title: Quantitative assessment of daytime motor activity provides a responsive measure of functional decline in patients with Huntington's disease.
abstract: Voluntary motor impairment is a functionally important aspect of Huntington's disease (HD). Therefore, quantitative assessment of disturbed voluntary movement might be important in follow-up. We investigated the relation between quantitatively assessed daytime motor activity and symptom severity in HD and evaluated whether assessment of daytime motor activity is a responsive measure in the follow-up of patients. Sixty-four consecutive HD patients and 67 age- and sex-matched healthy controls were studied. Daytime motor activity was recorded using a wrist-worn activity monitor that counts all movements during a period of five consecutive days. Patients were rated clinically for voluntary motor impairment, dyskinesias, posture & gait, depression, cognitive impairment and functional capacity. Follow-up was available from 40 patients (mean follow-up 2.0 years) and 29 controls (mean follow-up 5.9 years). Despite chorea, patients had less daytime motor activity than controls (P < 0.005). This hypokinesia correlated with impaired voluntary movements (r = 0.37; P < 0.01), disturbed posture & gait (r = 0.38; P < 0.005) and especially with reduced functional capacity (r = 0.51; P < 0.0005). During follow-up, hypokinesia remained unchanged in clinically stable patients, but became worse in those whose functional disability progressed (P < 0.005). Hypokinesia seems a core symptom of HD which is related to functional capacity. Actimetric assessment of hypokinesia is responsive to disease progression and can be used as an objective tool for follow-up.
authors.affiliation: Department of Neurology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands. j.p.p.van_vugt@lumc.nl
authors.forename: J P
authors.initials: JP
authors.lastname: van Vugt
authors.forename: S
authors.initials: S
authors.lastname: Siesling
authors.forename: K K
authors.initials: KK
authors.lastname: Piet
authors.forename: A H
authors.initials: AH
authors.lastname: Zwinderman
authors.forename: H A
authors.initials: HA
authors.lastname: Middelkoop
authors.forename: J J
authors.initials: JJ
authors.lastname: van Hilten
authors.forename: R A
authors.initials: RA
authors.lastname: Roos
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002940:Circadian Rhythm; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006816:Huntington Disease / Q000150:complications* / Q000503:physiopathology*; D018476:Hypokinesia / Q000209:etiology* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000379:methods*; D009043:Motor Activity; D011237:Predictive Value of Tests