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A comparison of clinical and objective measures of freezing of gait in Parkinson's disease

journal contribution
posted on 29.10.2018, 00:00 by TR Morris, C Cho, V Dilda, JM Shine, SL Naismith, SJG Lewis, Steven MooreSteven Moore
Freezing of gait, a paroxysmal motor block, is common in the latter stages of Parkinson's disease. The current 'gold standard' of assessing the severity of freezing is based on clinical identification (by up to 3 raters) of the number of episodes from video. The aims of this study were to systematically assess this 'gold standard' across multiple Parkinson's disease centers, and to compare these clinical ratings with objective measures derived from lower limb acceleration data. Video recordings were acquired during a timed up-and-go task from 10 Parkinson's disease patients (with a clinical history of freezing) in the 'off' state. Patients were instrumented with accelerometers on the lateral aspect of each shank. Ten experienced clinicians were recruited from four Parkinson's disease centers to independently assess the videos for number and duration of freezing events. The reliability of clinical video assessment for number of freezing events was moderate (intraclass correlation coefficient 0.63). Percent time frozen (cumulative duration of freezing episodes/total duration of the walking task) demonstrated stronger agreement between raters (0.73). Agreement of accelerometry-derived measures of freezing severity with mean clinician ratings was strong for number of episodes (0.78) and very strong for percent time frozen (0.93). The results demonstrate the viability of objective measures of freezing, and that percent time frozen is a more reliable metric of severity than number of freezing events for both clinical and objective measures. The large variability between clinicians suggests that caution should be used when comparing subjective ratings across centers. © 2012 Elsevier Ltd.

History

Volume

18

Issue

5

Start Page

572

End Page

577

Number of Pages

6

eISSN

1873-5126

ISSN

1353-8020

Publisher

Elsevier, UK

Peer Reviewed

Yes

Open Access

No

Acceptance Date

01/03/2012

External Author Affiliations

University of Sydney; Mount Sinai School of Medicine, USA

Author Research Institute

Centre for Intelligent Systems

Era Eligible

Yes

Journal

Parkinsonism and Related Disorders

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