Lee Silverman Voice Treatment effective for most Parkinson’s patients
MedWire News: Lee Silverman Voice Treatment (LSVT) results in significant improvements in sentence intelligibility for most idiopathic Parkinson's disease (PD) patients, show study results.
However, a small percentage of patients do not respond well to the treatment, say the researchers.
Around 89% of patients with idiopathic PD have hypokinetic dysarthria, resulting from a lesion on the substantia nigra. Symptoms include monopitch, slurring of words, hoarseness of speech, short rushes of speech, and reduced intensity
LSVT is an intense behavioral voice treatment developed to combat hypokinetic dysarthria, and has been shown to improve speech intensity in PD patients for up to 2 years. However, its effects on speech intelligibility in these individuals are less clear.
To investigate further, eight individuals (five men, three women) with idiopathic PD, aged 66.3 years on average, underwent LSVT 4 days a week for 4 weeks.
Sentence intelligibility was measured on days 1, 2, and 3 before and 1, 2, and 3 after treatment by recording the participants' speech and then playing the recordings to normal-hearing listeners in a randomized fashion. The percentage of words understood by the listeners was then calculated.
In addition to measurement of intelligibility, the team also recorded changes in overall vocal intensity before and after treatment.
As reported in the Journal of Voice, Michael Cannito (University of Memphis, Tennessee, USA) and colleagues found that mean intelligibility improved significantly from 81.1% before treatment to 85.8% after treatment, independent of days or speakers.
But, not all speakers responded similarly to treatment and when assessed on a person-to-person basis only six of the eight participants exhibited significant improvements in intelligibility after LSVT.
Of the other two patients, one had no change from baseline and one had a decrease in intelligibility.
Overall, voice intensity increased following LVST in most of the patients.
"Present findings support the use of LSVT as a means of increasing intelligibility for speakers with idiopathic PD (in addition to enhancing loudness and voice quality)," write the authors.
"Further study is needed to examine whether the findings will be upheld with a larger sample of speakers with PD and to determine whether a subgroup of PD patients may not exhibit improved intelligibility as a result of treatment," they add.
"Future studies also should examine intelligibility of PD speakers' spontaneous utterances in comparison with sentence reading tasks of the type used in the present research."
By Helen Albert