHY

1. Semon F. Clinical remarks on the proclivity of the abductor

fibres of the the recurrent laryngeal nerve to become

Laryngoscope 120: July 2010

Rosow and Sulica: Laryngoscopy of Vocal Fold Paralysis