Effects of speech therapy and pharmacologic and surgical treatments on voice and speech in Parkinson's disease: a review of the literature

Articulatory Changes in Vowel Production following STN DBS and Levodopa Intake in Parkinson's Disease

Purpose. To investigate the impact of deep brain stimulation of the subthalamic nucleus (STN DBS) and levodopa intake on vowel articulation in dysarthric speakers with Parkinson's disease (PD). Methods. Vowel articulation was assessed in seven Quebec French speakers diagnosed with idiopathic PD who underwent STN DBS. Assessments were conducted on- and off-medication, first prior to surgery and then 1 year later. All recordings were made on-stimulation. Vowel articulation was measured using acoustic vowel space and formant centralization ratio. Results. Compared to the period before surgery, vowel articulation was reduced after surgery when patients were off-medication, while it was better on-medication. The impact of levodopa intake on vowel articulation changed with STN DBS: before surgery, levodopa impaired articulation, while it no longer had a negative effect after surgery. Conclusions. These results indicate that while STN DBS could lead to a direct deterioration in articulation, it may indirectly improve it by reducing the levodopa dose required to manage motor symptoms. These findings suggest that, with respect to speech production, STN DBS and levodopa intake cannot be investigated separately because the two are intrinsically linked. Along with motor symptoms, speech production should be considered when optimizing therapeutic management of patients with PD.

Behavioral treatments for speech in Parkinson's disease: meta-analyses and review of the literature

SUMMARY 

Parkinson's disease (PD) results from neurodegenerative processes leading to alteration of motor functions. Most motor symptoms respond well to pharmacological and neurosurgical treatments, except some axial symptoms such as speech impairment, so-called dysarthria. However, speech therapy is rarely proposed to PD patients. This review aims at evaluating previous research on the effects of speech behavioral therapies in patients with PD. We also performed two meta-analyses focusing on speech loudness and voice pitch. We showed that intensive therapies in PD are the most effective for hypophonia and can lead to some improvement of voice pitch. Although speech therapy is effective in handling PD dysarthria, behavioral speech rehabilitation in PD still needs further validation.

Perceived articulatory precision in patients with Parkinson's disease after deep brain stimulation of subthalamic nucleus and caudal zona incerta

The effect of deep brain stimulation (DBS) of the subthalamic nucleus (STN) and caudal zona incerta (cZi) on speech articulation in patients with Parkinson's disease (PD) was investigated. Read speech samples were collected from nine patients with STN-DBS and 10 with cZi-DBS. The recordings were made pre-operatively and 12 months post-operatively with stimulator on and off (on medication). Blinded, randomised, repeated perceptual assessments were performed on words and isolated fricatives extracted from the recordings to assess (1) overall articulatory quality ratings, (2) frequency of occurrence of misarticulation patterns and (3) fricative production. Statistically significant worsening of articulatory measures on- compared with off-stimulation occurred in the cZi-DBS group, with deteriorated articulatory precision ratings, increased presence of misarticulations (predominately altered realisations of plosives and fricatives) and a reduced accuracy in fricative production. A similar, but not significant, trend was found for the STN-DBS group.

Changes in vowel articulation with subthalamic nucleus deep brain stimulation in dysarthric speakers with Parkinson's disease

Purpose. To investigate changes in vowel articulation with the electrical deep brain stimulation (DBS) of the subthalamic nucleus (STN) in dysarthric speakers with Parkinson's disease (PD). Methods. Eight Quebec-French speakers diagnosed with idiopathic PD who had undergone STN DBS were evaluated ON-stimulation and OFF-stimulation (1 hour after DBS was turned off). Vowel articulation was compared ON-simulation versus OFF-stimulation using acoustic vowel space and formant centralization ratio, calculated with the first (F1) and second formant (F2) of the vowels /i/, /u/, and /a/. The impact of the preceding consonant context on articulation, which represents a measure of coarticulation, was also analyzed as a function of the stimulation state. Results. Maximum vowel articulation increased during ON-stimulation. Analyses also indicate that vowel articulation was modulated by the consonant context but this relationship did not change with STN DBS. Conclusions. Results suggest that STN DBS may improve articulation in dysarthric speakers with PD, in terms of range of movement. Optimization of the electrical parameters for each patient is important and may lead to improvement in speech fine motor control. However, the impact on overall speech intelligibility may still be small. Clinical considerations are discussed and new research avenues are suggested.

Lee Silverman voice treatment versus standard NHS speech and language therapy versus control in Parkinson's disease (PD COMM pilot): study protocol for a randomized controlled trial

Background

Parkinson’s disease is a common movement disorder affecting approximately 127,000 people in the UK, with an estimated two thirds having speech-related problems. Currently there is no preferred approach to speech and language therapy within the NHS and there is little evidence for the effectiveness of standard NHS therapy or Lee Silverman voice treatment. This trial aims to investigate the feasibility and acceptability of randomizing people with Parkinson’s disease-related speech or voice problems to Lee Silverman voice treatment or standard speech and language therapy compared to a no-intervention control.

Methods/Design

The PD COMM pilot is a three arm, assessor-blinded, randomized controlled trial. Randomization will be computer-generated with participants randomized at a ratio of 1:1:1. Participants randomized to intervention arms will be immediately referred to the appropriate speech and language therapist. The target population are patients with a confirmed diagnosis of idiopathic Parkinson’s disease who have problems with their speech or voice. The Lee Silverman voice treatment intervention group will receive the standard regime of 16 sessions between 50 and 60 minutes in length over four weeks, with extra home practice. The standard speech and language therapy intervention group will receive a dose determined by patients’ individual needs, but not exceeding eight weeks of treatment. The control group will receive standard care with no speech and language therapy input for at least six months post-randomization. Outcomes will be assessed at baseline (pre-randomization) and post- randomization at three, six, and 12 months. The outcome measures include patient-reported voice measures, quality of life, resource use, and assessor-rated speech recordings. The recruitment aim is at least 60 participants over 21 months from 11 sites, equating to at least 20 participants in each arm of the trial. This trial is ongoing and recruitment commenced in May 2012.

Discussion

This study will provide information on the feasibility and acceptability of randomizing participants to different speech and language therapies or control/deferred treatment. The findings relating to recruitment, treatment compliance, outcome measures, and effect size will inform a future phase III randomized controlled trial.

