Physiological features of dysarthria in Friedreich's ataxia

Abstract

Due to the paucity of literature concerning the motor speech impairment in persons with Friedreich's ataxia (FA), the aim of this study was to investigate the perceptual and physiological features of dysarthria in a 30-year-old male with FA, 22 years post diagnosis. The four speech subsystems were comprehensively evaluated using physiological measures of respiratory (Respitrace), laryngeal (Laryngograph, Aerophone II), velopharyngeal (Nasometer) and articulatory (lip and tongue pressure transduction systems) function. Perceptual speech evaluations included the Frenchay Dysarthria Assessment, the Assessment of Intelligibility of Dysarthric Speech and a perceptual analysis of a speech sample. The findings were compared with those of non-neurologically impaired controls, matched for age and sex. Results revealed marked impairment in respiratory, velopharyngeal and articulatory function, and mild laryngeal dysfunction. Based on these results the subject was rated as displaying a moderate mixed dysarthria (flaccid/ataxic), with a mild to moderate decrease in overall intelligibility. The results of the assessments will be discussed in relation to the possible effects of FA on motor speech function.