INTRODUCTION: Timed performance tests were introduced to overcome the disadvantages of subjective evaluation of bradykinesia in Parkinson's disease (PD). We aimed to verify their discriminative properties and compare them with the motion capture analysis of finger tapping. METHODS: We included 22 PD patients (10 M, 12 F), mean age 64 (range 48-82) yrs, Hoehn & Yahr stage 2 (1-2.5) and 22 (10 M, 12 F) normal controls, mean age 66 (41-82) yrs. The key tapping subtest of the Halstead-Reitan battery, the Purdue Pegboard test, and the Bradykinesia-Akinesia Incoordination (BRAIN) test were performed according to the test manuals. The finger tapping subtest of the UPDRS-III, item 23 was recorded using a contactless 3D motion capture system Optitrack-V120. Average frequency (AvgFrq), maximum opening velocity (MaxOpV) and amplitude decrement (AmpDec) were computed and simultaneous video recordings of finger tapping were rated by two experts. RESULTS: The AmpDec and MaxOpV motion capture measures best differentiated between PD patients and controls (AUC = 0.87 and 0.81). Of the instrumental tests, only the Purdue Pegboard attained significance in differentiating PD patients from controls (AUC = 0.80). In PD patients, MaxOpV correlated with the finger tapping ratings and BRAIN test, and AvgFrq correlated with the BRAIN and Halstead-Reitan test scores. Moreover, correlations were found between the Purdue Pegboard and finger tapping ratings. CONCLUSIONS: Contactless 3D motion capture of finger tapping allowed an independent analysis of individual components of bradykinesia, demonstrating the amplitude decrement and maximum opening velocity as the most powerful discriminators between PD patients and controls.

Dept of Biomedical Informatics Czech Technical University Prague Faculty of Biomedical Engineering Sítná sq 3105 CZ 272 01 Kladno Czech Republic

Dept of Neurology and Center of Clinical Neuroscience Charles University Prague 1st Faculty of Medicine and General University Hospital Kateřinská 30 CZ 120 00 Prague Czech Republic

Dept of Neurology Charles University Prague 2nd Faculty of Medicine and Motol University Hospital 5 Úvalu 84 CZ 150 06 Prague Czech Republic