Ambulatory quantitative assessment of body position, bradykinesia, and hypokinesia in Parkinson's disease.

We used ambulatory monitoring to quantify body position, bradykinesia, and hypokinesia simultaneously in 50 patients with Parkinson's disease (PD) and 43 healthy elderly during the diurnal period. Reliable automatic detection of three defined body positions proved possible. As compared with controls, PD patients spent less time upright and more time during the day lying down, which correlated well with the self-reported time spent lying down. PD patients had significantly lower mean values of extremity acceleration and higher mean values of immobility than controls. The objective measures of bradykinesia and hypokinesia showed only a modest or no relation to the semiquantitative subjective Unified Parkinson's Disease Rating Scale (UPDRS) motor scores, which most likely was due to differences between the methods. In contrast to bradykinesia measures, hypokinesia measures showed clear sex differences in both patients and controls. Over time, trunk and arm movements occurred more frequently in women than in men. Our ambulatory monitoring assessment disclosed clinically relevant information about the mobility profile and offers a way to quantify cardinal movement features simultaneously in PD patients throughout the day.