Bidirectional interference between speech and postural stability in individuals with Parkinson's disease

Talking while Walking After Concussion: Acute effects of concussion on speech pauses and gait speed

Background

Deficits in dual-tasks (DT) are frequently observed post-concussion (i.e., mild Traumatic Brain Injury). However, traditional DT may not be relevant to daily life. Walking while talking elicits DT costs in healthy adults and is part of daily life.

Objective

We investigated the effect of concussion on walking with extemporaneous speech and explored relationships between DT and acute symptoms.

Methods

Participants with recent concussion (<14 days post-injury) and controls completed three tasks: single-task gait without speaking (ST G ), single-task speaking without walking (ST S ) and walking while speaking (DT). Silent pauses in speech audio reflected cognitive performance, and gait was quantified using inertial sensors. We used linear mixed models to compare groups and conditions and explored associations with self-reported symptoms.

Results

Both concussion (n=19) and control (n=18) groups exhibited longer speech pauses ( p < 0.001), slower walking speeds ( p < 0.001), and slower cadence ( p < 0.001) during the DT compared to ST conditions. There were no group differences or interactions for speech pauses ( p > 0.424). The concussion group walked slower ( p = 0.010) and slowed down more during DT than the control group (group*task p = 0.032). Vestibular symptoms strongly associated with ST speech pause duration ( ρ = 0.72), ST gait speed ( ρ = -0.75), and DT gait speed ( ρ = -0.78).

Conclusions

Extemporaneous speech is well-practiced, but challenging to complete while walking post-concussion. Strong associations between DT outcomes and vestibular-related symptoms suggest DT deficits vary with post-concussion symptomology. DT deficits may be deleterious to daily tasks post-concussion.

Effects of a Concurrent Working Memory Task on Speech Acoustics in Parkinson's Disease

PURPOSE

The purpose of this study was to determine the effect of a concurrent working memory task on acoustic measures of speech in individuals with Parkinson's disease (PD).

METHOD

Individuals with PD and age- and sex-matched controls performed a speaking task with and without a Stroop-like concurrent working memory task. Cepstral peak prominence, low-to-high spectral energy ratio, fundamental frequency (fo) standard deviation, articulation rate, pause duration, articulatory-acoustic vowel space, relative fo, mean voice onset time (VOT), and VOT variability were calculated for each condition. Mixed-model analyses of variance were performed to determine the effects of group, condition (presence of the concurrent working memory task), and their interaction on the acoustic measures.

RESULTS

All measures except for VOT variability, mean pause duration, and relative fo offset differed between people with and without PD. Cepstral peak prominence, articulation rate, and relative fo offset differed as a function of condition. However, no measures indicated disparate effects of condition as a function of group.

CONCLUSION

Although differentially impactful on limb motor function in PD, here a concurrent working memory task was not found to be differentially disruptive to speech acoustics in PD.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24759648.

Clinical availability of eye movement during reading

Eyes provide valuable information for neurological diagnosis. So far, the use of diagnostic devices to analyze eye movement is limited. We explored whether the analysis of eye movements can be efficacious. Patients with Parkinson's disease (PD) (n = 29), spinocerebellar degeneration (SCD) (21), progressive supranuclear palsy (PSP) (19), and control individuals (19) participated in this study. The patients read aloud two sets of sentences displayed on a monitor: one was displayed horizontally, and the other vertically. Parameters such as eye movement speed, travel distance, and fixation/saccade ratio were extracted, and comparisons between groups were performed. Maneuvers of eye movements were also subjected to image classification using deep learning. Reading velocity and fixation/saccade ratio were altered in the PD group, and the SCD group exhibited ineffective eye movements due to dysmetria and nystagmus. Vertical gaze parameters showed aberrant values in the PSP group. Vertical written sentences were more sensitive than horizontal ones in detecting these abnormalities. In the regression analysis, vertical reading indicated a high accuracy in identifying each group. The machine learning analysis showed more than 90 % accuracy in distinguishing between the control and SCD groups and between the SCD and PSP groups. Analyzing eye movements is useful and easily applicable.

Continuous theta burst stimulation over right cerebellum for speech impairment in Parkinson's disease: study protocol for a randomized, sham-controlled, clinical trial

Background

Speech impairment is a common symptom of Parkinson's disease (PD) that worsens with disease progression and affects communication and quality of life. Current pharmacological and surgical treatments for PD have inconsistent effects on speech impairment. The cerebellum is an essential part of sensorimotor network that regulates speech production and becomes dysfunctional in PD. Continuous theta-burst stimulation (cTBS) is a non-invasive brain stimulation technique that can modulate the cerebellum and its connections with other brain regions.

