The aims of this study were to: (1) evaluate the perceptual speech dimensions, speech intelligibility and dysarthria severity of a group of individuals diagnosed with Friedreich’s ataxia (FRDA); (2) determine the presence of subgroups within FRDA dysarthria; (3) investigate the relationship between the speech outcome and the clinical factors of disease progression. The study included 38 individuals (21 female, 17 male) with a confirmed diagnosis of FRDA. A group of 20 non-neurologically impaired individuals served as controls. Perceptual analysis, investigating 30 different dimensions of speech, was conducted on a speech sample obtained from each participant. In addition, the Assessment of Intelligibility of Dysarthria Speech was administered. All FRDA participants presented with dysarthria with severities ranging from mild to moderate. Cluster analysis revealed 3 subgroups, the first presenting with mild dysarthric symptoms, the second with increased velopharyngeal involvement and the third characterized by increased laryngeal dysfunction. Dysarthria severity showed a significant correlation to disease duration but to no other clinical measure. The findings support the notion of subgroups in FRDA dysarthria, representing distinct impairments of the speech mechanism and perhaps reflective of differing evolutions beyond the cerebellum.

This study proposes an automatic method for the detection of pauses and identification of pause types in conversational speech for the purpose of measuring the effects of Friedreich's Ataxia (FRDA) on speech. Speech samples of approximately 3 minutes were recorded from 13 speakers with FRDA and 18 healthy controls. Pauses were measured from the intensity contour and fit with bimodal lognormal distributions using the Expectation-Maximization algorithm in Matlab. In the speakers with FRDA, both modes in the pause distributions had significantly larger means, with disproportionately fewer pauses associated with the first mode. From this preliminary study, it is concluded that distributional analysis of pause duration holds promise as a useful method of measuring the effects of FRDA on functional speech.

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Perceptual speech research in Friedreich ataxia (FRDA) has identified altered nasality as a key component of the dysarthria profile, however the incidence and severity of abnormal nasality remains unknown. Utilizing objective and perceptual methods, data on the relationship between resonance, disease duration, severity, age of onset and genetic profiles were collated. Thirty-seven participants with FRDA and 24 healthy controls provided contemporaneous speech samples for perceptual analysis, and single word samples for acoustic analysis. A subset of participants (eight participants with FRDA and eight controls) underwent nasometry assessment. Twenty-seven participants with FRDA presented with hypernasality and five with hyponasality on perceptual assessment. Acoustic analysis revealed participants with FRDA had greater nasality than controls (p < 0.05). Perceptual ratings of hypernasality correlated with GAA2 repeat length (ρ = 0.37, p = 0.03). Findings highlight the variability of nasality in FRDA, potentially reflecting variation in the neuropathological profile. Data also suggest the influence of genetic profiles on nasality.

Dysphagia in Friedreich ataxia (FRDA) and its impact on quality of life is not adequately understood. The objective of this study was to characterise dysphagia in FRDA and to determine the impact of swallowing dysfunction on activities, participation, and sense of well-being. Thirty-six individuals with a confirmed diagnosis of FRDA were assessed via a clinical bedside examination (CBE), the Royal Brisbane Hospital outcome measure for swallowing, an oral-motor examination and the Australian therapy outcome measures for speech and swallowing (AusTOMS). Data on swallowing function, diet modification and swallowing strategies were collated. Thirty-three (91.67 %) participants exhibited clinical signs of dysphagia according to the CBE, and all participants received ratings indicating swallowing difficulties on at least one other measure. Dysphagia in FRDA is characterised by oral and pharyngeal stage impairment relating to incoordination, weakness and spasticity. A significant positive correlation was found between the severity of impairment, activity, participation and distress/well-being on the AusTOMS, suggesting that swallowing function decreases with overall reductions in quality of life. A significant correlation was found between activity on the AusTOMS and disease duration (r = -0.283, p = 0.012). No significant correlations were found between dysphagia severity and GAA repeat length, age of onset or disease severity. Participants employing diet modification and swallowing strategies demonstrated higher dysphagia severity, activity limitations and participation restrictions. These data advocate a holistic approach to dysphagia management in FRDA. Early detection of swallowing impairment and consideration of the potential impact dysphagia has on quality of life should be key aspects in disease management.