Trial registration

International Standard Randomised Controlled Trial Number Register: ISRCTN75223808 registered 22 March 2012.

Early identification and treatment of communication and swallowing deficits in Parkinson disease

Parkinson disease (PD) is a complex, progressive, neurodegenerative disorder that leads to a wide range of deficits including fine and gross sensorimotor impairment, autonomic dysfunction, mood disorders, and cognitive decline. Traditionally, the focus for diagnosis and treatment has been on sensorimotor impairment related to dopamine depletion. It is now widely recognized, however, that PD-related pathology affects multiple central nervous system neurotransmitters and pathways. Communication and swallowing functions can be impaired even in the early stages, significantly affecting health and quality of life. The purpose of this article is to review the literature on early intervention for communication and swallowing impairment in PD. Overarching themes were that (1) studies and interpretation of data from studies in early PD are limited; (2) best therapy practices have not been established, in part due to the heterogeneous nature of PD; and (3) as communication and swallowing problems are pervasive in PD, further treatment research is essential.

Imprecise vowel articulation as a potential early marker of Parkinson's disease: effect of speaking task

The purpose of this study was to analyze vowel articulation across various speaking tasks in a group of 20 early Parkinson's disease (PD) individuals prior to pharmacotherapy. Vowels were extracted from sustained phonation, sentence repetition, reading passage, and monologue. Acoustic analysis was based upon measures of the first (F1) and second (F2) formant of the vowels /a/, /i/, and /u/, vowel space area (VSA), F2i/F2u and vowel articulation index (VAI). Parkinsonian speakers manifested abnormalities in vowel articulation across F2u, VSA, F2i/F2u, and VAI in all speaking tasks except sustained phonation, compared to 15 age-matched healthy control participants. Findings suggest that sustained phonation is an inappropriate task to investigate vowel articulation in early PD. In contrast, monologue was the most sensitive in differentiating between controls and PD patients, with classification accuracy up to 80%. Measurements of vowel articulation were able to capture even minor abnormalities in speech of PD patients with no perceptible dysarthria. In conclusion, impaired vowel articulation may be considered as a possible early marker of PD. A certain type of speaking task can exert significant influence on vowel articulation. Specifically, complex tasks such as monologue are more likely to elicit articulatory deficits in parkinsonian speech, compared to other speaking tasks.

Targeted motor rehabilitation dissociates corticobulbar versus corticospinal dysfunction in an animal model of Parkinson's disease

BACKGROUND

Recent evidence suggests that motor training may be beneficial for slowing the onset of motor impairments in Parkinson's disease (PD).

OBJECTIVE

To examine the impact of targeted rehabilitation on limb motor and cranial motor function and the corresponding corticospinal and corticobulbar circuits in a rodent model of PD.

METHODS

Baseline performance of limb (reaching) and cranial (licking) motor function were established prior to and 6 weeks following unilateral intrastriatal 6-hydroxydopamine (6-OHDA) infusions. Animals then received 6 weeks of limb motor rehabilitation (LMR) or cranial motor rehabilitation (CMR), after which motor performance was reassessed. Intracortical microstimulation (ICMS) was used to generate motor maps of corresponding corticospinal (forelimb) and corticobulbar (tongue) movement representations within the motor cortex ipsilateral to the 6-OHDA infusion. Quantitative tyrosine hydroxylase (TH) immunohistochemistry was performed to determine levels of striatal TH depletion in 6-OHDA animals using near infrared densitometry.

RESULTS

(1) unilateral intrastriatal dopamine depletion impaired both reaching accuracy and lick force; (2) targeted LMR ameliorated impairments in reaching performance; however, CMR did not improve lick force impairments; (3) unilateral dopamine depletion significantly reduced forelimb but not tongue motor map topography; (4) LMR partially restored forelimb motor maps, whereas CMR did not alter tongue motor maps; and (5) significant correlations were observed between skilled reaching accuracy, forelimb motor map area, and TH depletion, but no relationships were revealed for cranial motor function, motor maps, or TH depletion.

CONCLUSIONS

These data demonstrate dissociation between striatal dopamine depletion, limb versus cranial motor function, and targeted motor rehabilitation in a rodent model of PD.

Differential sensitivity of cranial and limb motor function to nigrostriatal dopamine depletion

The present study determined the differential effects of unilateral striatal dopamine depletion on cranial motor versus limb motor function. Forty male Long Evans rats were first trained on a comprehensive motor testing battery that dissociated cranial versus limb motor function and included: cylinder forepaw placement, single pellet reaching, vermicelli pasta handling; sunflower seed opening, pasta biting acoustics, and a licking task. Following baseline testing, animals were randomized to either a 6-hydroxydopamine (6-OHDA) (n=20) or control (n=20) group. Animals in the 6-OHDA group received unilateral intrastriatal 6-OHDA infusions to induce striatal dopamine depletion. Six-weeks following infusion, all animals were re-tested on the same battery of motor tests. Near infrared densitometry was performed on sections taken through the striatum that were immunohistochemically stained for tyrosine hydroxylase (TH). Animals in the 6-OHDA condition showed a mean reduction in TH staining of 88.27%. Although 6-OHDA animals were significantly impaired on all motor tasks, limb motor deficits were more severe than cranial motor impairments. Further, performance on limb motor tasks was correlated with degree of TH depletion while performance on cranial motor impairments showed no significant correlation. These results suggest that limb motor function may be more sensitive to striatal dopaminergic depletion than cranial motor function and is consistent with the clinical observation that therapies targeting the nigrostriatal dopaminergic system in Parkinson's disease are more effective for limb motor symptoms than cranial motor impairments.

