Actigraph analysis of diurnal motor fluctuations during dopamine agonist therapy

Generally, clinicians use rating scales or descriptive writing to characterize diurnal changes in motor signs and symptoms in Parkinson's disease (PD); however, these ratings are subjective and are not easily reproducible.

To examine the usefulness of actigraphy as an objective indicator of akinesia by long-term, continuous measurement of limb motor activity (MA), visualize 24-hour circadian profiles of akinesia, and quantitatively detect cabergoline (CBG) efficacy in both hospitalized patients and outpatients with Parkinson's disease.

MA was continuously recorded with a wrist-worn activity monitor (actigraph) in 29 hospitalized PD patients without tremor or abnormal involuntary movements. In another series consisting of 8 outpatients, the response duration of CBG was measured by using averaged actigraphy.

By averaging data gathered every 24 h over several days, it was possible to quantify the circadian patterns of akinesia. These cumulative evaluations of the patients' motor status determined 4 types of akinesia: (1) a wearing-off pattern seen in advanced efficacy stages, (2) stable response, (3) afternoon akinesia, and (4) morning akinesia. Following CBG therapy, the MA increased significantly throughout the daytime, i.e.: by 40% in the morning (8:00 a.m. to 12:00 noon), by 60% in the afternoon (12:00 noon to 6:00 p.m.), and by 60% in the next early morning (from time to get up until 8:00 a.m.).

In averaged motor activity, the charting of cumulative evaluations of motor status revealed the long-acting efficacy of CBG in ameliorating existing motor fluctuations throughout the daytime and even promoting sleep benefit in the next morning. Averaged actigraphy is considered to be useful in the quantitative detection of drug responses to parkinsonian akinesia and its circadian variations. This enables titration of the lowest dose of drugs needed to alleviate akinesia.