Results of a Randomized Clinical Trial of Speech After Early Neurostimulation in Parkinson's Disease.

BACKGROUND: The EARLYSTIM trial demonstrated for Parkinson's disease patients with early motor complications that deep brain stimulation of the subthalamic nucleus (STN-DBS) and best medical treatment (BMT) was superior to BMT alone. OBJECTIVE: This prospective, ancillary study on EARLYSTIM compared changes in blinded speech intelligibility assessment between STN-DBS and BMT over 2 years, and secondary outcomes included non-speech oral movements (maximum phonation time [MPT], oral diadochokinesis), physician- and patient-reported assessments. METHODS: STN-DBS (n = 102) and BMT (n = 99) groups underwent assessments on/off medication at baseline and 24 months (in four conditions: on/off medication, ON/OFF stimulation-for STN-DBS). Words and sentences were randomly presented to blinded listeners, and speech intelligibility rate was measured. Statistical analyses compared changes between the STN-DBS and BMT groups from baseline to 24 months. RESULTS: Over the 2-year period, changes in speech intelligibility and MPT, as well as patient-reported outcomes, were not different between groups, either off or on medication or OFF or ON stimulation, but most outcomes showed a nonsignificant trend toward worsening in both groups. Change in oral diadochokinesis was significantly different between STN-DBS and BMT groups, on medication and OFF STN-DBS, with patients in the STN-DBS group performing slightly worse than patients under BMT only. A signal for clinical worsening with STN-DBS was found for the individual speech item of the Unified Parkinson's Disease Rating Scale, Part III. CONCLUSION: At this early stage of the patients' disease, STN-DBS did not result in a consistent deterioration in blinded speech intelligibility assessment and patient-reported communication, as observed in studies of advanced Parkinson's Disease. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Control of the glottal configuration in ex vivo human models: quantitative anatomy for clinical and experimental practices.

INTRODUCTION: The objective of this paper was to identify the determining factors of the glottal prephonatory configuration from the point of view of the resulting muscular actions (i.e., arytenoids adduction, membranous vocal fold adduction, and tension). MATERIALS AND METHODS: 21 human non-embalmed excised larynges (12 females and 9 males) were studied. Experiment A (11 larynges) studied four conditions of adduction of the vocal folds and arytenoids. Experiment B (10 larynges) studied the effect of cricothyroid approximation on the vocal fold length and the cricothyroid angle. RESULTS: Experiment A: The mean glottal area significantly decreased from 41.2 mm2 mean with no adduction, to 10.2 mm2 mean with arytenoid adduction, to 9.2 mm2 with membranous vocal fold adduction, and down to 1.1 mm2 with the combination of arytenoid and membranous adduction. The effect of the task was statistically significant. Experiment B: The length of vocal folds increased from 13.61 mm median to 14.48 mm median, and the cricothyroid angle decreased of 10.05 median along with cricothyroid approximation. DISCUSSION: The results of experiment A emphasize the sub-division of adductor intrinsic muscles in arytenoids adductors (i.e., LCA and IA), and membranous vocal fold adductor (i.e., TA). The results of experiment B quantify the effect of cricothyroid approximation on the vocal folds length. The implications of these results can be useful in both clinical practice and experimental studies.

Stimulation of the pedunculopontine nucleus area in Parkinson's disease: effects on speech and intelligibility.