Evaluation of speech impairment in early stages of Parkinson's disease: a prospective study with the role of pharmacotherapy

Despite the initial reports showing beneficial effects of dopaminergic treatment on speech in Parkinson's disease (PD), more recent studies based upon valid measurements have not approved any improvement of speech performance under pharmacotherapy. The aim of this study was to analyze the effect of treatment initiation on the progression of speech impairment in PD, using novel evaluation criteria. Nineteen de novo patients with PD were tested and retested within 2 years after the introduction of antiparkinsonian therapy. As controls, 19 age-matched individuals were recorded. Speech examination included sustained phonation, fast syllable repetition, reading text, and monolog. Quantitative acoustic analyses of the key aspects of speech based on Gaussian kernel distribution, statistical decision-making theory, and healthy speech observation were used to assess the improvement or deterioration of speech. A trend for speech performances to improve was demonstrated after treatment mainly in quality of voice, intensity variability, pitch variability, and articulation. The treatment-related improvement differed in various aspects of speech for individual PD patients. Improvements in vowel articulation and pitch variability correlated with treatment-related changes in bradykinesia and rigidity, whereas voice quality and loudness variability improved independently. Using a novel approach of acoustic analysis and advanced statistics, improvements in speech performance can be demonstrated in PD patients after the introduction of antiparkinsonian therapy. Moreover, changes in speech articulation and pitch variability appear to be related with dopaminergic responsiveness of bradykinesia and rigidity. Therefore, speech may be a valuable marker of disease progression and treatment efficacy in PD.

Functional neuroanatomy of vocalization in patients with Parkinson's disease

In Parkinson's disease (PD) both speech production and self-monitoring of voiced speech are altered.

METHODS

In our previous study we used functional magnetic resonance imaging (fMRI) to examine which brain areas are involved in overt reading in nine female PD patients (mean age 66.0 ± 11.6 years) compared with eight age-matched healthy female controls (mean age 62.2 years ± 12.3). Here we performed the post-hoc seed-based functional connectivity analysis of our data to assess the functional connectivity between the periaqueductal gray matter (PAG; i.e. the core subcortical structure involved in human vocalization) and other brain regions in the same groups of PD patients and controls.

RESULTS

In PD patients as compared with controls we observed increased connectivity between PAG and basal ganglia, posterior superior temporal gyrus, supramarginal and fusiform gyri and inferior parietal lobule on the right side. In the PD group, the connectivity strength in the right putamen and the right sypramarginal gyrus was correlated with variability of pitch while the connectivity strength in the right posterior superior temporal gyrus and in the right inferior parietal lobule was correlated with speech loudness.

CONCLUSION

We observed functional reorganization in PD patients as compared with controls in both the motor basal ganglia-thalamo-cortical circuitry and cortical areas known to be engaged in-auditory and somatosensory feedback control of voiced speech. These changes were hemisphere-specific and might either reflect effects of dopaminergic treatment or at least partially successful compensatory mechanisms involved in early-stage PD.

Deep brain stimulation of caudal zona incerta and subthalamic nucleus in patients with Parkinson's disease: effects on voice intensity

Deep brain stimulation of the subthalamic nucleus (STN-DBS) in patients with Parkinson's disease (PD) affects speech inconsistently. Recently, stimulation of the caudal zona incerta (cZi-DBS) has shown superior motor outcomes for PD patients, but effects on speech have not been systematically investigated. The aim of this study was to compare the effects of cZi-DBS and STN-DBS on voice intensity in PD patients. Mean intensity during reading and intensity decay during rapid syllable repetition were measured for STN-DBS and cZi-DBS patients (eight patients per group), before- and 12 months after-surgery on- and off-stimulation. For mean intensity, there were small significant differences on- versus off-stimulation in each group: 74.2 (2.0) dB contra 72.1 (2.2) dB (P = .002) for STN-DBS, and 71.6 (4.1) dB contra 72.8 (3.4) dB (P = .03) for cZi-DBS, with significant interaction (P < .001). Intensity decay showed no significant changes. The subtle differences found for mean intensity suggest that STN-DBS and cZi-DBS may influence voice intensity differently.

Perception of speech by individuals with Parkinson's disease: a review

A few clinical reports and empirical studies have suggested a possible deficit in the perception of speech in individuals with Parkinson's disease. In this paper, these studies are reviewed in an attempt to support clinical anecdotal observations by relevant empirical research findings. The combined evidence suggests a possible deficit in patients' perception of their own speech loudness. Other research studies on the perception of speech in this population were reviewed, in a broader scope of the perception of emotional prosody. These studies confirm that Parkinson's disease specifically impairs patients' perception of verbal emotions. However, explanations of the nature and causes of this perceptual deficit are still limited. Future research directions are suggested.

A cognitive-perceptual approach to conceptualizing speech intelligibility deficits and remediation practice in hypokinetic dysarthria

Hypokinetic dysarthria is a common manifestation of Parkinson's disease, which negatively influences quality of life. Behavioral techniques that aim to improve speech intelligibility constitute the bulk of intervention strategies for this population, as the dysarthria does not often respond vigorously to medical interventions. Although several case and group studies generally support the efficacy of behavioral treatment, much work remains to establish a rigorous evidence base. This absence of definitive research leaves both the speech-language pathologist and referring physician with the task of determining the feasibility and nature of therapy for intelligibility remediation in PD. The purpose of this paper is to introduce a novel framework for medical practitioners in which to conceptualize and justify potential targets for speech remediation. The most commonly targeted deficits (e.g., speaking rate and vocal loudness) can be supported by this approach, as well as underutilized and novel treatment targets that aim at the listener's perceptual skills.

Effects of medication and subthalamic nucleus deep brain stimulation on tongue movements in speakers with Parkinson's disease using electropalatography: a pilot study

Parkinson's disease (PD) affects speech in the majority of patients. Subthalamic nucleus deep brain stimulation (STN-DBS) is particularly effective in reducing tremor and rigidity. However, its effect on speech is variable. The aim of this pilot study was to quantify the effects of bilateral STN-DBS and medication on articulation, using electropalatography (EPG). Two patients, PT1 and PT2, were studied under four conditions: on and off medication and ON and OFF stimulation. The EPG protocol consisted of a number of target words with alveolar and velar stops, repeated 10 times in random order. The motor part III of the Unified Parkinson Disease Rating Scale (UPDRS) indicated significantly improved motor scores in the ON stimulation condition in both patients. However, PT1's articulation patterns deteriorated with stimulation whereas PT2 showed improving articulatory accuracy in the same condition. The results revealed different effects of stimulation and medication on articulation particularly with regard to timing. The study quantified less articulatory undershoot for velar stops in comparison to alveolars. Furthermore, the findings provided preliminary evidence that stimulation with medication has a more detrimental effect on articulation than stimulation without medication.

