Assessment of Dysarthria

Abstract

A review of literature was performed to understand the current state of assessment of dysarthria and dysarthric speakers globally and in Japan. Assessment of dysarthria is composed of auditory-perceptual impression of speech, and neurological and kinematic characteristics of the speech organs. The traditional approach after a Mayo Clinic study has consisted of patient history, speech features, tests of speech function, and oral mechanism and physical examinations, providing confirmatory signs for neurological diagnosis and identification of dysarthria subtypes. Test batteries for dysarthria are available around the world and in Japan. They are composed of an auditory-perceptual test, speech function tests, and observation of speech organs, but measuring instruments are not employed. Instrumental assessment is classified into three means and targets, such as acoustic analysis of output speech signals, aerodynamic measurement of the vocal tract during speech production, and physiological and kinematic analysis of the speech organs. Both the traditional approach and the test batteries are based on a perceptual scaling method, and thus inherently possess limited quantification. In contrast, instrumental assessment provides quantified data showing physiologic-kinematic changes, but it is not commonly used in clinical practice. Advances in well-defined parameters and cost reduction of the instruments are needed.