Objective

To investigate whether cTBS over the right cerebellum coupled with speech-language therapy (SLT) can improve speech impairment in PD.

Methods

In this randomized controlled trial (RCT), 40 patients with PD will be recruited and assigned to either an experimental group (EG) or a control group (CG). Both groups will receive 10 sessions of standard SLT. The EG will receive real cTBS over the right cerebellum, while the CG will receive sham stimulation. Blinded assessors will evaluate the treatment outcome at three time points: pre-intervention, post-intervention, and at a 12-week follow-up. The primary outcome measures are voice/speech quality and neurobehavioral parameters of auditory-vocal integration. The secondary outcome measures are cognitive function, quality of life, and functional connectivity determined by resting-state functional magnetic resonance imaging (fMRI).

Significance

This trial will provide evidence for the efficacy and safety of cerebellar cTBS for the treatment of speech impairment in PD and shed light on the neural mechanism of this intervention. It will also have implications for other speech impairment attributed to cerebellar dysfunctions.

Clinical trial registration

www.chictr.org.cn, identifier ChiCTR2100050543.

Assessment of communication competence in acquired communication disorders: A systematic scoping review

PURPOSE

Individuals with acquired communication disorders (ACDs) experience reduced ability to participate independently in activities of daily life, and maintain interpersonal relationships and psychosocial wellbeing. Communication interventions are designed to optimise communication competence in personally relevant everyday activities. However, the assessment tools speech-language pathologists (SLPs) typically utilise to evaluate communication competence in everyday life are not ideal. To explore the range and availability of assessments used in research to examine functional communication in adults with ACDs.

METHOD

Five databases (Medline, CINAHL, EMBASE, SCOPUS and PsycINFO) were searched to identify assessment or intervention studies evaluating functional communication in adults with ACDs. Functional communication tools utilised in each study were identified. Extracted tools were categorised according to type, target population, consideration of multimodal communication, person-specificity, consideration of context, availability, administration/analysis time and availability of normative/psychometric data.

RESULT

Forty functional communication assessment tools were included. Just over half the tools were performance-based (n = 25), examined different modes of communication (n = 26) and/or considered context (n = 23). Only 14 tools were person-specific. Many of the most comprehensive tools were out of print or considered excessively time consuming to administer and analyse.

CONCLUSION

A paucity of accessible, time-efficient yet comprehensive tools to assess functional communication in ACDs may limit clinical practice and client outcomes. More versatile functional communication assessments incorporating individualised contexts, and the use of modern communication technologies are recommended.

Attentional Demand of Motor Speech Encoding: Evidence From Parkinson's Disease

PURPOSE

While the involvement of attention in utterance planning is well established at the conceptual and lexical levels, the attentional demands of postlexical processes are still debated. This study investigates the involvement of attentional resources on motor speech encoding during utterance production in the context of Parkinson's disease (PD), a population allowing to assess if the attentional demands observed in a dual-task paradigm (the dual-task costs [DTCs]) are explained by postlexical difficulties and not solely by executive impairment.

METHOD

Speech production was analyzed in a dual-task paradigm with 30 participants presenting with motor speech disorders due to hypokinetic dysarthria in the context of PD. The dual-task comprised an automatic speech task in which participants recited the days of the week and two nonverbal tasks evaluating processing speed and inhibition. The severity of dysarthria and performance in several executive tests (inhibition, verbal fluency, and cognitive shifting) were used as potential predictors of the DTCs.

RESULTS

Individuals with PD exhibited a DTC on the nonverbal tasks and on the speech task when the secondary task was inhibition (the most difficult one). Additionally, the severity of dysarthria and a poorer performance in cognitive shifting predicted a more severe DTC on speech rate. Finally, modulation of the magnitude of the DTCs was observed, depending on the difficulty of the nonverbal secondary task.

CONCLUSION

The results suggest that, in PD, postlexical processes require attentional resources and cognitive shifting is related to dual-task performance in speech.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21265893.

Global Coherence and Cognition in Parkinson's Disease

PURPOSE

This study compared global coherence (GC) in individuals with Parkinson's disease (PD) to a healthy older adult (HOA) group during single (sitting) and dual (stationary cycling) tasks. Additionally, it explored the relationship between GC and cognition in PD.