Subthalamic nucleus deep brain stimulation changes velopharyngeal control in Parkinson's disease

PURPOSE

Adequate velopharyngeal control is essential for speech, but may be impaired in Parkinson's disease (PD). Bilateral subthalamic nucleus deep brain stimulation (STN DBS) improves limb function in PD, but the effects on velopharyngeal control remain unknown. We tested whether STN DBS would change aerodynamic measures of velopharyngeal control, and whether these changes were correlated with limb function and stimulation settings.

METHODS

Seventeen PD participants with bilateral STN DBS were tested within a morning session after a minimum of 12h since their most recent dose of anti-PD medication. Testing occurred when STN DBS was on, and again 1h after STN DBS was turned off, and included aerodynamic measures during syllable production, and standard neurological ratings of limb function.

RESULTS

We found that PD participants exhibited changes with STN DBS, primarily consistent with increased intraoral pressure (n=7) and increased velopharyngeal closure (n=5). These changes were modestly correlated with measures of limb function, and were correlated with stimulation frequency.

CONCLUSION

Our findings suggest that STN DBS may change velopharyngeal control during syllable production in PD, with greater benefit associated with low frequency stimulation. However, DBS demonstrates a more subtle influence on speech-related velopharyngeal control than limb motor control. This distinction and its underlying mechanisms are important to consider when assessing the impact of STN DBS on PD.

LEARNING OUTCOMES

As a result of this activity, the participant will be able to (1) describe the effects of deep brain stimulation on limb and speech function; (2) describe the effects of deep brain stimulation on velopharyngeal control; and (3) discuss the possible reasons for differences in limb outcomes compared with speech function with deep brain stimulation of the subthalamic nucleus.

Aspectos respiratorios, posturais e vocais da Doença de Parkinson: considerações teóricas

TEMA: manifestações respiratórias, posturais e vocais, associadas aos estágios da Doença de Parkinson (DP) e suas possíveis inter-relações. OBJETIVO: revisar a literatura, a fim de descrever as características respiratórias, posturais e vocais associadas aos estágios na DP e suas possíveis inter-relações. CONCLUSÃO: Na DP, a etiologia das manifestações respiratórias é multifatorial, sendo obstrutivas; restritivas; relacionadas à bradicinesia, à rigidez e às alterações posturais; fraqueza da musculatura; anormalidades na musculatura laríngea; interferência da medicação antiparkisoniana. A postura em flexão altera a dinâmica corporal, interferindo nas funções estomatognáticas e na relação tóraco-abdominal. As alterações vocais podem estar presentes desde os estágios iniciais com diminuição dos tempos máximos de fonação e da intensidade vocal; adução glótica incompleta; fendas glóticas; tremor e instabilidade fonatória; perturbações de frequência e de intensidade; e qualidade vocal alterada. Os déficits na força muscular respiratória se refletem no menor suporte respiratório à emissão vocal e, por consequência, na diminuição da intensidade vocal e dos tempos máximos de fonação. Do mesmo modo, a postura em flexão gera desvantagem biomecânica à atividade respiratória, com menor expansão e redução dos volumes pulmonares, e déficit na excursão diafragmática. Os distúrbios respiratórios, posturais e/ou vocais, à medida que a DP evolui, de acordo com os seus estágios, tendem ao maior comprometimento, apresentando efeitos na comunicação verbal e não-verbal.

Speech motor program maintenance, but not switching, is enhanced by left-hemispheric deep brain stimulation in Parkinson's disease

Speech reaction time (SRT) was measured in a response priming protocol in 12 participants with Parkinson's disease (PD) and hypokinetic dysarthria "on" and "off" left-hemispheric deep brain stimulation (DBS). Speech preparation was measured during speech motor programming in two randomly ordered speech conditions: speech maintenance and switching. Double blind testing was completed in participants with DBS of globus pallidus pars interna (GPi) (n = 5) or subthalamic nucleus (STN) (n = 7). SRT was significantly faster in the maintenance vs switch task, regardless of DBS state. SRT was faster in the speech maintenance task "on" stimulation, while there was no difference in speech switching "on" and "off" DBS. These data suggest that left-hemispheric DBS may have differential effects on aspects of speech preparation in PD. It is hypothesized that speech maintenance improvements may result from DBS-induced cortical enhancements, while the lack of difference in switching may be related to inhibition deficits mediated by the right-hemisphere. Alternatively, DBS may have little influence on the higher level motor processes (i.e., motor planning) which it is believed the switch task engaged to a greater extent than the maintenance task.

Subthalamic nucleus deep brain stimulation changes speech respiratory and laryngeal control in Parkinson's disease

Adequate respiratory and laryngeal motor control are essential for speech, but may be impaired in Parkinson's disease (PD). Bilateral subthalamic nucleus deep brain stimulation (STN DBS) improves limb function in PD, but the effects on respiratory and laryngeal control remain unknown. We tested whether STN DBS would change aerodynamic measures of respiratory and laryngeal control, and whether these changes were correlated with limb function and stimulation parameters. Eighteen PD participants with bilateral STN DBS were tested within a morning session after a minimum of 12 h since their most recent dose of anti-PD medication. Testing occurred when DBS was on, and again 1 h after DBS was turned off, and included aerodynamic measures during syllable production, and standard clinical ratings of limb function. We found that PD participants exhibited changes with DBS, consistent with increased respiratory driving pressure (n = 9) and increased vocal fold closure (n = 9). However, most participants exceeded a typical operating range for these respiratory and laryngeal control variables with DBS. Changes were uncorrelated with limb function, but showed some correlation with stimulation frequency and pulse width, suggesting that speech may benefit more from low-frequency stimulation and shorter pulse width. Therefore, high-frequency STN DBS may be less beneficial for speech-related respiratory and laryngeal control than for limb motor control. It is important to consider these distinctions and their underlying mechanisms when assessing the impact of STN DBS on PD.

Speech and Cognitive-Linguistic Function in Parkinson's Disease

Purpose: Parkinson's disease is among the most common of the motor-based progressive neurologic disorders. This article provides a review of the motor, cognitive, sensory-perceptual, and linguistic deficits that may occur as a result of the loss of dopaminergic neurons, which causes Parkinson's disease.

