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

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.

Acoustic analysis of prosody in Sydenham's chorea

There are few studies of language and speech in patients with Sydenham's chorea (SC). We have done an acoustic analysis of fundamental frequency (F0), duration and intensity of declarative and interrogative sentences made by 20 SC patients, 20 patients with rheumatic fever (RF) without chorea, and compared them with 20 healthy age-matched controls (CO). Each group included 12 females. We found that there is no difference between the RF and CO groups in all studied parameters. Patients with SC, however, presented with a speech characterized by decreased F0 range (difference between minimum and maximum F0), shorter duration of sentences, and higher intensity of the first syllable of sentences. The findings were not influenced by the nature of the sentences (i.e. , declarative or interrogative), but for all variables they were significantly more severe in males than females. In conclusion, we have demonstrated that patients with acute SC have an impairment of modulation of F0 and longer duration of emission of sentences, resulting in a monotone and slow speech. This pattern is similar to what has been described in other basal ganglia illnesses, such as Parkinson's disease, Huntington's disease and Wilson's disease.

Sequential changes in motor speech across a levodopa cycle in advanced Parkinson's disease

Previous research has indicated that in Parkinson's disease (PD) some motor speech characteristics are changed by levodopa administration, while others are not. In advanced PD, the time course of these changes and the correlations with motor performance have not been sufficiently investigated. The purpose was to investigate the sequential changes of respiratory, articulatory, and phonatory speech characteristics across a levodopa drug cycle, using spirometry, acoustic, and motor speech analysis. Seven patients with advanced PD were included. All patients were evaluated sequentually at 15 minute intervals before and following levodopa intake. Data were analysed using repeated measures ANOVA and non-parametric analysis. Significant changes were found in motor function, vital capacity, and standard deviation of the diadochokinetic period. A trend was present for shimmer and frequency of the first formant. Significant inter-individual differences in the sequential changes were demonstrated for nearly all evaluated parameters. The conclusion is that, in advanced PD, the evaluation of speech characteristics at one moment after levodopa administration is not representative of an entire drug cycle and that an individualized evaluation of an entire drug cycle is warranted before initiation of a speech-language pathology program.

[Dysarthria across Parkinson's disease progression. Natural history of its components: dysphonia, dysprosody and dysarthria]

Dysarthria refers to a collective name for a group of neurologic motor speech disorders, resulting from central and/or peripheral nervous system abnormalities. Speech alteration in Parkinson's disease, so-called hypokinetic dysarthria, presents with prosodic insufficiency, related to a monotony of pitch and intensity, a reduction of accentuation, variable speech rate and possible phoneme imprecision. In most cases, voice is harsh and breathy. This symptom can affect both voice and speech quality, as well as prosody and intelligibility. As a consequence, many patients complain about speech impairments, which affect their communication in daily living activities. Perceptual and instrumental assessments require different and numerous investigation methods, which use may help to further understand the specific dysarthria pathophysiology. This is of importance in order to adjust treatments for dysarthria; as a matter of fact, dopa-therapy, functional neurosurgery or even behavioural speech therapy have variable effects on voice and speech quality in Parkinson's disease.

Voice onset time in Parkinson disease

Research has found that speaking rate has an effect on voice onset time (VOT). Given that Parkinson disease (PD) affects speaking rate, the purpose of this study was to examine VOT with the effect of rate removed (VOT ratio), along with the traditional VOT measure, in individuals with PD. VOT and VOT ratio were examined in 9 individuals with PD (before and after taking medication), along with 9 matched controls. Place of articulation and vowel height had significant effects on VOT and VOT ratio for all groups, and there were no PD versus control differences. PD medication had a greater effect on VOT than VOT ratio, reflecting a rate-related VOT change rather than a pure VOT change. These data support the usefulness of examining both VOT and VOT ratio with individuals with PD, as this allows for dissociation between rate-related VOT changes and true VOT changes.

LEARNING OUTCOMES

The reader will be able to understand and describe: (1) voice onset time (VOT) and VOT ratio; (2) how VOT and VOT ratio are affected in individuals with Parkinson disease; and (3) the effect of medication on VOT and VOT ratio.