METHOD

Thirty-seven individuals with PD and 19 HOAs participated in the prospective, cross-sectional study. Participants completed discourse monologues elicited using published prompts while seated and while pedaling a stationary bicycle. Four rating levels of GC were analyzed (GC1 = no relationship to the topic, GC2 = remote relationship, GC3 = conditional relationship, and GC4 = complete relationship) using a published protocol with good interrater reliability and test-retest stability. Participants completed a battery of cognitive tasks, from which four latent factors were extracted: processing speed, working memory, inhibition, and updating.

RESULTS

Linear mixed modeling identified significant effects of GC level and GC level interactions with group, processing speed, and inhibition. The Group × GC Level interaction reflected that the PD group had a higher proportion of GC2 and GC1 utterances and fewer GC4 utterances than the HOA group. No differences between single and dual task conditions were found. Faster speed of processing predicted more GC4 utterances, whereas slower speed of processing predicted more G1 utterances. Better inhibition predicted fewer GC2 utterances. Group also predicted GC4 and GC2 proportions.

CONCLUSIONS

Individuals with PD experienced greater difficulties with GC than HOAs. Processing speed and inhibition contributed significantly to GC across groups. Analysis of GC should be considered an informative addition to assessment of communicative effectiveness in PD.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.20416056.

Subthalamic stimulation breaks the balance between distal and axial signs in Parkinson's disease

In Parkinson’s disease (PD), the effects of both L_dopa and subthalamic deep brain stimulation (STN-DBS) are known to change cost-valuation. However, this was mostly studied through reward-effort task involving distal movements, while axial effort, less responsive to treatments, have been barely studied. Thus, our objective was to compare the influence of both L_dopa and STN-DBS on cost-valuation between two efforts modalities: vowel production (as an example of axial movement) and hand squeezing (as an example of distal movement). Twelve PD patients were recruited to participate in this study. The task consisted in deciding whether to accept or reject trials based on a reward-effort trade-off. Participants performed two blocks with hand squeezing, and two with vowel production, in the four treatment conditions (L_dopaOn/Off; STN-DBS On/Off). We found that STN-DBS changed the ratio difference between hand and phonation efforts. Vowel production effort was estimated easier to perform with STN-DBS alone, and harder when associated with L_dopa. The difference between hand and phonation efforts was correlated with quality of life in Off/Off and On L_dopa alone conditions, and with impulsive assessment On STN-DBS alone. We highlighted that STN-DBS could introduce an imbalance between the actual motor impairments and their subjective costs. With this finding, we also suggest paying particular attention to the different treatment effects that should be expected for axial and distal movement dysfunctions.

Reciprocal Influence of Mobility and Speech-Language: Advancing Physical Therapy and Speech Therapy Cotreatment and Collaboration for Adults With Neurological Conditions

Mobility and speech-language impairments and limitations in adults with neurological conditions manifest not in isolated anatomical components but instead in the individual-environment system and are task-dependent. Optimization of function thus requires interprofessional care to promote participation in meaningful life areas within appropriate task and environmental contexts. Cotreatment guidelines (ie, the concurrent intervention of disciplines) were established by the physical therapy, occupational therapy, and speech-language and hearing professional organizations nearly 2 decades ago to facilitate seamless interprofessional care. Despite this, cotreatment between physical therapy and speech therapy remains limited. The purpose of this Perspective article is to encourage physical therapists and speech-language pathologists to increase interprofessional collaboration through cotreatment in the management of adults with neurological conditions. Evidence from pediatrics and basic motor control literature points toward reciprocal interactions between speech-language and mobility. We provide recommendations for clinical practice with an emphasis on the gains each discipline can provide the other. This Perspective is rooted in the International Classification of Functioning, Disability and Health model and ecological theory.

IMPACT

The goals of speech therapy and physical therapy are complementary and mutually supportive. Enhanced cotreatment, and collaboration more generally, between physical therapists and speech-language pathologists in the management of adults with neurological conditions can augment task-relevant conditions to improve function.