Method: A review of the literature regarding the nature of Parkinson's disease points out the primary triad of symptoms, which are tremor, rigidity, and bradykinesia. Descriptions of these cardinal symptoms are discussed, as are the non-motor symptoms frequently seen in this disorder, including cognitive changes, sensory-perceptual deficits, and occasionally, linguistic deficits. Dysarthria and dysphagia are frequently seen as a result of the motor deficits associated with Parkinson's disease.

Conclusions: Much has been learned about the pathogenesis of Parkinson's disease, which has led to improved pharmacologic, surgical, and behavioral management. Speech-language pathologists (SLPs) need to be aware of these advances in order to better assess and treat patients and educate families.

Patient-specific model-based investigation of speech intelligibility and movement during deep brain stimulation

BACKGROUND/AIMS

Deep brain stimulation (DBS) is widely used to treat motor symptoms in patients with advanced Parkinson's disease. The aim of this study was to investigate the anatomical aspects of the electric field in relation to effects on speech and movement during DBS in the subthalamic nucleus.

METHODS

Patient-specific finite element models of DBS were developed for simulation of the electric field in 10 patients. In each patient, speech intelligibility and movement were assessed during 2 electrical settings, i.e. 4 V (high) and 2 V (low). The electric field was simulated for each electrical setting.

RESULTS

Movement was improved in all patients for both high and low electrical settings. In general, high-amplitude stimulation was more consistent in improving the motor scores than low-amplitude stimulation. In 6 cases, speech intelligibility was impaired during high-amplitude electrical settings. Stimulation of part of the fasciculus cerebellothalamicus from electrodes positioned medial and/or posterior to the center of the subthalamic nucleus was recognized as a possible cause of the stimulation-induced dysarthria.

CONCLUSION

Special attention to stimulation-induced speech impairments should be taken in cases when active electrodes are positioned medial and/or posterior to the center of the subthalamic nucleus.

Lombard's effect's implication in intensity, fundamental frequency and stability on the voice of individuals with Parkinson's disease

Parkinson's disease affects the central nervous system resulting in voice quality alterations. It is typically resistant to drug therapy and often persists despite extensive behavioural speech and language therapy. Previous findings show that masking noise will produce a consistent increase in voice intensity in most normal individuals (Lombard's effect).

AIM

we evaluated Lombard's effect's implication in intensity, fundamental frequency and stability on the voice of individuals with Parkinson's disease (N=17).

MATERIAL AND METHODS

through acoustic analysis, we evaluated intensity alterations and fundamental frequency, before and after white masking noise 40, 70 and 90 dBSL intensities, as well as variations during each vocalization and compared with a control group (N=16).

RESULTS

voice intensity varied according to masking intensity, tending to non-linear increases in both groups and gender. Fundamental frequency varied, tending to non-linear increase in both groups and gender. Improvement stability occurred in fundamental frequency and vocal intensity.

CONCLUSION

Lombard's effect increased intensity, fundamental frequency and improves voice stability on these patients.

STUDY

clinical and experimental.

Speech treatment for Parkinson's disease

Researchers estimate that 89% of people with Parkinson's disease (PD) have speech and voice disorders including disorders of laryngeal, respiratory and articulatory function. Despite the high incidence of speech and voice impairment, studies suggest that only 3-4% of people with PD receive speech treatment. Here, we review the literature on the characteristics and features of speech and voice disorders in people with PD and the types of treatment techniques available (medical, surgical and behavioral), with a focus on behavioral therapies. We provide a summary of the current status of the field of speech treatment in PD and recommendations for implementation of the current efficacy of treatment interventions. Directions for future research, including a speculative viewpoint on how the field will evolve in 5 years time, are discussed.

Speech and Swallowing in Parkinson's Disease

Dysarthria and dysphagia occur frequently in Parkinson's disease (PD). Reduced speech intelligibility is a significant functional limitation of dysarthria, and in the case of PD is likely related articulatory and phonatory impairment. Prosodically-based treatments show the most promise for addressing these deficits as well as for maximizing speech intelligibility. Communication-oriented strategies also may help to enhance mutual understanding between a speaker and listener. Dysphagia in PD can result in serious health issues, including aspiration pneumonia, malnutrition, and dehydration. Early identification of swallowing abnormalities is critical so as to minimize the impact of dysphagia on health status and quality of life. Feeding modifications, compensatory strategies, and therapeutic swallowing techniques all have a role in the management of dysphagia in PD.

Pearls in patient selection for deep brain stimulation

BACKGROUND

Deep brain stimulation (DBS) has emerged as an important treatment for medication refractory movement and neuropsychiatric disorders. General neurologists and even general practitioners may be called upon to screen potential candidates for DBS. The patient selection process plays an important role in this procedure.

REVIEW SUMMARY

In this article, we discuss "pearls" for the clinician who may be called upon to identify appropriate candidates for DBS. Additionally, we will discuss the important points that should be considered when referring patients for surgical intervention.

CONCLUSION

Diagnosis, response to levodopa, cognitive status, psychiatric status, access to care, and patient expectations are all essential elements of the patient selection process for DBS. These areas must be adequately addressed prior to any surgical procedure.

Implicações do efeito Lombard sobre a intensidade, freqüência fundamental e estabilidade da voz de indivíduos com doença de Parkinson

A Doença de Parkinson afeta o sistema nervoso central resultando em alterações qualitativas da voz que pouco melhoram com o tratamento farmacológico e com a fonoterapia tradicional. Estudos mostram que o mascaramento auditivo leva ao aumento da intensidade da voz em indivíduos normais (Efeito Lombard). OBJETIVO: Avaliar implicações do efeito Lombard sobre a intensidade, freqüência fundamental e estabilidade da voz de indivíduos com doença de Parkinson (N=17). FORMA DE ESTUDO: Estudo clínico e experimental. Material e Métodos: Através de análise acústica, avaliamos as alterações de intensidade e freqüência fundamental, antes e depois da exposição a mascaramento auditivo "white noise", em 40, 70 e 90 dBNS, bem como as variações durante cada emissão e comparamos com um grupo controle (N=16). RESUTADOS: A intensidade de emissão vocal variou de acordo com a intensidade de mascaramento, tendendo a aumento não-linear, ocorrendo também nos grupos Parkinson e controle, não sendo influenciado pelo sexo. A freqüência fundamental da emissão vocal variou, tendendo a aumento não-linear, em ambos os grupos e sexos. Ocorreu melhora da estabilidade, tanto com relação à freqüência quanto à intensidade de emissão vocal. CONCLUSÃO: O Efeito Lombard elevou a intensidade e freqüência fundamental e melhorou a estabilidade da voz desses pacientes.

