Voice improvement following conventional speech therapy combined with singing intervention in people with Parkinson's disease: A three-arm randomised controlled trial

Abstract

Background: Although speech and voice disorders are common in Parkinson's disease (PD), there is insufficient evidence to support the effectiveness of behavioural speech therapies in these patients. Aims: This study aimed to examine the effects of a new tele-rehabilitation program, a combining of conventional speech therapy and singing intervention, on voice deficits in patients with PD. Methods & Procedures: This study was a three-armed, assessor-masked, randomised controlled trial. Thirty-three people with PD were randomly assigned to the combination therapy, conventional speech therapy, or singing intervention group. This study followed the Consolidated Standards of Reporting Trials guidelines for non-pharmacological treatment. Each patient participated in 12 tele-rehabilitation sessions over 4 weeks. The combination therapy group received speech and singing interventions simultaneously (respiratory, speech, voice, and singing exercises). Voice intensity as a primary outcome and the voice handicap index (VHI), maximum frequency range, jitter and shimmer as secondary outcomes were evaluated 1 week before the first intervention session, 1 week after the last intervention session and 3 months after the last evaluation. Outcomes & Results: The results of repeated measures analysis of variance showed a significant main effect of time on all outcomes in all three groups after treatment (p < 0.001). There was a significant group effect for voice intensity (p < 0.001), VHI (p < 0.001), maximum frequency range (p = 0.014) and shimmer (p = 0.001). The combination therapy group demonstrated a significant outperformance in the VHI and shimmer than the speech therapy (p = 0.038) and singing intervention (p < 0.001) groups. The results of this study also indicated that combination therapy group compared to singing intervention group had a larger effect on voice intensity (p < 0.001), shimmer (p < 0.001) and maximum frequency range (p = 0.048). Conclusions & Implication: The results demonstrated that combining speech therapy with a singing intervention delivered through tele-rehabilitation might be more effective in improving voice problems in patients with PD. What this paper adds: What is already known on the subject Parkinson's disease (PD) is a neurological disorder that frequently causes disturbances in speech and voice, which negatively affect patients’ quality of life. Although speech difficulties occur in 90% of patients with PD, evidence-based treatment options for speech and language problems in these patients are limited. Therefore, further studies are required to develop and assess evidence-based treatment programs. What this study adds The findings of this study showed that a combination therapy program including conventional speech therapy approaches and individual singing intervention provided through tele-rehabilitation may have a greater effect on the improvement of voice problems in people with PD compared to speech therapy and singing intervention alone. What are the clinical implications of this work? Tele-rehabilitation combination therapy is an inexpensive and enjoyable behavioural treatment. The advantages of this method are that it is easy to access, appropriate for many stages of voice problems in PD, requires no prior singing training, encourages voice health and self-management and maximises treatment resources available to people with PD. We believe that the results of this study can provide a new clinical basis for treatment of voice disorders in people with PD.