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 (R)) 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 (R) 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 (R) 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 (R) environment, dysarthria severity, and interaction effects were obtained for all outcomes measures. Significant improvements following the LSVT (R) were also noted on the majority of measures. The LSVT (R) 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.