A relação da postura corporal com a prosódia na doença de parkinson: estudo de caso

OBJETIVO: investigar a associação entre a postura corporal e a prosódia em indivíduos com Doença de Parkinson. MÉTODOS: estudo de corte transversal realizado com cinco sujeitos com Doença de Parkinson da cidade de Santa Maria, Estado do Rio Grande do Sul, em 2006. Utilizaram-se avaliações da prosódia lingüística e emocional bem como da postura corporal. A análise estatística utilizada foi descritiva. RESULTADOS: foram estudados quatro sujeitos do sexo masculino e um sujeito do sexo feminino com idades entre 37 e 53 anos. Três sujeitos encontravam-se no estágio I, um sujeito no estágio III e um sujeito no estágio IV da doença conforme a escala de classificação da função motora Hohen &Yahr, todos sob o uso de medicação e apresentando os sinais da tríade característica da patologia (rigidez, tremor, bradicinesia) bem como as alterações posturais típicas. Na comparação entre prosódia emocional e prosódia lingüística, encontrou-se melhor desempenho na prosódia emocional e não se evidenciou associação entre os estágios da patologia e alterações na postura corporal e prosódia. CONCLUSÃO: as alterações posturais são sinais característicos da Doença de Parkinson, assim como alterações na prosódia lingüística e emocional. A ocorrência de alterações posturais foi elevada entre os parkinsonianos. Os sujeitos apresentaram melhor performance na prosódia emocional. Não houve evidências de que os estágios da doença estivessem associados às alterações da prosódia e da postura corporal.

Speech production in Parkinson's disease: II. Acoustic and electropalatographic investigation of sentence, word and segment durations

Previous investigations employing electropalatography (EPG) have identified articulatory timing deficits in individuals with acquired dysarthria. However, this technology is yet to be applied to the articulatory timing disturbance present in Parkinson's disease (PD). As a result, the current investigation aimed to use EPG to comprehensively examine the temporal aspects of articulation in a group of nine individuals with PD at sentence, word and segment level. This investigation followed on from a prior study (McAuliffe, Ward and Murdoch) and similarly, aimed to compare the results of the participants with PD to a group of aged (n = 7) and young controls (n = 8) to determine if ageing contributed to any articulatory timing deficits observed. Participants were required to read aloud the phrase "I saw a _ today" with the EPG palate in-situ. Target words included the consonants /l/, /s/ and /t/ in initial position in both the /i/ and /a/ vowel environments. Perceptual investigation of speech rate was conducted in addition to objective measurement of sentence, word and segment duration. Segment durations included the total segment length and duration of the approach, closure/constriction and release phases of EPG consonant production. Results of the present study revealed impaired speech rate, perceptually, in the group with PD. However, this was not confirmed objectively. Electropalatographic investigation of segment durations indicated that, in general, the group with PD demonstrated segment durations consistent with the control groups. Only one significant difference was noted, with the group with PD exhibiting significantly increased duration of the release phase for /la/ when compared to both the control groups. It is, therefore, possible that EPG failed to detect lingual movement impairment as it does not measure the complete tongue movement towards and away from the hard palate. Furthermore, the contribution of individual variation to the present findings should not be overlooked.

Perceptions of effort during handgrip and tongue elevation in Parkinson's disease

BACKGROUND

Fatigue and the accompanying perception of effort are often heightened in Parkinson's disease.

OBJECTIVES

To compare performance on three sense-of-effort tasks between patients with PD and matched neurologically normal control subjects.

METHODS

Sixteen PD subjects and 16 normal subjects performed three tasks to assess sense of effort: self-ratings of effort using direct-magnitude estimation, generating pressures at various levels of effort, and sustaining a submaximal level of effort. The latter two tasks were done with handgrip and tongue elevation.

RESULTS

Two of the three tasks successfully differentiated the groups. Subjects with PD provided significantly higher ratings of effort for general daily activities and for speech. During the constant-effort task, pressure curves decayed more rapidly for the PD subjects.

CONCLUSIONS

Performance by PD subjects on the constant-effort task resembled that by normal adults who were pre-fatigued in previous experiments. Results support greater than normal sense-of-effort related to fatigue in PD, and provide preliminary validation of a performance-based physiologic task to assess abnormal sense of effort in this population.

Acoustic voice assessment in Parkinson's disease patients submitted to posteroventral pallidotomy

Long-term complications in levodopa treated Parkinson's disease (PD) patients caused a resurgence of interest in pallidotomy as an option of treatment. However, postoperative complications such as speech disorders can occur.

PURPOSE

The aim of this study is to evaluate the acoustic voice in PD patients, before and after posteroventral pallidotomy.

METHOD

Twelve patients with PD were submitted to neurological and voice assessments during the off and on phases, in the pre-operative, 1st and 3rd post-operative months. The patients were evaluated with the UPDRS and the vocal acoustic parameters -- f0, NHR, jitter, PPQ, Shimmer, APQ (using the software MultiSpeech-Kay Elemetrics-3700).

RESULTS

The off phase UPDRS scores revealed a tendency to improvement at the 1st month and the off phase worsened. The shimmer and APQ improved.

CONCLUSION

This study shows that pallidotomy has little improvement on functional use of communication of PD patients.

