Cynthia Fox

Changes in vocal loudness following intensive voice treatment (LSVT®) in individuals with Parkinson's disease: A comparison with untreated patients and normal age-matched controls

This study assessed the impact of the Lee Silverman Voice Treatment (LSVT®) on vocal loudness [sound pressure level (SPL)] in a group of dysarthric individuals with idiopathic Parkinsons disease (IPD). Pre‐ to post‐treatment changes in SPL in the treated group were compared with changes in voice SPL during the same time in two control groups: individuals with IPD not treated with the LSVT® and in non‐disordered individuals, age‐matched to the patients. All subjects produced the same voice and speech tasks—sustaining vowel phonation, reading the “Rainbow Passage,” producing a short monologue, and describing a picture. These tasks were recorded at three different occasions: just prior to treatment, just after treatment, and 6 months following treatment. The individuals treated with LSVT® increased voice SPL from baseline to post‐treatment by an average of 8 dB and from baseline to 6 months follow‐up by an average of 6 dB. These changes were statistically significant and perceptibly audible. No significant changes in SPL were observed in the control groups during the time corresponding to the treatment and follow‐up. Differences in SPL between the treated and untreated patients at post‐treatment and follow‐up were statistically significant for all voice and speech tasks. These findings, along with others, provide additional support for the efficacy of the LSVT®. Mov. Disord. 16:79–83, 2001.

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.

Vocal Sound Pressure Level and Self-Perception of Speech and Voice in Men and Women With Idiopathic Parkinson Disease

This study compared vocal sound pressure level (SPL) and self-perception of speech and voice in men and women with idiopathic Parkinson disease (PD) and in healthy men and women. Thirty subjects wi...

Speech and swallowing disorders in Parkinson disease.

Purpose of reviewTo review recent research and clinical studies pertaining to the nature, diagnosis, and treatment of speech and swallowing disorders in Parkinson disease. Recent findingsAlthough some studies indicate improvement in voice and speech with dopamine therapy and deep brain stimulation of the subthalamic nucleus, others show minimal or adverse effects. Repetitive transcranial magnetic stimulation of the mouth motor cortex and injection of collagen in the vocal folds have preliminary data supporting improvement in phonation in people with Parkinson disease. Treatments focusing on vocal loudness, specifically LSVT LOUD (Lee Silverman Voice Treatment), have been effective for the treatment of speech disorders in Parkinson disease. Changes in brain activity due to LSVT LOUD provide preliminary evidence for neural plasticity. Computer-based technology makes the Lee Silverman Voice Treatment available to a large number of users. A rat model for studying neuropharmacologic effects on vocalization in Parkinson disease has been developed. New diagnostic methods of speech and swallowing are also available as the result of recent studies. SummarySpeech rehabilitation with the LSVT LOUD is highly efficacious and scientifically tested. There is a need for more studies to improve understanding, diagnosis, prevention, and treatment of speech and swallowing disorders in Parkinson disease.

Qualitative changes in ultrasonic vocalization in rats after unilateral dopamine depletion or haloperidol: A preliminary study

The sensorimotor speech/voice deficits associated with Parkinson disease have been well documented in humans. They are largely resistant to pharmacological and surgical treatment, but respond to intensive speech therapy. The mechanisms underlying this phenomenon are not well understood and are difficult to systematically test in humans. Thus, we turn to the rat as a model. The purpose of this study is to compare the ultrasonic vocalization (USV) of rats in three conditions: control, haloperidol-induced transient dopamine depletion, and unilateral 6-hydroxydopamine (6-OHDA) induced moderately-severe degeneration of dopamine neurons. It was hypothesized that both dopamine-altered conditions would lead to a change in the features of the USV acoustic signal. Results demonstrated that bandwidth decreased in the dopamine-altered rats. This is the first study to document a degradation of the acoustic signal of frequency-modulated 50-kHz calls as a result of interfering with dopamine synaptic transmission in rats. The data suggest that mild transient dopamine depletion with haloperidol or even unilateral degeneration of dopamine neurons is associated with changes in the USV acoustic signal. Dopaminergic dysfunction influences USV quality without reducing the number of calls. This study provides a foundation to examine the role of dopamine in sensorimotor processes underlying USV production and potentially to explore treatments for dopamine deficiency-related impaired vocal outcome.

Intensive voice treatment in Parkinson’s disease: Lee Silverman Voice Treatment

Advances in neuroscience have led to an expanded and improved understanding of neurobiological changes associated with rehabilitation and exercise in Parkinson’s disease (PD). This knowledge has led to a direct clinical impact of increased referral for early and continuous exercise programs for individuals with PD (physical, occupational, speech therapy and general exercise programs) and an increased research focus on the impact of such approaches in humans with PD. The purpose of this article is to examine the role of speech therapy in the landscape of exercise-based interventions for individuals with PD. We will specifically focus on the intensive voice treatment protocol, Lee Silverman Voice Treatment, as an example therapy. This article will briefly review the literature on the characteristics and features of speech and voice disorders in individuals with PD, and will discuss the impact of pharmacological and surgical treatment techniques on these disorders. This will be followed by a focus on behavioral speech treatment, specifically Lee Silverman Voice Treatment, including development of the treatment approach, documenting efficacy, discovery of unexpected outcomes and insights into the mechanism of speech disorders in PD gained from treatment-related changes. This research will be placed in the context of other previous and current speech treatment approaches in development for individuals with PD, and will highlight future directions for research.

