The primary aim of this pilot study was to evaluate the effects of a novel dysphagia rehabilitation approach: skill training on swallowing in individuals who have dysphagia secondary to Parkinson’s disease. The secondary objective was to assess skill retention following treatment termination. This within-subject study involved 10 patients with Parkinson’s disease who met the inclusionary criteria. All participants underwent two baseline data collection sessions, conducted two weeks apart. Data collected included the water swallow test, Test of Mastication and Swallowing Solids (TOMASS), ultrasound measurement of hyoid movement and cross-sectional area of submental muscles, surface electromyography (sEMG) of submental muscles, and swallowing-related quality of life questionnaire (SWAL-QOL). Patients then underwent 10 sessions over two weeks of skill training therapy using custom-designed sEMG software. The focus of the treatment was producing swallowing tasks with defined and adjustable temporal and amplitude precision. The skill training treatment phase was followed by an immediate post-intervention assessment session and two weeks later by a retention assessment session. All outcome measures were administered at each data collection point. The study consisted of a total of 14 laboratory sessions, conducted over a six-week period per subject. Results revealed significant improvements in swallowing efficiency for liquids, reduced durational parameters on sEMG, such as pre-motor time (PMT), pre-swallow time (PST), and duration of submental muscle contraction. There was a functional carry-over effect seen from dry swallows, which were the focus of training, to water swallows, which were not directly trained. Additionally, improvements in swallowing-related quality of life were demonstrated.
In conclusion, the skill training approach evaluated in this research is able to produce functional, biomechanical, and swallowing-related quality of life improvements in patients with Parkinson’s disease. This indicates the potential effectiveness of this novel approach for dysphagia rehabilitation in this population. However, replication with a larger number of patients with Parkinson’s disease is needed before findings can be generalised to the larger population