Effects of neurosurgical management of Parkinson's disease on speech characteristics and oromotor function

The present study examined the effects of neurosurgical management of Parkinson's disease (PD), including the procedures of pallidotomy, thalamotomy, and deep-brain stimulation (DBS) on perceptual speech characteristics, speech intelligibility, and oromotor function in a group of 22 participants with PD. The surgical participant group was compared with a group of 25 non-neurologically impaired individuals matched for age and sex. In addition, the study investigated 16 participants with PD who did not undergo neurosurgical management to control for disease progression. Results revealed that neurosurgical intervention did not significantly change the surgical participants' perceptual speech dimensions or oromotor function despite significant postoperative improvements in ratings of general motor function and disease severity. Reasons why neurosurgical intervention resulted in dissimilar outcomes with respect to participants' perceptual speech dimensions and general motor function are proposed.

Effects of different electrical parameter settings on the intelligibility of speech in patients with Parkinson's disease treated with subthalamic deep brain stimulation

We evaluated the effects of different electrical parameter settings on the intelligibility of speech in patients with Parkinson's disease (PD) bilaterally treated with deep brain stimulation (DBS) in the subthalamic nucleus (STN). Ten patients treated with DBS for 15 +/- 5 months (mean, SD) with significant (P < 0.01) symptom reduction (Unified Parkinson's Disease Rating Scale III) were included. In the medication off condition, video laryngostroboscopy was performed and then, in random order, 11 DBS parameter settings were tested. Amplitude was increased and decreased by 25%, frequency was varied in the range 70 to 185 pps, and each of the contacts was tested separately as a cathode. The patients read a standard running text and five nonsense sentences per setting. A listener panel transcribed the nonsense sentences as perceived and valued the quality of speech on a visual analogue scale. With the patients' normally used settings, there was no significant (P = 0.058) group difference between DBS OFF and ON, but in four patients the intelligibility deteriorated with DBS ON. The higher frequencies or increased amplitude caused significant (P < 0.02) impairments of intelligibility, whereas changing the polarity between the separate contacts did not. The settings of amplitude and frequency have a major influence on the intelligibility of speech, emphasizing the importance of meticulous parameter adjustments when programming DBS to minimize side effects related to speech.

Treatments for dysarthria in Parkinson's disease

Dysarthria in Parkinson's disease can be characterised by monotony of pitch and loudness, reduced stress, variable rate, imprecise consonants, and a breathy and harsh voice. Use of levodopa to replenish dopamine concentrations in the striatum seems to improve articulation, voice quality, and pitch variation, although some studies show no change in phonatory parameters. Traditional speech therapy can lead to improvement of dysarthria, and intensive programmes have had substantial beneficial effects on vocal loudness. Unilateral surgical lesions of subcortical structures are variably effective for the alleviation of dysarthria, whereas bilateral procedures typically lead to worsening of speech production. Among deep-brain stimulation procedures, only stimulation of the subthalamic nucleus improves some motor components of speech although intelligibility seems to decrease after surgery. Due to the variable treatment effects on parkinsonian speech, management of dysarthria is still challenging for the clinician and should be discussed with the patient.

Geriatric rehabilitation. 3. Physical medicine and rehabilitation interventions for common disabling disorders1∗1No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors(s) or upon any organization with which the author(s) is/are associated.∗Key references

This self-directed learning module highlights physical medicine and rehabilitation (PM and R) interventions for common disorders that cause disability in older adults. It is part of the study guide on geriatric rehabilitation in the Self-Directed Physiatric Education Program for practitioners and trainees in PM and R and geriatric medicine. This article specifically focuses on PM and R interventions for arthritides, fractures, cardiovascular disorders, peripheral vascular disease, amputations, pulmonary disorders, cancer, stroke, traumatic brain injury, Parkinson's disease, spinal cord injury, peripheral neuropathies, and diabetic complications.

OVERALL ARTICLE OBJECTIVE

To summarize the physical medicine and rehabilitation interventions for commonly disabling conditions of older adults.

Lateralized effects of subthalamic nucleus stimulation on different aspects of speech in Parkinson's disease

In this report, we have analyzed the effects of left and right STN stimulation separately on different aspects of speech. Significant differences were found between left and right stimulation. It appears that selective left-sided stimulation has a profoundly negative effect on prosody, articulation and hence intelligibility. Right-sided stimulation does not display this side-effect. There is no significant difference in speech characteristics between bilateral stimulation on and off. We suggest that a balanced tuning of bilateral basal ganglia networks is necessary for speech, and that the left circuit is probably dominant.

The Effects of Intensive Voice Treatment on Facial Expressiveness in Parkinson Disease

OBJECTIVE

The purpose of the present retrospective study was to examine the effects of intensive voice therapy on facial expression in Parkinson disease.

BACKGROUND

Parkinson disease (PD) often presents with symptoms that reduce communicative effectiveness on multiple levels, including decreased vocal loudness and reduced facial mobility. Recent advances in voice treatment have provided the first short- and long-term efficacy data indicating improvements in voice and speech following intensive voice therapy (Lee Silverman Voice Treatment [LSVT]). Anecdotal reports from both clinicians and patients indicate that the LSVT also has a positive impact on facial expression. These observations suggest a need to investigate more directly the effects of voice therapy on facial movement and expressiveness in PD.

METHOD

Forty-four individuals with idiopathic PD participated in this study. Video data were taken from recordings of individuals with PD who had received either one month of phonation-based treatment (LSVT) or respiratory treatment (RT) as part of a large treatment efficacy study designed to examine the effects of different types of therapy on speech and voice in PD. Twenty-second video samples of all subjects taken before and after treatment were paired and played at random without sound to trained raters, who judged each pair of video clips for facial mobility and engagement. All recordings were made while subjects were engaged in conversational speech.

RESULTS

Inter-rater reliability was extremely high (0.90) for both the rating of facial mobility and engagement. Overall, members of the LSVT group received more ratings of increased facial mobility (P = 0.036) and engagement (P = 0.056) following treatment relative to members of the RT group. In addition, the extent of change for facial mobility after treatment was perceived as greater (P = 0.05) for the LSVT group than for the RT group.

CONCLUSIONS

These results indicate that intensive voice therapy may have a positive effect on facial expressivity in PD. Such findings lend support to contemporary theories relating multiple expressive modalities (e.g., voice, face, and gesture) and suggest that targeting voice may be an effective and efficient way to influence expressive output in general.

Softly spoken strokes: two patients with marked hypophonia as a feature of strokes involving the anterior thalamus

Two patients with strokes involving thalamic structures are described. Both displayed marked hypophonia as part of their clinical syndromes. This speech disorder and its possible localizing value are discussed.

