Analysing spectral changes over time to identify articulatory impairments in dysarthria.

Identifying characteristics of articulatory impairment in speech motor disorders is complicated due to the time-consuming nature of kinematic measures. The goal is to explore whether analysing the acoustic signal in terms of total squared changes of Mel-Frequency Cepstral Coefficients (TSC_MFCC) and its pattern over time provides sufficient spectral information to distinguish mild and moderate dysarthric French speakers with Amyotrophic Lateral Sclerosis (ALS) and Parkinson's Disease (PD) from each other and from healthy speakers. Participants produced the vowel-glide sequences /ajajaj/, /ujujuj/, and /wiwiwi/. From the time course of TSC_MFCCs, event-related and global measures were extracted to capture the degree of acoustic change and its variability. In addition, durational measures were obtained. For both mild and moderately impaired PD and ALS speakers, the degree of acoustic change and its variability, averaged over the complete contour, separated PD and ALS speakers from each other and from healthy speakers, especially when producing the sequences /ujujuj/ and /wiwiwi/. Durational measures separated the moderate ALS from healthy and moderate PD speakers. Using the approach on repetitive sequences targeting the lingual and labial articulators to characterize articulatory impairment in speech motor disorders is promising. Findings are discussed against prior findings of articulatory impairment in the populations studied.

[Could speech rate of Wilson's disease dysarthric patient be improved in dual task condition?]. / Le débit de parole du patient wilsonien dysarthrique peut-il être amélioré en condition de double tâche?

INTRODUCTION: Dysarthria is one of the first sign of neurological Wilson's disease and is often characterized by a decreased speech rate. The aim of this study is to determine the abilities of Wilson's disease dysarthric patients to control their speech rate. We examined the impact of dual-tasking on the speech rate of patients as compared to healthy control speakers and in relation with their ability to accelerate speech rate when instructed to do so. METHODS: Twenty-six patients and twenty-six age- and sex-matched healthy controls repeated a sentence during 20 seconds at a comfortable speech rate used as reference. They were then asked to perform the same repetition task but in dual task conditions, in which sentence repetition was done while performing three types of executive grapho-motor tasks. Finally, the ability to control speech rate was tested by asking the speakers to perform the sentence repetition task alone but at a fast rate of speech. RESULTS: A significantly slower speech rate was observed for all patients as compared to controls. In the dual-task conditions, while the speech rate of healthy speakers accelerated significantly, two behaviors are found for the patients. Forty-two percent of the patients reproduced the control pattern with a significant increased in speech rate, while the other group significantly decreased their speech rate. Comparison of the ability of the two groups to intentionally modulate speech rate, when instructed to accelerate, shows that significantly better acceleration was achieved by speakers in the former group compared with the latter. CONCLUSIONS: This study supports the finding that patients with Wilson's disease exhibit an impaired speech rate and also impaired control of speech rate. Indirect assessment of speech rate modulation with the help of a dual-task paradigm has proven to be useful to distinguish patient behaviors. This paradigm could also be envisioned as a tool for rehabilitation.

Corpus callosum abnormalities in Wilson's disease.

INTRODUCTION: Wilson's disease (WD) with neurological presentation is associated with brain lesions classically localised in globus pallidus, putamen, thalamus, mesencephalon, pons and dentate nucleus. Lesions of corpus callosum (CC) have not been studied in a broad population of patients with WD. OBJECTIVE: Evaluation of the frequency of CC lesions in patients with neurological symptoms related to WD. METHOD: The authors included all patients with neurological expression of WD, followed in the French national centre for WD who had a brain MRI between March 2006 and December 2008. The localisation of brain lesions was analysed and the frequency of lesions in CC evaluated. All patients were assessed using the Unified Wilson's Disease Rating Scale. For patients with abnormalities located in CC, a clinical dysconnexion syndrome was investigated. RESULTS: Among 81 patients (45 men, mean age: 34.8 years, from 12 to 74 years) with neurological expression, 42% had white-matter lesions on fluid-attenuated inversion recovery MRI. 23.4% of patients presented CC lesions, limited to the posterior part (splenium). The severity of disability estimated by Unified Wilson's Disease Rating Scale was correlated with the presence of CC lesions on MRI. CONCLUSION: Abnormalities in CC are not unusual (23.4%). Together with lesions of basal ganglia, CC signal changes should suggest the diagnosis of WD.