Efficacy of LSVT-LOUD Therapy on Voice, Speech, and Quality of Life in Parkinson's Disease

Official title

The Effect of Lee Silverman Voice Therapy-LOUD (LVST-LOUD) Therapy Method on Voice and Speech Skills and Examination of Therapy Experiences in Turkish-Speaking Individuals With Parkinson's Disease

Overview

Parkinson's disease often causes speech and voice impairments, such as reduced vocal loudness and decreased speech intelligibility, which significantly impact the quality of life for patients and their families. The Lee Silverman Voice Therapy-LOUD (LSVT-LOUD) is a specialized, evidence-based speech therapy protocol designed to improve vocal function. This study investigates the effectiveness of the LSVT-LOUD protocol in Turkish-speaking individuals with Parkinson's disease. The research evaluates objective changes in vocal loudness and speech quality, as well as the subjective therapy experiences of participants. By analyzing both clinical outcomes and patient feedback, this study aims to contribute to the clinical application and adaptation of LSVT-LOUD for the Turkish-speaking population

Detailed description

This study implements the standardized Lee Silverman Voice Treatment (LSVT-LOUD) protocol, an intensive intervention focused on the recalibration of vocal effort through motor learning principles. The intervention requires participants to attend individual therapy sessions conducted four times per week over a four-week period, with each session lasting 60 minutes.

The protocol emphasizes high-effort phonation and is structured into the following components:

Daily Tasks: Sustained vowel phonation (maximum duration and stability), pitch range exercises (high-to-low and low-to-high glides), and maximum functional loudness drills using high-effort speech.

Hierarchy Tasks: Systematic progression from word-level to sentence-level and, finally, conversational speech tasks, incorporating high-effort vocal production into increasingly complex linguistic structures.

Carry-over Exercises: Daily practice assignments designed to facilitate the generalization of high-effort speech into activities of daily living and social interactions.

Clinical instruction emphasizes the patient's sensory perception of vocal effort, using acoustic feedback to help participants recalibrate their internal perception of 'loud' versus 'normal' speech. The protocol is conducted in Turkish, adhering to the original LSVT-LOUD methodological requirements while accounting for linguistic nuances of the Turkish language.

Interventions

• Behavioral LSVT-LOUD Therapy
  The LSVT-LOUD protocol is a structured, intensive speech treatment specifically designed for individuals with Parkinson's disease. The intervention follows a standardized format: 4 individual 60-minute sessions per week for 4 consecutive weeks (total of 16 sessions). The core exercises include: Daily Tasks: Sustained phonation (holding 'ah' at a loud, stable pitch), pitch range exercises (high and low), and maximum duration of vowel phonation. Functional Speech Tasks: Practicing high-effort v

Primary outcome measures

• Qualitative Therapy Experience [Time frame: Post-therapy (4 weeks)]
• Vocal Intensity (Loudness) [Time frame: Baseline (pre-therapy), post-therapy (4 weeks), 1-month follow-up, and 3-month follow-up.]
• Acoustic Voice Stability (Jitter and Shimmer) [Time frame: Baseline (pre-therapy), post-therapy (4 weeks), 1-month follow-up, and 3-month follow-up.]
• Fundamental Frequency (F0) [Time frame: Baseline (pre-therapy), post-therapy (4 weeks), 1-month follow-up, and 3-month follow-up.]

Secondary outcome measures (2)

• Voice Handicap Index (VHI) [Time frame: Post-therapy (4 weeks)]
• Parkinson's Disease Questionnaire (PDQ-39) [Time frame: post-therapy (4 weeks)]

Eligibility criteria

Inclusion criteria

Diagnosis: Patients with a confirmed diagnosis of Idiopathic Parkinson's Disease (Hoehn and Yahr stages I-III).

Age: Individuals aged 40-80 years.

Language: Native Turkish speakers.

Cognitive Status: Sufficient cognitive function to participate in therapy (e.g., Mini-Mental State Examination (MMSE) score ≥ 24).

Communication: Presence of voice or speech impairment (e.g., hypophonia, reduced intelligibility) as confirmed by a speech-language pathologist.

Stability: Stable medication regimen for at least 1 month prior to the study initiation.

Exclusion criteria

Neurological Comorbidities: Presence of other significant neurological disorders (e.g., stroke, traumatic brain injury, multiple sclerosis) or active voice disorders (e.g., vocal cord nodules, laryngeal cancer).

Hearing Impairment: Uncorrected hearing loss that would interfere with speech assessment or therapy.

Cognitive Impairment: Diagnosis of dementia or severe cognitive impairment that prevents participation in the intensive LSVT-LOUD protocol.

Recent Surgery: History of laryngeal surgery or deep brain stimulation (DBS) within the last 6 months.

Therapy History: Previous experience with LSVT-LOUD or intensive speech therapy within the past year.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Supportive care

Study locations

Turkey (Türkiye) · 1 center

• Atlas University — Kâğıthane

Identifiers

NCT: NCT07730073 · 61351342/020-220 · 61351342/020-220

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