Treating disordered speech and voice in Parkinson's disease online: A randomized controlled non-inferiority trial

Background: Telerehabilitation may be a feasible solution to the current problems faced by people with Parkinson's disease in accessing speech pathology services. Aim: To investigate the validity and reliability of online delivery of the Lee Silverman Voice Treatment (LSVT®) for the speech and voice disorder associated with Parkinson's disease. Method & Procedures: Thirty-four participants with Parkinson's disease and mild-to-moderate hypokinetic dysarthria took part in the randomized controlled non-inferiority laboratory trial and received the LSVT® in either the online or the face-to-face environment. Online sessions were conducted via two personal computer-based videoconferencing systems with real-time and store-and-forward capabilities operating on a 128 kbit/s Internet connection. Participants were assessed pre- and post-treatment on acoustic measures of mean vocal sound pressure level, phonation time, maximum fundamental frequency range, and perceptual measures of voice, articulatory precision and speech intelligibility. Outcomes & Results: Non-inferiority of the online LSVT® modality was confirmed for the primary outcome measure of mean change in sound pressure level on a monologue task. Additionally, non-significant main effects for the LSVT® environment, dysarthria severity, and interaction effects were obtained for all outcomes measures. Significant improvements following the LSVT® were also noted on the majority of measures. The LSVT® was successfully delivered online, although some networking difficulties were encountered on a few occasions. High participant satisfaction was reported overall. Conclusions & Implications: Online treatment for hypokinetic dysarthria associated with Parkinson's disease appears to be clinically valid and reliable. Suggestions for future research are outlined.