The relevance of stroboscopy in functional dysphonias(1).

OBJECTIVES

Functional dysphonias are disorders of the voice characterized by sound and efficiency disturbances of the voice without any organic changes of structures being detectable. At present, functional dysphonias are generally subclassified into hyper- and hypofunctional dysphonias in clinical practice.

STUDY DESIGN

The study was designed for a critical evaluation of the relevance of stroboscopy to the diagnostics and classification of functional dysphonias.

METHODS

45 patients were examined (27 hyperfunctional, 15 hypofunctional and 3 mixed type) using videostroboscopy. Several stroboscopic parameters were taken into consideration. Three geometrical and three time-dependent parameters were first analyzed in a uni- and multidimensional way, then cluster analyses were performed.

RESULTS

We could not confirm the clinical subdivision into hyper- and hypofunctional dysphonias as based on anamnestic data, perceptual evaluation of voice sound, voice profile measurements and videostroboscopy. Quantitative measurements of selected parameters did not correlate with qualitative subjective stroboscopic assessment. In addition to this, it was not possible to identify separate clusters of stroboscopic findings.

CONCLUSIONS

The results do not deny the clinical relevance of stroboscopy to the diagnostics of functional dysphonias as a very useful tool to exclude organic lesions. However, a reliable subclassification into different types of functional dysphonias was not possible.