Anna Tignor, Tepanta Fossett, Ph.D.
Lee Silverman Voice Treatment and Parkinson’s Disease
Abstract:
Parkinson’s disease is a progressive neurological disorder that affects the nervous
system and parts of the body controlled by these nerves. Hypokinetic dysarthria is
a motor speech disorder characterized by reduced vocal loudness, imprecise articulation,
breathiness, short bursts of speech, irregular pauses, and monotone voice. One well
supported treatment for this type of dysarthria seen in individuals with PD is the
Lee Silverman Voice Treatment (LSVT). LSVT is an intensive four-week program of voice
therapy targeting hypokinetic dysarthria in individuals with PD, with an overall goal
of increasing vocal loudness so these individuals can improve their communication
with conversation partners. Typical speech-language treatment in PD focuses on maintaining
as much communication ability as possible including strategies and exercises to help
with volume and speed of speech, breathing, facial expressions, and articulation.
The purpose of this research investigation is to compare LSVT and typical speech-language
treatment in improving functional communication outcomes for individuals with PD,
or ability to use compensatory strategies to participate fully and competently in
conversations. Results will be investigated through quality-of-life, quantitative,
and perceptual measures.
50 individuals with PD will be randomly assigned to two groups, with one group receiving
LSVT and the other group receiving typical speech-language treatment. The dependent
measures for this investigation will be administered before, during, and after treatment
over a span of four weeks. To measure functional communication, the Voice Handicap
Index (VHI) and the Communicative Effectiveness Survey (CES) will be administered.
These questionnaires allow participants to describe their voice and communication
and the effects these facts have on their lives. Quantitative measures will consist
of measures of vocal loudness obtained from three tasks using a sound pressure level
(in decibels): 1) sustained /a/ phonation, 2) reading of a passage, and 3) connected
speech with a self-chosen monologue. Additional quantitative data will be provided
by measuring articulatory rate, calculated by measuring the length of each syllable
produced and the pause at the end and within words. Perceptual data will be obtained
from the Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) and will provide
information regarding six vocal qualities: 1) overall severity, 2) roughness, 3) breathiness,
4) strain, 5) pitch, and 6) loudness. In conjunction with the quality-of-life measures,
these quantitative and perceptual measures will be identified and used in comparison
among the two groups. Finally, to measure speech intelligibility, the Assessment for
the Intelligibility of Dysarthric Speech will be administered to obtain an overall
severity estimate of dysarthria in the individuals with PD.
It is hypothesized that LSVT will reduce the effects of PD on communication and positively
affect speech intelligibility and vocal quality. Results will have implications for
identifying and forming an effective treatment plan in individuals with PD with an
overall goal of improving functional communication. In this between-subjects research
design, my research proposal targets the efficacy of LSVT in PD. This research will
identify if LSVT, when compared to typical speech- language treatment, results in
significant differences on vocal loudness, phonation, articulatory rate, and functional
communication outcomes in individuals with PD.