Hypophonia in Parkinson's disease: neural correlates of voice treatment revealed by PET

OBJECTIVE

To investigate the neural correlates of hypophonia in individuals with idiopathic PD (IPD) before and after voice treatment with the Lee Silverman Voice Treatment method (VT) using (15)O-H(2)O PET.

METHODS

Regional cerebral blood flow (rCBF) changes associated with overt speech-motor tasks relative to the resting state were measured in the IPD subjects before and after VT, and in a group of healthy control volunteers.

RESULTS

Behavioral measures of voice loudness significantly improved following treatment. Before VT, patients had strong speech-related activations in motor and premotor cortex (M1-mouth, supplementary motor cortex [SMA], and inferior lateral premotor cortex [ILPm]), which were significantly reduced post-VT. Similar to the post-treatment session, premotor activations were absent (SMA) or below statistical threshold (M1-mouth) in the healthy control group. In addition, following VT treatment, significant right-sided activations were present in anterior insular cortex, caudate head, putamen, and dorsolateral prefrontal cortex (DLPFC). Finally, the VT-induced neural changes were not present with transient experimenter-cued increases of loudness in VT-untreated patients.

CONCLUSIONS

Effective improvement of IPD hypophonia following voice treatment with VT was accompanied by a reduction of cortical motor-premotor activations, resembling the functional pattern observed in healthy volunteers and suggesting normalization, and additional recruitment of right anterior insula, caudate head, putamen, and DLPFC. This treatment-dependent functional reorganization suggests a shift from an abnormally effortful (premotor cortex) to a more automatic (basal ganglia, anterior insula) implementation of speech-motor actions.

Short-term effectiveness of intensive multidisciplinary rehabilitation for people with Parkinson's disease and their carers

OBJECTIVE

To evaluate the short-term effectiveness of an intensive multidisciplinary rehabilitation programme for people with Parkinson's disease and their carers.

DESIGN

Observational, with assessments before and after intervention.

SETTING

An elderly care day unit in a district general hospital in south-east England.

SUBJECTS

One hundred and eighteen people with Parkinson's disease and no cognitive impairment, and their carers.

INTERVENTION

Participants attended the day hospital in groups of six patients with their carers for one day per week over six consecutive weeks. After assessment, they received individual treatment from a specialist team. Weekly group activities included relaxation and talks from experts.

OUTCOME MEASURES

Patients and carers were assessed for: health-related quality of life, psychological well-being, social services need, perceptions of the programme. Patients were additionally assessed for mobility, gait and speech. Carers were assessed for strain.

RESULTS

After treatment significant improvements were recorded in patients' mobility and gait (p < 0.05), speech (p < 0.001), depression (p = 0.029), health-related quality of life (p = 0.001). People with more advanced disease at baseline gained significantly more from treatment (p < or = 0.04). Carers were less depressed and had higher health-related quality of life than patients at baseline (p < 0.001) and no improvements in these indicators were recorded after treatment. A high unmet need for social services was identified in 31% of participants, and 10% of carers were found in danger of being unable to continue caring. Participants reported knowledge gains and high levels of satisfaction with both individual therapies and group activities.

CONCLUSIONS

This intensive co-ordinated programme provided immediate benefits to people with Parkinson's disease and their carers.

Phonatory characteristics of parkinsonian speech before and after morning medication: the ON and OFF states

After prolonged treatment with L-dopa, patients with Parkinson's disease (PD) experience fluctuations in motor performance. Changes in voice production have been documented perceptually during periods of fluctuation, but few quantitative changes have been found. The purpose of this study is to examine the acoustic-phonatory characteristics of PD speech before and after taking medication, to determine if fluctuations affected phonation. Nine PD patients participated in this study. Multiple analyses were performed, and revealed that fundamental frequency (Fo) variability in vowels and mean Fo were higher, while intensity range was lower in PD patients compared to controls. When the PD subjects were examined after versus before medication, group differences were small, but phonatory improvements were seen in individual subjects. Discussion focuses on physiological changes and variability in PD, and implications of response fluctuations to speech production.

LEARNING OUTCOMES

As a result of this activity, the participant will be able to (1) acquire knowledge and understanding of PD and the voice characteristics commonly associated with PD and (2) understand the effects of L-dopa-related fluctuations on voice production in PD.

Speech motor stability in IPD: effects of rate and loudness manipulations

Increasing phonatory effort, an integral component of the Lee Silverman Voice Treatment, LSVT, has been identified as an effective management strategy for adults with hypokinetic dysarthria associated with Parkinsonism. The present study compares the effects of increased loudness on lower lip movements to those of changes in speaking rate, another approach to the treatment of hypokinetic dysarthria. Movements of the lower lip/jaw during speech were recorded from 8 adults with IPD, 8 healthy aged adults, and 8 young adults. The spatiotemporal index (STI), a measure of spatial and temporal variability, revealed that for all speaker groups slow rate was associated with the most variability. Compared to the other conditions, STI values from the loud condition were closest to those from habitual speech. Also, the normalized movement pattern for the loud condition resembled that of habitual speech. It is hypothesized that speaking loudly is associated with a spatial and temporal organization that closely resembles that used in habitual speech, which may contribute to the success of the LSVT.

Clinicoanatomic studies in dysarthria: review, critique, and directions for research

More than 30 years ago, Darley, Aronson, and Brown (1969) proposed clinicoanatomic correlations for seven perceptual types of dysarthria. These correlations have not been systematically re-examined even though imaging technologies developed in recent years provide the means to do so. This review considers data from published imaging studies as well as data from selected medical interventions to evaluate the current state of knowledge that relates lesion site to the nature of a speech disturbance. Although the extant data are not sufficient to allow a complete evaluation of the seven types of dysarthria described by Darley et al., relevant information has been reported on lesions of the pyramidal pathway, extrapyramidal pathway, and cerebellum. In general, the results are best explained by an equivalence mode of brain-behavior relationship in which a type of dysarthria is associated with a lesion in one of two or more brain structures. Criteria also are proposed for future studies of clinicoanatomic relationships in neurogenic communication disorders.