Attention in post-lexical processes of utterance production: Dual-task cost in younger and older adults

There is a general agreement that speaking requires attention at least for conceptual and lexical processes of utterance production. However, conflicting results have been obtained with dual-task paradigms using either repetition tasks or more generally tasks involving limited loading of lexical selection. This study aimed to investigate whether post-lexical processes recruit attentional resources. We used a new dual-task paradigm in a set of experiments where a continuous verbal production task involved either high or low demand on lexical selection processes. Experiment 1 evaluates lexical and post-lexical processes with a semantic verbal fluency task, whereas Experiments 2 and 3 focus on post-lexical processes with a non-propositional speech task. In each experiment, two types of non-verbal secondary tasks were used: processing speed (simple manual reaction times) or inhibition (Go/No-go). In Experiment 1, a dual-task cost was observed on the semantic verbal fluency task and each non-verbal task. In Experiment 2, a dual-task cost appeared on the non-verbal tasks but not on the speech task. The same paradigm was used with older adults (Experiment 3), as increased effort in post-lexical processes has been associated with ageing. For older adults, a dual-task cost was also observed on the non-propositional verbal task when speech was produced with the inhibition non-verbal task. The results suggest an attentional cost on post-lexical processes and strategic effects in the resolution of the dual-task.

Tracking the Costs of Clear and Loud Speech: Interactions Between Speech Motor Control and Concurrent Visuomotor Tracking

Purpose Prior work has demonstrated that competing tasks impact habitual speech production. The purpose of this investigation was to quantify the extent to which clear and loud speech are affected by concurrent performance of an attention-demanding task. Method Speech kinematics and acoustics were collected while participants spoke using habitual, loud, and clear speech styles. The styles were performed in isolation and while performing a secondary tracking task. Results Compared to the habitual style, speakers exhibited expected increases in lip aperture range of motion and speech intensity for the clear and loud styles. During concurrent visuomotor tracking, there was a decrease in lip aperture range of motion and speech intensity for the habitual style. Tracking performance during habitual speech did not differ from single-task tracking. For loud and clear speech, speakers retained the gains in speech intensity and range of motion, respectively, while concurrently tracking. A reduction in tracking performance was observed during concurrent loud and clear speech, compared to tracking alone. Conclusions These data suggest that loud and clear speech may help to mitigate motor interference associated with concurrent performance of an attention-demanding task. Additionally, reductions in tracking accuracy observed during concurrent loud and clear speech may suggest that these higher effort speaking styles require greater attentional resources than habitual speech.

Dual-task speech performance in multiple sclerosis

BACKGROUND

Although extant dual-task studies suggest cognitive-motor interference may magnify existing non-speech motor impairments in multiple sclerosis (MS), cognitive-speech motor interference in MS has not been studied. This study evaluated the presence of cognitive-speech motor interference in MS and explored within subject differences in speech measures from the single-to dual-task condition for individuals with MS with co-occurring dysarthria and impaired cognition.

METHODS

In this dual-task study, 21 individuals with MS and 21 controls read aloud a sentence (single-task) and completed a cognitive-linguistic task while simultaneously reading aloud a sentence (dual-task). Speech measures included speech and articulation rate, silent pause frequency and duration, and total sentence duration.

RESULTS

Both groups had significantly slower speech in the dual-task condition. Relative to participants with dysarthria, speech rate and sentence duration difference scores approached significance or were significantly greater for participants with MS with dysarthria and cognitive impairment. These difference scores were associated with executive function and processing speed deficits and fewer years of education.

CONCLUSION

Significant negative compounding effects for speech rate and sentence duration suggest that the dual-task paradigm shows promise for identifying individuals with MS with cognitive impairment and dysarthria at increased risk of problems with effective communication. Further research is warranted to replicate this work and evaluate the consequences of these speech aberrancies on communication effectiveness that ultimately may affect employment, social relationships, and quality of life.

Effect of cognitive and motor dual-task on oropharyngeal swallowing in Parkinson's disease

BACKGROUND

Dysphagia frequently occurs in patients with Parkinson's disease (PD) and is associated with severe complications. However, the underlying pathology is poorly understood at present. This study investigated the effect of cognitive and motor dual-task interference on oropharyngeal swallowing in PD.

METHODS

Thirty PD patients (23 men, mean age 65.90 ± 9.32 years, mean Hoehn and Yahr stage 2.62 ± 0.81, mean UPDRS 18.00 ± 7.18) were examined using flexible endoscopic evaluation of swallowing (FEES). FEES was performed during three paradigms: at baseline without interference, during a cognitive dual-task, and during a motor dual-task. Oropharyngeal swallowing function was rated using a score which was validated to detect changes in PD related dysphagia. The three paradigms were compared using a two-way-repetitive-measures-ANOVA and a post-hoc-analysis.

