BACKGROUND: There is growing interest in developing inexpensive and objective motor fluctuation evaluation methods for Parkinson's disease (PD). OBJECTIVES: We aim to compare activity level in the off state, on state, and dyskinetic periods as evaluated either by a physician during a levodopa challenge or by a 72-hr on-off diary self-evaluation in the ambulatory setting. Finally, the effect of daily activities on motor activity in PD and healthy controls was further explored. METHODS: The study was conducted in three consecutive phases. For phase I, in which the on state, off state, and dyskinesia were evaluated using actigraphy, recordings were made during standard acute levodopa challenge in nine dyskinetic PD patients. For phase II, a different set of 16 dyskinetic PD patients was monitored in the ambulatory setting for 72 consecutive hours by actigraphy and a standardized on-off diary. For phase III, 62 PD patients and 14 age- and sex-matched healthy controls wore an actigraph and completed a daily activities diary for 7 days. RESULTS: No differences in activity level between on state and off state during the acute levodopa challenge (phase I) or the 72-hr ambulatory period (phase II) were found. Activity during dyskinesia periods was significantly higher than during on state periods without dyskinesia (p < .01). During the third phase, dyskinetic PD patients and healthy controls showed higher actigraphy-measured activity as compared to de novo, stable, or fluctuating PD (p < .0001), which remained unaltered by daily activities performed during the study period. Tremor UPDRS scores did not correlate with activity level. CONCLUSIONS: These results confirm the lack of specificity of simple wrist-worn actigraphy and further suggest it may be suitable for dyskinesia assessment but not for on state and off state evaluation.
BACKGROUND: There is growing interest in developing inexpensive and objective motor fluctuation evaluation methods for Parkinson's disease (PD). OBJECTIVES: We aim to compare activity level in the off state, on state, and dyskinetic periods as evaluated either by a physician during a levodopa challenge or by a 72-hr on-off diary self-evaluation in the ambulatory setting. Finally, the effect of daily activities on motor activity in PD and healthy controls was further explored. METHODS: The study was conducted in three consecutive phases. For phase I, in which the on state, off state, and dyskinesia were evaluated using actigraphy, recordings were made during standard acute levodopa challenge in nine dyskinetic PDpatients. For phase II, a different set of 16 dyskinetic PDpatients was monitored in the ambulatory setting for 72 consecutive hours by actigraphy and a standardized on-off diary. For phase III, 62 PDpatients and 14 age- and sex-matched healthy controls wore an actigraph and completed a daily activities diary for 7 days. RESULTS: No differences in activity level between on state and off state during the acute levodopa challenge (phase I) or the 72-hr ambulatory period (phase II) were found. Activity during dyskinesia periods was significantly higher than during on state periods without dyskinesia (p < .01). During the third phase, dyskinetic PDpatients and healthy controls showed higher actigraphy-measured activity as compared to de novo, stable, or fluctuating PD (p < .0001), which remained unaltered by daily activities performed during the study period. Tremor UPDRS scores did not correlate with activity level. CONCLUSIONS: These results confirm the lack of specificity of simple wrist-worn actigraphy and further suggest it may be suitable for dyskinesia assessment but not for on state and off state evaluation.