Vowel Articulation in Patients with Spinocerebellar Ataxia (IJSLPA v1n2a3) - synergy - synergy

Vowel Articulation in Patients with Spinocerebellar Ataxia Pages 63-71

Sabine Skodda1, Uwe Schlegel1, Thomas Klockgether2 and Tanja Schmitz-Hübsch3

1Department of Neurology, Knappschaftskrankenhaus, Ruhr-University of Bochum, In der Schornau 23 – 25, D-44892 Bochum, Germany; 2Department of Neurology / Movement Disorders, Charité – Campus Virchow Klinikum, Augustenburger Platz 1, D-13353 Berlin, Germany; 3Department of Neurology, University Clinic Bonn, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany

DOI: http://dx.doi.org/10.12970/2311-1917.2013.01.02.3

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Abstract: Objective: Abnormalities in vowel articulation have been reported to be a common feature of dysarthria in spinocerebellar ataxia (SCA); however, findings about the degree and pattern of impaired vowel production are inconsistent. Therefore, the aim of the current study was to characterize the pattern of dysfunctional vowel production in patients with SCA by the means of acoustic analysis.

Methods: 31 patients SCA and 32 healthy subjects were tested. Description of vowel articulation was based upon the frequencies of the first and second formant (F1 and F2) of the German vowels /α/, /i/ and /u/ extracted severalfold from defined words within a given reading passage. The mean as well as the coefficient of variance of the respective F1 and F2 values of each single vowel were taken as measures of distinctiveness and steadiness of vowel articulation.

Results: In the SCA group, F1 and F2 values showed increased variability and a specifically restricted range which was particularly seen in the vowel /i/. Furthermore, the dysfunctional pattern differed between male and female patients with SCA.

Conclusions: Measurement of F1 and F2 revealed dysfunctional vowel articulation in SCA – however, with some gender-related specifities – that can be explained by imprecision and reduced range of articulatory movements in ataxic speakers. Therefore, objective measurement of vowel formant frequencies provided additional information to the overall perceptual speech score. According to these preliminary findings, acoustic analysis of speech could be a promising tool for diagnosis, monitoring and detection of therapeutic effects in ataxic dysarthria.

Keywords: Spinocerebellar ataxia, ataxic dysarthria, vowel articulation, formant frequency, acoustic analysis of speech. Read more