Therapy Instructions: LOUD and INTENT on People with Parkinson's Disease

Abstract: Parkinson’s disease (PD) affects various movements.
Speech production is a motoric behavior, and it is common for individuals with PD to experience verbal communication difficulties. Different treatment instructions could yield diverse outcomes. The present study examined the voice/speech changes under two instructions, “Speak Loud” and “Speak with Intent.”

Description: Parkinson's disease (PD) is the second most prevalent neurodegenerative disease in the United States. People with PD (PWP) lose dopaminergic cells in the Substantia Nigra over time. The Substantia Nigra provides necessary background information to our motoric behaviors by supporting movement amplitudes and displacements. The loss of dopaminergic cells in the Substantia Nigra results in decreased movement amplitude. Therefore, individuals with PD present with small, shuffled gait, micrographia, and decreased facial expressions. Speech production is a motoric behavior that requires precise coordination of respiratory, phonatory, and articulatory movements. Insufficient management of the movements in any one or more areas often negatively affects the voice and speech of PWP.

In general, clinical care for PD is focused on the management of (1) the motor symptoms of the disorder by pharmacologic or instrumental/surgical means (such as Deep Brain Stimulation) and (2) behavioral therapy guided by allied health professionals. Allied health professionals, such as Physical Therapists (PT), Occupational Therapists (OT), and Speech-Language Pathologists (SLP), intend to change the client's behavioral patterns for rehabilitative purposes through therapeutic efforts. Therapists agree that different instructions during therapy sessions could yield diverse treatment outcomes. It is critically important for SLPs to provide optimal instructions in voice therapy for individuals. Therapists are intuitively aware of the effects of different instructions. However, objective measurements of the voices produced under various instructions have not yet been performed.

The present study aims to compare and contrast the effects of two instructions commonly used to address hypophonia secondary to PD. These instructions are "Speak Loud" and "Speak with Intent." The former phrase, "Speak Loud," is the instruction used by the Lee Silverman Voice Treatment (LSVT®) program. LSVT is the most widely implemented and studied remediation program for voice disorders related to PD. The latter phrase, "Speak with Intent," is the instruction used by the SPEAK OUT!® program, developed by Elandary and colleagues in 2010 (Parkinson Voice Project, 2012). The instruction "Speak Loud" is a single-target instruction. Previous studies have reported that this instruction yielded synergic effects of improving other aspects of speech production, such as breath support and articulation. The instruction "Speak with Intent" attempts to focus on the pyramidal system activation to compensate for the decreased or lost function of the extrapyramidal system due to PD. Clinicians often find that no single therapy method is the best for all PWP. The recipients of therapeutic efforts are human beings and not machines. Each client presents a unique combination of symptoms and problems resulting from PD. Also, each individual with PD has different perceptions and attitudes toward his/her/their condition. The present study analyzed quantitative and qualitative aspects of speech produced under (1) natural, (2) "Speak Loud," and (3) "Speak with Intent" instructions.

Seventeen individuals with PD, including nine males and seven females, with a mean age of 69 (SD:7; range: 51- 76), participated in the present study. Data collection was carried out with a single participant at a time in a quiet room. Each participant first recorded his/her/their natural voice. Then, he/she/they recorded the same materials in two additional blocks with different instructions, "Speak Loud" and "Speak with Intent." The presentations of these instructions were randomized to prevent order bias, and a short break took place between the blocks to avoid perseveration. The materials were sustained corner vowels (/a, i, u/) and CAPE-V sentences. The vocal intensity was measured with sustained corner vowel phonation and CAPE-V sentence productions separately for quantitative analyses. The Acoustic Voice Quality Index (AVQI), and its components, Cepstral Peak Prominence (CPP) and Harmonic-to-Noise Ratio (HNR), were measured for qualitative analyses.
The data analyses are currently in progress. The preliminary data suggest that the mean vocal intensity gained with the "Speak Loud" instruction is more prominent in the three corner vowels and CAPE-V sentences than with the "Speak with Intent" instruction. The mean AVQI appeared to have noticeable improvement with the "Speak Loud" instruction, and CPP figures are similar in these two instructions. The mean HNR figures are close in both instructions, with a higher average with the "Speak Loud" instruction. However, there were some cases where the trajectories of the change did not follow the majority of other participants. The examinations of individual data and their possible relationship with other data, such as the participants' responses to V-RQOL questions, are underway.
The present study has only 16 PWP participants without a control group. If future studies replicate the results of the present study with a control group and a greater number of participants, they will potentially provide important information to alter therapy instructions that fit optimally for different individuals with PD.

Presentation Format & Methods: PowerPoint presentation and interactive exchanges with attendees.

Supporting Research: Reference 1: Englert, M., v Latoszek, B. B., & Behlau, M. (2022). Exploring The Validity of Acoustic Measurements and Other Voice Assessments. Journal of Voice.

Supporting Research: Reference 2: Finnimore, A., Theodoros, D., & Rumbach, A. (2022). The Impact of PD Check-In, a Model for Supported Self- Managed Maintenance of Speech on the Quality of Life of People with Parkinson’s Disease: A Phase 1 Study. Brain Sciences, 12(4), 433.

Supporting Research: Reference 3: Ramig, L., Halpern, A., Spielman, J., Fox, C., & Freeman, K. (2018). Speech treatment in Parkinson's disease: randomized controlled trial (RCT). Movement Disorders, 33(11), 1777-1791.

Supporting Research: Reference 4: Levitt, J., & Walker-Batson, D. (2018). The Effects of the "Speak with Intent" Instruction for Individuals With Parkinson's Disease. Journal of Communication Disorders and Assistive Technology, 2 (1), 1-15.

Supporting Research: Reference 5: Bryans, L. A., Palmer, A. D., Anderson, S., Schindler, J., & Graville, D. J. (2021). The impact of Lee Silverman Voice Treatment (LSVT LOUD®) on voice, communication, and participation: Findings from a prospective, longitudinal study. Journal of Communication Disorders, 89, 106031.