Assessing disordered speech and voice in Parkinson's disease: a telerehabilitation application

Background: Patients with Parkinson's disease face numerous access barriers to speech pathology services for appropriate assessment and treatment. Telerehabilitation is a possible solution to this problem, whereby rehabilitation services may be delivered to the patient at a distance, via telecommunication and information technologies. A number of studies have demonstrated the capacity of telerehabilitation to provide reliable and valid assessments of speech, voice and language. However, no studies have specifically focused on assessing patients with Parkinson's disease. Aims: To investigate the validity and reliability of a telerehabilitation application for assessing the speech and voice disorder associated with Parkinson's disease. Methods & Procedures: Sixty-one participants with Parkinson's disease and hypokinetic dysarthria were simultaneously assessed in an online and face-to-face environment by two speech-language pathologists. The assessment protocol included perceptual measures of voice and oromotor function, articulatory precision, speech intelligibility, and acoustic measures of vocal sound pressure level, phonation time and pitch range. Online assessments were conducted via a personal computer-based videoconferencing system with store-and-forward capabilities, operating on a 128 kbit/s Internet connection. The level of agreement between the online and face-to-face ratings was determined using several different analyses, depending on the parameter. These included per cent close agreement, quadratic weighted Kappa, and the Bland and Altman limits of agreement. Outcomes & Results: Per cent close agreement between the two environments was within a predetermined clinical criterion of 80% agreement for all voice and oromotor parameters, articulatory precision and speech intelligibility in conversation. Levels of agreement between the environments, based on quadratic weighted Kappa, ranged from poor to good for vocal parameters and from fair to very good for oromotor parameters. Bland and Altman limits of agreement analyses revealed comparability between online and face-to-face environments for vocal sound pressure level, phonation time, pitch range, sentence intelligibility and communication efficiency in reading. Intra- and inter-rater reliability scores for all tasks were comparable between the online and face-to-face environments. Conclusions & Implications: For the majority of parameters, comparable levels of agreement were achieved between the two environments. Online assessment of disordered speech and voice in Parkinson's disease appears to be valid and reliable. The telerehabilitation application described in this study provides evidence for the delivery of online assessment for the dysarthric speech disorder associated with Parkinson's disease.