Parkinson's Disease: Pilot Single-subject Research Design

Parkinson's disease is a progressive degenerative neurological disease that primarily affects the movements. It includes symptoms such as tremors, muscle rigidity, postural instability, changes in gait and bradykinesia, poor voice quality and errors in speech production. In a review done by de Lau and Breteler (2006), it was reported that an estimated 10 million people in the world (i.e., approximately 0.3% of the world population) and 1% of those above 60 years are found to be affected with Parkinsonism. This study is the Perceptual analysis of voice characteristic of an individual with Parkinson’s disease for a period of six months. The participant aged 61 years is diagnosed as 'Multiple system atrophy – Parkinson’s type', in the year 2019. A comprehensive statistical analysis of speech components such a evaluation of Maximum Phonation Duration (MPD ), s/z ratio, Diadochokinetic syllable rates (DDK) are evaluated every month. Also the individual's voice quality are perceptually analyzed using GRBAS Rating Scale. The study was done for over a period of 6 months i.e from November, 2023 to the April, 2024. On analyzing the results over a period of six months it was observed that there was regression throughout the period. The study shows the distinct patterns of deterioration in vocal characteristics that correlate with the advancement of PD symptoms, including changes in vocal pitch, loudness and articulation.