LSVT LOUD and LSVT BIG: Behavioral Treatment Programs for Speech and Body Movement in Parkinson Disease

Recent advances in neuroscience have suggested that exercise-based behavioral treatments may improve function and possibly slow progression of motor symptoms in individuals with Parkinson disease (PD). The LSVT (Lee Silverman Voice Treatment) Programs for individuals with PD have been developed and researched over the past 20 years beginning with a focus on the speech motor system (LSVT LOUD) and more recently have been extended to address limb motor systems (LSVT BIG). The unique aspects of the LSVT Programs include the combination of (a) an exclusive target on increasing amplitude (loudness in the speech motor system; bigger movements in the limb motor system), (b) a focus on sensory recalibration to help patients recognize that movements with increased amplitude are within normal limits, even if they feel “too loud” or “too big,” and (c) training self-cueing and attention to action to facilitate long-term maintenance of treatment outcomes. In addition, the intensive mode of delivery is consistent with principles that drive activity-dependent neuroplasticity and motor learning. The purpose of this paper is to provide an integrative discussion of the LSVT Programs including the rationale for their fundamentals, a summary of efficacy data, and a discussion of limitations and future directions for research.

Intensive Amplitude-specific Therapeutic Approaches for Parkinsonʼs Disease: Toward a Neuroplasticity-principled Rehabilitation Model

Recent scientific advances in animal models of Parkinson disease suggest exercise is a legitimate disease-modifying therapeutic option that contributes to behavioral recovery and neurochemical sparing. These data challenge current rehabilitative assumptions and emphasize the need for neuroplasticity-principled exercise-based approaches to challenge the impaired system. We suggest one novel solution-–the intensive practice of amplitude-–a global motor control parameter. Training a single focus (amplitude) across (1) disciplines (physical, occupational, speech therapy), (2) tasks (transfers, activities of daily living, recreation), and (3) motor systems (speech, locomotion, reaching) may provide the complexity, difficulty, and repetition necessary for disease-modification in human Parkinson disease.

Robust fundamental frequency estimation in sustained vowels: Detailed algorithmic comparisons and information fusion with adaptive Kalman filtering

There has been consistent interest among speech signal processing researchers in the accurate estimation of the fundamental frequency (F(0)) of speech signals. This study examines ten F(0) estimation algorithms (some well-established and some proposed more recently) to determine which of these algorithms is, on average, better able to estimate F(0) in the sustained vowel /a/. Moreover, a robust method for adaptively weighting the estimates of individual F(0) estimation algorithms based on quality and performance measures is proposed, using an adaptive Kalman filter (KF) framework. The accuracy of the algorithms is validated using (a) a database of 117 synthetic realistic phonations obtained using a sophisticated physiological model of speech production and (b) a database of 65 recordings of human phonations where the glottal cycles are calculated from electroglottograph signals. On average, the sawtooth waveform inspired pitch estimator and the nearly defect-free algorithms provided the best individual F(0) estimates, and the proposed KF approach resulted in a ∼16% improvement in accuracy over the best single F(0) estimation algorithm. These findings may be useful in speech signal processing applications where sustained vowels are used to assess vocal quality, when very accurate F(0) estimation is required.

Evidence-based treatment of voice and speech disorders in Parkinson disease.

Purpose of review Voice and speech impairments are present in nearly 90% of people with Parkinson disease and negatively impact communication and quality of life. This review addresses the efficacy of Lee Silverman Voice Treatment (LSVT) LOUD to improve vocal loudness (as measured by vocal sound pressure level vocSPL) and functional communication in people with Parkinson disease. The underlying physiologic mechanisms of Parkinson disease associated with voice and speech changes and the strength of the current treatment evidence are discussed with recommendations for best clinical practice. Recent findings Two randomized control trials demonstrated that participants who received LSVT LOUD were significantly better on the primary outcome variable of improved vocSPL posttreatment than alternative and no treatment groups. Treatment effects were maintained for up to 2 years. In addition, improvements have been demonstrated in associated outcome variables, including speech rate, monotone, voice quality, speech intelligibility, vocal fold adduction, swallowing, facial expression and neural activation. Advances in technology-supported treatment delivery are enhancing treatment accessibility. Summary Data support the efficacy of LSVT LOUD to increase vocal loudness and functional communication in people with Parkinson disease. Timely intervention is essential for maximizing quality of life for people with Parkinson disease.