Objective levodopa response in Parkinson's disease: A study within the medical consultation using an RGB-D camera (Kinect®).

Background: Since 1988, one of the most relevant criteria that support diagnosis of Parkinson Disease (PD) is the response to levodopa. Levodopa effect is evaluated using clinical scales such (MDS-UPDRS). Although this approach is informative its assessment is highly subjective. Objectives: quantify the motor response to levodopa in patients with Parkinson's disease using a portable and inexpensive RGB-D camera (Kinect) Methods: 11 PD patients were included. Descriptive analysis were used for clinical variables. Spearman´s rank correlation was used to correlate the age and the gait variables. Wilcoxon matched-pairs signed-rank test was used for the gait variables comparison between ON and OFF states. Results: In ON state PD patients showed increments in global speed [p=0.007], ankle speed [p<0.001], ankle stride length [p=0.001], arm swing speed [p=0.008], and arm swing magnitude [p=0.014], these results slightly changed when the sample was analyzed taking into account the individual behavior of each limb. In comparison with the upper limbs, levodopa response was more uniform in the lower limbs. Conclusion: As expected, in ON state PD patients improve their speed and their limbs range of movement during gait. Levodopa response can be measured within the medical consultation using a RGB-D camera.