RESULTS

Mean swallowing score in baseline FEES was 10.67 ± 5.89. It significantly increased (worsened) to 15.97 ± 7.62 (p < 0.001) in the motor dual-task and to 14.55 ± 7.49 (p < 0.001) in the cognitive dual-task. Premature bolus spillage and pharyngeal residue both significantly increased during both of the dual-task conditions whereas penetration/aspiration events did not change.

CONCLUSION

Oropharyngeal swallowing in patients with PD is not purely reflexive but requires mental capacity. Additional allocation of attentional resources in the central control of swallowing seems to be an effective compensatory mechanism in PD-related dysphagia: The proposed dual-task protocol may be useful to challenge swallowing functional reserve. Conversely, as a therapeutic strategy, it could be beneficial to focus attention on swallowing and to avoid dual-task situations.

Effects of Concurrent Manual Task Performance on Connected Speech Acoustics in Individuals With Parkinson Disease

Purpose Prior investigations suggest that simultaneous performance of more than 1 motor-oriented task may exacerbate speech motor deficits in individuals with Parkinson disease (PD). The purpose of the current investigation was to examine the extent to which performing a low-demand manual task affected the connected speech in individuals with and without PD. Method Individuals with PD and neurologically healthy controls performed speech tasks (reading and extemporaneous speech tasks) and an oscillatory manual task (a counterclockwise circle-drawing task) in isolation (single-task condition) and concurrently (dual-task condition). Results Relative to speech task performance, no changes in speech acoustics were observed for either group when the low-demand motor task was performed with the concurrent reading tasks. Speakers with PD exhibited a significant decrease in pause duration between the single-task (speech only) and dual-task conditions for the extemporaneous speech task, whereas control participants did not exhibit changes in any speech production variable between the single- and dual-task conditions. Conclusions Overall, there were little to no changes in speech production when a low-demand oscillatory motor task was performed with concurrent reading. For the extemporaneous task, however, individuals with PD exhibited significant changes when the speech and manual tasks were performed concurrently, a pattern that was not observed for control speakers. Supplemental Material https://doi.org/10.23641/asha.8637008.

Drooling in Parkinson's Disease: Evidence of a Role for Divided Attention

Drooling is a frequently reported symptom in Parkinson's Disease (PD) with significant psychosocial impact and negative health consequences including silent aspiration of saliva with the associated risk of respiratory infections. It is suggested that in PD drooling is associated with inefficient oropharyngeal swallowing which reduces the effective clearance of saliva rather than hyper-salivation. This is compounded by unintended mouth opening and flexed posture increasing anterior loss of saliva. It is reported to occur most frequently during cognitively distracting concurrent tasks suggesting an impact from divided attention in a dual-task situation. However, this supposition has not been systematically examined. This study assessed whether frequency of saliva swallows reduced, and drooling severity and frequency increased, when people with PD engaged in a cognitively distracting task. 18 patients with idiopathic PD reporting daytime drooling on the Unified Parkinson's Disease Rating Scale (UPDRS) were recruited. They completed the Radboud Oral Motor Inventory for PD saliva questionnaire and the Montreal Cognitive Assessment. UPDRS drooling score, disease stage, duration, gender, and age were recorded. Swallow frequency and drooling severity and frequency were measured at rest and during a distracting computer-based language task. There was no significant difference between drooling severity at rest and during distraction (Wilcoxon signed rank test z = - 1.724, p = 0.085). There was a significant difference between at rest and distraction conditions for both drooling frequency (Wilcoxon signed rank test z = - 2.041, p = 0.041) and swallow frequency (Wilcoxon signed rank test z = - 3.054, p = 0.002). Participants swallowed less frequently and drooled more often during the distraction task. The frequency of saliva swallows and drooling are affected by divided attention in a dual-task paradigm. Further studies are needed to explore the exact role of attention in saliva management and the clinical applications in assessment and treatment.

Speech Motor Sequence Learning: Effect of Parkinson Disease and Normal Aging on Dual-Task Performance

PURPOSE

Everyday communication is carried out concurrently with other tasks. Therefore, determining how dual tasks interfere with newly learned speech motor skills can offer insight into the cognitive mechanisms underlying speech motor learning in Parkinson disease (PD). The current investigation examines a recently learned speech motor sequence under dual-task conditions.

