Rjw. Dunnewold et al., QUANTITATIVE ASSESSMENT OF BRADYKINESIA IN PATIENTS WITH PARKINSONS-DISEASE, Journal of neuroscience methods, 74(1), 1997, pp. 107-112
In order to optimize a method for quantitative assessment of bradykine
sia, we evaluated the three-dimensional sources of a movement signal o
f the wrist and influence of tremor on the reliability of bradykinesia
measurements. A total of 33 patients with Parkinson's disease, three
patients with Multiple System Atrophy and 29 healthy controls performe
d a test procedure to measure slowness of movement, consisting of a ta
p rate (TR) test and a movement time (MT) lest. Simultaneously, accele
rometers were mounted on the wrist and mean bi- and tri-axial vectors
were calculated. Thus the acquired means of acceleration were correlat
ed with the commonly used measures of bradykinesia, i.e. tap rate and
movement time. Our results show that bradykinesia is reliably measured
by the evaluation of the mean acceleration of movements, and support
the use of any of the three bi-axial vectors. Compared to the bi-axial
vectors, the tri-axial vector provided no relevant additional informa
tion. Additionally, the presence of a moderate to severe resting tremo
r did not influence the assessment of bradykinesia. Because of the pos
sibility of continuous assessment of bradykinesia this new monitor may
prove to be of great value in pharmacodynamic studies and the longitu
dinal follow-up of patients in drug trials. (C) 1997 Elsevier Science
B.V.