Progression of dysprosody in Parkinson's disease over time--a longitudinal study

Parkinsonian speech or hypokinetic dysarthria results from a multidimensional impairment of phonation, articulation, and prosody. Although the dysprosody in Parkinson's disease (PD) is well described (alterations in speech rate and pause time, speech intensity and pitch variation), little is known about alterations of these single prosodic parameters over a longer time course. The objective of this study is to analyze changes of speech rate and pitch variation in patients with PD over time and to compare these findings with healthy controls. Patients with PD (N = 50; 27 male and 23 female) and n = 50 age-matched healthy controls (25 male, 25 female) were tested and retested after at least 7 months (mean: 25.02; median: 21; SD: 17.44; range: 7-79 months). In the PD group, motor impairment according to UPDRS motor score was similar at first and second visit. The participants had to accomplish a standardized four sentence reading task. The acoustical analysis was performed using a standard head-worn microphone for voice recordings and commercial audio software (WaveLab). For the determination of intonation based upon fundamental frequency (F(0)) variation, we used a computer analysis program (Praat). Articulatory velocity was determined by measurement of syllable rate and pause ratios. In the PD group, total speech rate (syllables per second related to total speech time/TSR) and net speech rate declined from first to second examination, especially in the male patients, but showed no significant differences to the control group. The course of pitch variation revealed some gender particularities. Whereas female patients' pitch variability declined over time, male patients' intonation variability remained relatively stable. F(0) variation in male and female patients with PD were significantly reduced compared with the control group in the first examination and the follow up as well. Progression of prosodic impairment over time showed no correlation to disease duration or UPDRS motor score. Some aspects of dysprosody in PD show characteristic changes over time, but show no clear correlation with general motor impairment as assessed by UPDRS motor score. Therefore, we suspect that the underlying mechanism could be independent from dopaminergic deficits.

Reduction of dopamine synaptic activity: degradation of 50-kHz ultrasonic vocalization in rats

Vocal deficits are prevalent and debilitating in Parkinson's disease. These deficits may be related to the initial pathology of the nigrostriatal dopamine neurons and resulting dopamine depletion, which contributes to dysfunction of fine motor control in multiple functions. Although vocalization in animals and humans may differ in many respects, we evaluated complex (50-kHz) ultrasonic mate calls in 2 rat models of Parkinson's disease, including unilateral infusions of 6-hydroxydopamine to the medial forebrain bundle and peripheral administration of a nonakinesia dose of the dopamine antagonist haloperidol. We examined the effects of these treatments on multiple aspects of the acoustic signal. The number of trill-like (frequency modulated) 50-kHz calls was significantly reduced, and appeared to be replaced by simpler (flat) calls. The bandwidth and maximum intensity of simple and frequency-modulated calls were significantly decreased, but call duration was not. Our findings suggest that the nigrostriatal dopamine pathway is involved to some extent in fine sensorimotor function that includes USV production and complexity.

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.

Fundamental Frequency Change During Offset and Onset of Voicing in Individuals with Parkinson Disease

SUMMARY

After years of treatment with the medication levodopa, most individuals with Parkinson disease (PD) experience fluctuations in response to their medications. Although relatively consistent perceptual voice improvements have been documented to correspond with these fluctuations, consistent quantitative data to support this finding are lacking. This mismatch may have occurred because most of this phonation research has centered on long-term phonatory measures (ie, across speaking samples and prolonged vowel tasks). The current study examined short-term phonatory behavior in individuals with PD, specifically examining fundamental frequency (F0) at the offset and onset of phonation, before and after a voiceless consonant. The F0 analysis at phonatory offset supported the conclusion that individuals with PD have difficulty with the rapid offset of voicing, and that they are stopping vocal fold vibration primarily through vocal fold abduction (without adding tension). The F0 analysis at phonatory onset revealed that all groups use some laryngeal tension at the initiation of voicing. The tension was lowest for the PD participants who were in their OFF medication state, and it was highest for the age-matched control participants and the PD participants in their ON medication states.

Voice abnormalities and their relation with motor dysfunction in Parkinson's disease

OBJECTIVE

To evaluate changes in perceptual and several acoustic parameters of voice in patients with Parkinson's disease (PD) and to find out any relation with these parameters and motor components of Unified Parkinson's Disease Rating Scale (UPDRS) in this patient group.

MATERIALS AND METHODS

Twenty patients with PD (12 male and 8 female) were given objective and subjective voice tests and results were compared with those of 20 age- and sex-matched controls. Patient's perceptual voice analysis was assessed using GRBAS scale including Grade of Dysphonia, Roughness, Breathiness, Asthenia and Strain items. Measurements for objective voice analysis, acoustic assessment tests including frequency perturbation [jitter (jitt)%], intensity perturbation [shimmer (shim)%], noise to harmonic ratio (NHR), fundamental frequency (F0), variability of fundamental frequency (vF0), diadochokinetic rate (DDK) and maximum phonation time (MPT) were used. An assessment of disability caused by voice disorders was scored according to the Voice Handicap Index (VHI) by the patient. All subjects also underwent videolaryngostroboscopic (VLS) examination. Motor components of UPDRS and acoustic parameters of voice were investigated for any correlations.

RESULTS

Compared with controls, roughness (P = 0.15), breathiness (P = 0.004) and asthenia (P = 0.031) values of males and breathiness (P = 0.043) and asthenia (P = 0.023) values of females were higher in patients with PD. Mean VHI scores of patients with PD were higher for both male and female patients (P = 0.0001 for male, P = 0.002 for female). The mean values for MPT (P = 0.02) and DDK (P = 0.025) were shorter in patients with PD. Jitt%, shim% and mean F0 values were similar among the two groups. But mean vF0 values were significantly higher in male patients with PD (P = 0.05). On VLS examination, non-closure glottic pattern was found to be more frequent in the PD group.