METHOD

A previously learned sequence of 6 monosyllabic nonwords was examined using a dual-task paradigm. Participants repeated the sequence while concurrently performing a visuomotor task, and performance on both tasks was measured in single- and dual-task conditions.

RESULTS

The younger adult group exhibited little to no dual-task interference on the accuracy and duration of the sequence. The older adult group exhibited variability in dual-task costs, with the group as a whole exhibiting an intermediate, though significant, amount of dual-task interference. The PD group exhibited the largest degree of bidirectional dual-task interference among all the groups.

CONCLUSIONS

These data suggest that PD affects the later stages of speech motor learning, as the dual-task condition interfered with production of the recently learned sequence beyond the effect of normal aging. Because the basal ganglia is critical for the later stages of motor sequence learning, the observed deficits may result from the underlying neural dysfunction associated with PD.

Bidirectional Interference Between Speech and Nonspeech Tasks in Younger, Middle-Aged, and Older Adults

PURPOSE

The purpose of this study was to examine divided attention over a large age range by looking at the effects of 3 nonspeech tasks on concurrent speech motor performance. The nonspeech tasks were designed to facilitate measurement of bidirectional interference, allowing examination of their sensitivity to speech activity. A cross-sectional design was selected to explore possible changes in divided-attention effects associated with age.

METHOD

Sixty healthy participants were separated into 3 groups of 20: younger (20s), middle-aged (40s), and older (60s) adults. Each participant completed a speech task (sentence repetitions) once in isolation and once concurrently with each of 3 nonspeech tasks: a semantic-decision linguistic task, a quantitative-comparison cognitive task, and a manual motor task. The nonspeech tasks were also performed in isolation.

RESULTS

Data from speech kinematics and nonspeech task performance indicated significant task-specific divided attention interference, with divided attention affecting speech and nonspeech measures in the linguistic and cognitive conditions and affecting speech measures in the manual motor condition. There was also a significant age effect for utterance duration.

CONCLUSIONS

The results increase what is known about bidirectional interference between speech and other concurrent tasks as well as age effects on speech motor control.

Does voice amplification increase intelligibility in people with Parkinson's disease?

Background/Aims:

Patients with speech intelligibility difficulties associated with a quiet voice are often prescribed a voice amplifier. This study examined whether artificial voice amplification improved intelligibility in people with Parkinson's disease and whether there was an optimum increase that brought about best improvement.

Methods:

Twelve people diagnosed with Parkinson's disease (mild=4, moderate intelligibility difficulties=8) and five age-matched controls read low predictability sentences in their habitual voice. Audio recordings were digitally manipulated to create samples at +2.3 dB, +5 dB and +10 dB amplification. Listeners transcribed the recorded sentences. The percentage of words correctly identified was compared across levels of amplification and groups.

Results:

Participants with moderate Parkinson's disease were significantly less intelligible than controls in all conditions. Moderately, but not mildly affected participants with Parkinson's disease showed higher intelligibility in the amplified conditions, though statistically significantly only at +2.3 dB. No other significant effects of intensity or interactions with groups were found. At an individual level, some participants showed clear advantages of amplification.

Conclusion:

Based on results from the current participants, potential benefits of amplification cannot be promised to all people with Parkinson's disease. Nevertheless, several provisos regarding methods employed suggest the question can gainfully be pursued using broader measures to assess effects of amplification with more varied groups of people with Parkinson's disease and with other aetiologies where voice production can be an issue.

Lee Silverman Voice Treatment for people with Parkinson's: audit of outcomes in a routine clinic

BACKGROUND

Speaking louder/more intensely represents a longstanding technique employed to manage voice and intelligibility changes in people with Parkinson's. This technique has been formalized into a treatment approach and marketed as the Lee Silverman Voice Treatment (LSVT®) programme. Evidence for its efficacy has been published. Studies to date are dominated by research facility reports from the original LSVT® group or closely associated groups. Evidence for the efficacy of LSVT® in routine clinical settings is lacking.

METHODS & PROCEDURES

We conducted an audit of outcomes for consecutive people with Parkinson's who were offered and completed LSVT® in a routine hospital outpatient setting. In- and exclusion criteria, assessment and treatment protocols followed precisely the methods stipulated by LSVT® Global. Additionally, participants completed the Voice Handicap Index (VHI) and 23 carers completed a visual analogue scale (VAS) for items relating to functional outcomes.