Improvement of gait disorders following pedunculopontine nucleus area stimulation in patients with Parkinson's disease has previously been reported and led us to propose this surgical treatment to patients who progressively developed severe gait disorders and freezing despite optimal dopaminergic drug treatment and subthalamic nucleus stimulation. The outcome of our prospective study on the first six patients was somewhat mitigated, as freezing of gait and falls related to freezing were improved by low frequency electrical stimulation of the pedunculopontine nucleus area in some, but not all, patients. Here, we report the speech data prospectively collected in these patients with Parkinson's disease. Indeed, because subthalamic nucleus surgery may lead to speech impairment and a worsening of dysarthria in some patients with Parkinson's disease, we felt it was important to precisely examine any possible modulations of speech for a novel target for deep brain stimulation. Our results suggested a trend towards speech degradation related to the pedunculopontine nucleus area surgery (off stimulation) for aero-phonatory control (maximum phonation time), phono-articulatory coordination (oral diadochokinesis) and speech intelligibility. Possibly, the observed speech degradation may also be linked to the clinical characteristics of the group of patients. The influence of pedunculopontine nucleus area stimulation per se was more complex, depending on the nature of the task: it had a deleterious effect on maximum phonation time and oral diadochokinesis, and mixed effects on speech intelligibility. Whereas levodopa intake and subthalamic nucleus stimulation alone had no and positive effects on speech dimensions, respectively, a negative interaction between the two treatments was observed both before and after pedunculopontine nucleus area surgery. This combination effect did not seem to be modulated by pedunculopontine nucleus area stimulation. Although limited in our group of patients, speech impairment following pedunculopontine nucleus area stimulation is a possible outcome that should be considered before undertaking such surgery. Deleterious effects could be dependent on electrode insertion in this brainstem structure, more than on current spread to nearby structures involved in speech control. The effect of deep brain stimulation on speech in patients with Parkinson's disease remains a challenging and exploratory research area.

[The effect of time-compressed speech on the perception of ataxic dysarthria: a report of two cases]. / Effet de l'accélération artificielle du signal de parole sur la perception des dysarthries cérébelleuses: à propos de deux cas.

AIM: In cerebellar dysarthria, the lack of precision in the articulatory motions leads to a temporal dysregulation with a decreased rate of speech. That is, our hypothesis is that the signal distortions are linked to the slowness of speech and that the acceleration of the rate improves the intelligibility of speech. PATIENTS AND METHOD: Two patients with a cerebellar pathology and an ataxic dysarthria participated in the present study. Speech intelligibility was assessed subjectively by a visual analog scale, and objectively by the constant-stimulus method associated with an identification task of a target phoneme in real time. The SOLA algorithm was used to accelerate the speech stimuli. 144 test sentences were created at 3 speed rates: 48 sentences at 'natural speed' (without compression, VN), 48 sentences at 'intermediate speed' (50% of the maximum rate, VI) and 48 sentences at 'maximum speed' (mean rate of a control group of speakers, VM). The 144 test sentences, in 3 experimental conditions, were distributed over 3 lists, each listener hearing each sentence only once; 8 subjects were assigned to each list. The sentences were presented in random order. A subjective assessment was performed for the whole corpus. The statistical analysis was performed with a mixed logit model for the subjective scores and the reaction time and with a chi2 test for the errors. RESULTS: For each patient, the odds of an improved intelligibility were significantly greater for the VI or VM condition than for the VN condition. The effect tended to be stronger for patient Z. From the VN to the VI condition, the satisfaction rate regarding the intelligibility increased from 78 to 87% for patient B and from 46 to 63% for patient Z (p = 0.03). There were fewer errors for the accelerated speech for patient Z. The acceleration had no effect on the reaction times in the phoneme identification task (F 2,(1,024) = 2.14, p = 0.12). CONCLUSIONS: In 2 cases of ataxic dysarthria, the perceived intelligibility was improved by a temporal acceleration of the speech disorders.

Perceiving nonnative vowels: the effect of context on perception as evidenced by event-related brain potentials.