CONCLUSION

Although it is well known that pathophysiological changes in PD affect the voice, the present study found only few significant correlations between motor component of UPDRS and voice parameters.

The Degenerative Dysarthrias: A Window into Critical Clinical and Research Issues

Although diversity of symptoms and urgency of needs pose many challenges, management of the degenerative dysarthrias is a crucial aspect of clinical practice. The purpose of this article is to review current research literature on selected degenerative dysarthrias including those associated with Parkinson's disease, multiple sclerosis, and amyotrophic lateral sclerosis. These dysarthrias are prevalent yet represent distinct patterns of underlying neuropathology, symptoms, age of onset, and rate of progression. Literature searches including the period 1997-2006 yielded 148 different studies reporting data on communication issues related to dysarthria. By far the largest category of studies was that which provided a basic description of speech production including the neurophysiologic, acoustic, or perceptual properties of dysarthria. Other categories included management (assessment and treatment) and the psychosocial consequences of dysarthria. While the topic of management of degenerative dysarthria is a focused one, it provides a window into many issues critical to the field of communication disorders including fundamental properties of speech production, development of evidence-based treatment techniques, the staging of these techniques into an effective management sequence, and the psychosocial consequences of communication disorders along with techniques to maintain communicative participation in the face of degenerative conditions.

The Lee Silverman Voice Treatment® for voice, speech and other orofacial disorders in patients with Parkinson’s disease

Parkinson’s disease (PD) impairs voice, speech, swallowing and facial expressions, thus affecting communication, food intake, work, socialization and overall health and quality of life. This article reviews current research on the characteristics and features of these disorders in individuals with PD, and the types of treatment techniques available (medical, surgical or behavioral), with emphasis on the Lee Silverman Voice Treatment (LSVT®) as the treatment of choice to improve voice, speech and other orofacial functions. LSVT addresses major deficits underlying voice and speech in PD, namely, impaired scaling of movement amplitude and poor perception and self-regulation of vocal output. Based upon this, LSVT emphasizes increased amplitude of vocal output through intensive training in increased vocal loudness (with good voice quality), recalibration of vocal loudness perception and self-regulation of vocal effort. The potential contribution of LSVT and analogous behavioral treatment approaches to neural plasticity is also addressed, as are directions for future research.

Acoustic analysis of clear versus conversational speech in individuals with Parkinson disease

A number of studies have been devoted to the examination of clear versus conversational speech in non-impaired speakers. The purpose of these previous studies has been primarily to help increase speech intelligibility for the benefit of hearing-impaired listeners. The goal of the present study was to examine differences between conversational and clear speech in individuals with Parkinson disease (PD). Twelve individuals were recorded producing conversational and clear speech. Acoustic analysis revealed that individuals with PD used some of the same clear speech strategies used by non-impaired speakers. Specifically, clear speech in PD was characterized by decreased articulation rate, increased mean fundamental frequency (F(o)), and increased speaking F(o)S.D. compared to conversational speech. The discussion examines the possibility that individuals with PD may have been independently applying a clear speech strategy based on their habitually increased percent pause values. Discussion also focuses on implications of the present findings to management of individuals with PD, and research implications.

LEARNING OUTCOMES

As a result of this activity, the participant will be able to (1) describe the characteristics of clear speech produced by non-disordered individuals, (2) describe the acoustic characteristics of clear and conversational speech produced by individuals with Parkinson disease; and (3) describe the strategies individuals with Parkinson disease use when asked to produce clear 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.

Parkinsonian speech disfluencies: effects of L-dopa-related fluctuations

The excess dopamine theory of stuttering (Wu et al., 1997) contends that stuttering may be related to excess levels of the neurotransmitter dopamine in the brain. As Parkinson's disease (PD) patients commonly exhibit changes in dopamine levels accompanied by changes in motor performance, the present study examined disfluency in PD patients to gain information on the role of dopamine in speech disfluencies. Nine PD patients with no history of developmental stuttering were recorded once before and twice after taking their morning medication (on separate days). They read a passage and produced a monologue. Within-word and overall speech disfluencies were calculated at each recording. Through motor testing, it was inferred that participants had relatively low dopamine levels before taking medication, and relatively high dopamine levels after taking medication. There were no group changes in disfluency levels when the low-dopamine and high-dopamine states were compared. There were, however, significant differences in percent disfluencies between the PD participants and age-matched controls. The results of this study do not strongly support the excess dopamine theory of stuttering. Rather, the disfluency changes exhibited by individual participants support a hypothesis that speech disfluencies may be related to increases or decreases in dopamine levels in the brain.

EDUCATIONAL OBJECTIVES

The reader will learn about: (1). the characteristics of disfluent speech exhibited by speakers with Parkinson's disease. (2). The effect of L-dopa based medications on disfluencies of Parkinsonian speakers. (3). The complex role brain dopamine levels may play in disfluent speaking behavior.