Video-based automated analysis of MDS-UPDRS III parameters in Parkinson disease

BackgroundAmong motor symptoms of Parkinsons disease (PD), including rigidity and resting tremor, bradykinesia is a mandatory feature to define the parkinsonian syndrome. MDS-UPDRS III is the worldwide reference scale to evaluate the parkinsonian motor impairment, especially bradykinesia. However, MDS-UPDRS III constitutes an agent-based score making reproducible measurements and follow-up challenging. ObjectivesUsing a deep learning approach, we developed a tool to compute an objective score of bradykinesia based on the gold-standard MDS-UPDRS III. MethodsIn the Movement Disorder unit of Avicenne University Hospital, we acquired a large database of videos of parkinsonian patients performing MDS-UPDRS III protocols. We applied two deep learning algorithms to detect a two-dimensional (2D) skeleton of the hand composed of 21 predefined points, and transposed it into a three-dimensional (3D) skeleton. ResultsWe developed a 2D and 3D automated analysis tool to study the evolution of several key parameters during the protocol repetitions of the MDS-UPDRS III. Scores from 2D automated analysis showed a significant correlation with gold-standard ratings of MDS-UPDRS III, measured with coefficients of determination for the tapping (0.609) and hand movements (0.701) protocols using decision tree algorithms. The individual correlations of the different parameters measured with MDS-UPDRS III scores carry meaningful information and are consistent with MDS-UPDRS III guidelines. ConclusionWe developed a deep learning-based tool to reliably score and analyze bradykinesia for parkinsonian patients.