Journal
PARKINSONISM & RELATED DISORDERS
Volume 18, Issue 5, Pages 572-577Publisher
ELSEVIER SCI LTD
DOI: 10.1016/j.parkreldis.2012.03.001
Keywords
Gold standard; Accelerometry; FOG; Timed up-and-go task
Categories
Funding
- National Space Biomedical Research Institute
- NASA [NNX09AL14G]
- NIH [5R01DC007658-05]
- NHMRC [1008117]
- University of Sydney
- NASA [110831, NNX09AL14G] Funding Source: Federal RePORTER
Ask authors/readers for more resources
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. (C) 2012 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available