OUTCOMES & RESULTS

Group data (n = 33) revealed statistically significant increases in all objective and subjective measures at the end of treatment, though outcomes on the different measures revealed variable individual responses. Mean intensity increases on prolonged vowel were 9.3 dB post-treatment. Significant gains of mean 7.5 and 6.8 dB were maintained at 12 (n = 25) and 24 months (n = 15) respectively for those available for follow-up. Significant intensity gains occurred for reading post-therapy (mean = 8.5 dB), but changes reverted to statistically non-significant at 12 and 24 months. Intensity increase (mean = 8.5 dB) was significant for monologues post-therapy, but not at 12 and 24 months. Median VHI improvement was statistically significant post-therapy and at 12 months, but not at 24 months. Carer VAS ratings all improved significantly post-therapy; at 12 months only perceived loudness, strain, mumbling and intelligibility remained statistically significantly above baseline. No significant gains persisted to 24 months.

CONCLUSIONS & IMPLICATIONS

LSVT® was successful for most individuals in this study. Not all patients attained significant changes by the end of treatment. Few patients who achieved significant gain at the end of treatment maintained this at 12 or 24 months. Implications for maintenance, interpretation of results in a degenerative condition and implications for further research are discussed.

Multiple factors are involved in the dysarthria associated with Parkinson's disease: a review with implications for clinical practice and research

PURPOSE

Motor speech abnormalities are highly common and debilitating in individuals with idiopathic Parkinson's disease (IPD). These abnormalities, collectively termed hypokinetic dysarthria (HKD), have been traditionally attributed to hypokinesia and bradykinesia secondary to muscle rigidity and dopamine deficits. However, the role of rigidity and dopamine in the development of HKD is far from clear. The purpose of the present study was to offer an alternative view of the factors underlying HKD.

METHOD

The authors conducted an extensive, but not exhaustive, review of the literature to examine the evidence for the traditional view versus the alternative view.

RESULTS

The review suggests that HKD is a highly complex and variable phenomenon including multiple factors, such as scaling and maintaining movement amplitude and effort; preplanning and initiation of movements; internal cueing; sensory and temporal processing; automaticity; emotive vocalization; and attention to action (vocal vigilance). Although not part of the dysarthria, nonmotor factors, such as depression, aging, and cognitive-linguistic abnormalities, are likely to contribute to the overall speech symptomatology associated with IPD.

CONCLUSION

These findings have important implications for clinical practice and research.

Measuring up to speech intelligibility

Improvement or maintenance of speech intelligibility is a central aim in a whole range of conditions in speech-language therapy, both developmental and acquired. Best clinical practice and pursuance of the evidence base for interventions would suggest measurement of intelligibility forms a vital role in clinical decision-making and monitoring. However, what should be measured to gauge intelligibility and how this is achieved and relates to clinical planning continues to be a topic of debate. This review considers the strengths and weaknesses of selected clinical approaches to intelligibility assessment, stressing the importance of explanatory, diagnostic testing as both a more sensitive and a clinically informative method. The worth of this, and any approach, is predicated, though, on awareness and control of key design, elicitation, transcription and listening/listener variables to maximize validity and reliability of assessments. These are discussed. A distinction is drawn between signal-dependent and -independent factors in intelligibility evaluation. Discussion broaches how these different perspectives might be reconciled to deliver comprehensive insights into intelligibility levels and their clinical/educational significance. The paper ends with a call for wider implementation of best practice around intelligibility assessment.

Age-related differences in attentional cost associated with postural dual tasks: increased recruitment of generic cognitive resources in older adults

Dual-task designs have been used widely to study the degree of automatic and controlled processing involved in postural stability of young and older adults. However, several unexplained discrepancies in the results weaken this literature. To resolve this problem, a careful selection of dual-task studies that met certain methodological criteria are considered with respect to reported interactions of age (young vs. older adults)×task (single vs. dual task) in stable and unstable postural conditions. Our review shows that older adults are able to perform a postural dual task as well as younger adults in stable conditions. However, when the complexity of the postural task is increased by dynamic conditions (surface and surround), performance in postural, concurrent, or both tasks is more affected in older relative to young adults. In light of neuroimaging studies and new conceptual frameworks, these results demonstrate an age-related increase of controlled processing of standing associated with greater intermittent adjustments.