In 2 experiments, the authors examined the electrophysiological auditory responses of monolingual French listeners to American English vowel contrasts as a function of the surrounding vowel context. The context was determined on the basis of behavioral results (C. Meunier, C. Frenck-Mestre, T. Lelekov-Boissard, & M. Le Besnaris, 2003, 2004). In the 1st experiment, where the vowel /I/ was placed in a context in which it could easily be discriminated from the surrounding vowels (82% /i/ and 3% /ae/), the electrophysiological response to this vowel showed both acoustic and phonemic responses in line with behavioral results. In the 2nd experiment, where the same vowel /i/ was placed in a difficult context (82% /epsilon/ and 3% /ae/), the electrophysiological response of French participants to this vowel revealed a greatly reduced phonemic response, showing assimilation of the vowel to the surrounding context, again in line with behavioral results. The results of a 3rd control experiment with American participants showed both an acoustic and a phonemic response to the vowel /i/ in the difficult context (82% /epsilon/ and 3% /ae/). This pattern demonstrates the fluctuations in perception as a function of context, and hints at a supple system that may be modified through experience.

Phonological training in children with dyslexia using temporally modified speech: a three-step pilot investigation.

Three separate studies were successively carried out to investigate the usefulness of intensively training children with dyslexia with daily exercizes based on the temporal processing theory of dyslexia, according to which these children would be specifically unable to process brief and rapidly changing auditory stimuli. The speech modification, similar for the three studies, was close to that proposed by Merzenich et al. (1996) and Tallal et al. (1996), including both artificial slowing of natural speech stimuli and amplification of brief, unstable portions of the speech signal. In the first study, 12 children, aged 10-12 years, received either such modified speech or normal speech for 1 h a day, 5 days a week, over 5 weeks, and they were assessed on phonological tasks before, during and after training. A significant advantage for the modified speech group was found both in pre-post-training improvement and in day-to-day progression on phonological performance. In a second study, 29 children with dyslexia, aged 5-12, received a similar training, but for only 15 min a day, 7 days a week, over 6 weeks, part at the speech therapist office, part in their own homes. The finding of comparable improvement in a more 'natural' environment and in children over a wider age range indicates both the efficacy and feasibility of the method in usual clinical practice. However, this study also showed that one of four children did not improve as expected, prompting a third study where 23 other children underwent specific tasks presumably exploring various aspects of temporal processing in order to find predictors of training efficacy. A 'temporal order judgement' (TOJ) task was found best correlated with post-training improvement, suggesting that one use this task for selecting the best candidates for temporo-phonological training. Moreover, such correlation provided further argument in favour of the temporal deficit theory of dyslexia, not only by showing a link between a purely temporal task and ultimate phonological performance, but also by demonstrating that TOJ performance itself improves after phonological training. Finally, and taken together, these studies provide further justification for a rational, indication-based temporo-phonological treatment of dyslexia. Possible neural substrates of the relevant mechanisms are discussed in the light of recent experimental and brain-imaging studies.

Temporal processing and phonological impairment in dyslexia: effect of phoneme lengthening on order judgment of two consonants.

The evidence of supporting phonological deficit as a cause of developmental dyslexia has been accumulating rapidly over the past 2 decades, yet the exact mechanisms underlying this deficit remain controversial. Some authors assume that a temporal processing deficit is the source of the phonological disorder observed in dyslexic children. Others maintain that the phonological deficit in dyslexia is basically linguistic, not acoustic, in nature. Three experiments were conducted and tested the impact of the temporal alteration and the impact of complex syllabic structure on consonant order judgments. Thirteen phonological dyslexics (age 10-13) and 10 controls matched for chronologial age were compared on a Temporal Order Judgment (TOJ) task using the succession of two consonants (/p/ /s/) within a cluster. In order to test the possible relevance of the temporal deficit hypothesis, the task also included two additional conditions where either the two stimuli were artificially slowed or two phonological structures were opposed (CCV and CVCV). As expected, the TOJ performance was significantly poorer in dyslexics than in controls. Moreover, in the "slowed speech" condition dyslexics' performance improved to reach the normal controls' level, whereas manipulating the phonological structure complexity provided no significant improvement. Finally dyslexics' performances, especially on the slowed condition, were found correlated with several tests of phonological processing. These results lend support to the general temporal deficit theory of dyslexia.