Effects of an Extended Version of the Lee Silverman Voice Treatment on Voice and Speech in Parkinson's Disease.

Purpose The present study examined vocal SPL, voice handicap, and speech characteristics in Parkinson’s disease (PD) following an extended version of the Lee Silverman Voice Treatment (LSVT), to help determine whether current treatment dosages can be altered without compromising clinical outcomes. Method Twelve participants with idiopathic PD received the extended treatment version (LSVT-X), similar to LSVT except that it was administered twice a week in 1-hr sessions over 8 weeks and required substantially more home practice. Recordings were made in a sound-treated booth immediately before and after treatment, and again 6 months later. Vocal SPL was measured for 4 different tasks and compared with data from a previous study, in which participants with PD received traditional LSVT 4 times a week for 4 weeks. Listener ratings were conducted with audio samples from both studies, using sentence pairs from a standard passage. LSVT-X participants completed the Voice Handicap Index (VHI) before each set of reco...