The effects of practice on the concurrent performance of a speech and postural task in persons with Parkinson disease and healthy controls

Purpose. Persons with Parkinson disease (PD) demonstrate deficits in motor learning as well as bidirectional interference (the performance of one task concurrently interferes with the performance of another task) during dual-task performance. Few studies have examined the practice dosages necessary for behavioral change in rehabilitation relevant tasks. Therefore, to compare the effects of age and PD on motor learning during dual-task performance, this pilot study examined persons with PD as well as neurologically healthy participants during concurrent performance of postural and speaking tasks. Methods. Seven persons with PD and 7 healthy age-matched and 10 healthy young control subjects were tested in a motion capture facility. Task performances were performed concurrently and recorded during 3 time periods (acquisition (beginning and ending), 48-hour retention, and 1-week retention). Postural control and speech articulatory acoustic variables were measured. Results. Healthy young participants consistently performed better than other groups on all measured postural and speech variables. Healthy young participants showed decreased variability at retention, while persons with PD and healthy age-matched controls were unable to consistently improve their performance as a result of practice. No changes were noted in the speech variables. Conclusion. The lack of consistent changes in motor performance in any of the tasks, except in the healthy young group, suggests a decreased efficiency of motor learning in the age-matched and PD groups and argues for increased practice dosages during balance training.

Levodopa effects on hand and speech movements in patients with Parkinson's disease: a FMRI study

Levodopa (L-dopa) effects on the cardinal and axial symptoms of Parkinson’s disease (PD) differ greatly, leading to therapeutic challenges for managing the disabilities in this patient’s population. In this context, we studied the cerebral networks associated with the production of a unilateral hand movement, speech production, and a task combining both tasks in 12 individuals with PD, both off and on levodopa (L-dopa). Unilateral hand movements in the off medication state elicited brain activations in motor regions (primary motor cortex, supplementary motor area, premotor cortex, cerebellum), as well as additional areas (anterior cingulate, putamen, associative parietal areas); following L-dopa administration, the brain activation profile was globally reduced, highlighting activations in the parietal and posterior cingulate cortices. For the speech production task, brain activation patterns were similar with and without medication, including the orofacial primary motor cortex (M1), the primary somatosensory cortex and the cerebellar hemispheres bilaterally, as well as the left- premotor, anterior cingulate and supramarginal cortices. For the combined task off L-dopa, the cerebral activation profile was restricted to the right cerebellum (hand movement), reflecting the difficulty in performing two movements simultaneously in PD. Under L-dopa, the brain activation profile of the combined task involved a larger pattern, including additional fronto-parietal activations, without reaching the sum of the areas activated during the simple hand and speech tasks separately. Our results question both the role of the basal ganglia system in speech production and the modulation of task-dependent cerebral networks by dopaminergic treatment.

Speech, voice and language in Parkinson’s disease: changes and interventions

SUMMARY This article covers recent developments in the understanding of communication changes in idiopathic Parkinson’s disease and selected issues in intervention. By contrast to earlier narrow considerations of voice and speech, the effects on communication of cognitive–linguistic and prosody perception and production are also highlighted. Decline can occur from the earliest stages, even when listeners perceive no frank changes. Communication may be relatively trouble-free in one-to-one quiet clinical situations but declines in multi-talker, dual/competing task situations. Assessment should reflect this to gain more accurate insights into daily living performance. Currently, therapies focusing on attention-to-effort in voice production and on monitoring the sense of effort and loudness production appear to be most successful. Medical and surgical treatments have little effect on intelligibility and communication and may even exacerbate the situation.

A review of dual-task walking deficits in people with Parkinson's disease: motor and cognitive contributions, mechanisms, and clinical implications

Gait impairments in Parkinson's disease (PD) are exacerbated under dual-task conditions requiring the simultaneous performance of cognitive or motor tasks. Dual-task walking deficits impact functional mobility, which often requires walking while performing concurrent tasks such as talking or carrying an object. The consequences of gait impairments in PD are significant and include increased disability, increased fall risk, and reduced quality of life. However, effective therapeutic interventions for dual-task walking deficits are limited. The goals of this narrative review are to describe dual-task walking deficits in people with PD, to discuss motor and cognitive factors that may contribute to these deficits, to review potential mechanisms underlying dual-task deficits, and to discuss the effect of therapeutic interventions on dual-task walking deficits in persons with PD.