Objective detection of subtle freezing of gait episodes in Parkinson's disease

Freezing of gait (FOG) is a clinically defined phenomenon of Parkinson's disease (PD). Recent evidence suggests that subtle FOG episodes can be elicited in a gait laboratory using suddenly appearing obstacles during treadmill walking. We evaluated which quantitative gait parameters identify suc...

Full description

Saved in:
Bibliographic Details
Published in:Movement disorders 2010-08, Vol.25 (11), p.1684-1693
Main Authors: Delval, Arnaud, Snijders, Anke H., Weerdesteyn, Vivian, Duysens, Jacques E., Defebvre, Luc, Giladi, Nir, Bloem, Bastiaan R.
Format: Article
Language:English
Subjects:
Aged
Analysis of Variance
Biological and medical sciences
Biomechanical Phenomena - physiology
Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases
Exercise Test - methods
fast Fourier transform
Female
festination
Fourier Analysis
freezing of gait
Freezing Reaction, Cataleptic - physiology
frequency analysis
Gait Disorders, Neurologic - diagnosis
Gait Disorders, Neurologic - etiology
Humans
Knee Joint - physiopathology
Male
Medical sciences
Middle Aged
Neurology
Parkinson Disease - complications
Parkinson's disease
ROC Curve
Single-Blind Method
Time Factors
Walking - physiology
wavelets
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Freezing of gait (FOG) is a clinically defined phenomenon of Parkinson's disease (PD). Recent evidence suggests that subtle FOG episodes can be elicited in a gait laboratory using suddenly appearing obstacles during treadmill walking. We evaluated which quantitative gait parameters identify such subtle FOG episodes. We included 10 PD patients with FOG, 10 PD patients without FOG, and 10 controls. Subjects walked on a motorized treadmill while avoiding unexpectedly appearing obstacles. Treadmill walking was videotaped, and FOG episodes were identified by two independent experts. Gait was also analyzed using detailed kinematics. Knee joint signals were processed using time–frequency analysis with combinations of sliding fast Fourier transform and wavelets transform. Twenty FOG episodes occurred during treadmill walking in 5 patients (all with clinically certified FOG), predominantly in relation to obstacle avoidance. FOG was brief when it occurred just before or after obstacle crossing and was characterized by short, rapid steps. Frequency analysis showed a typical qualitative pattern: before the FOG episode an increase in dominant frequency in the 0 to 3 Hz band (festination), followed by decreased power in 0 to 3 Hz band and an increased power in the 3 to 8 Hz band during the FOG episode. This pattern led to an increased FOG index as a qualitative measure. These approaches detected even very brief FOG with acceptable sensitivity (75–83%) and specificity (>95%). We conclude that time–frequency analysis is an appropriate approach to detect brief and subtle FOG episodes. Future work will need to decide whether this approach can support or even replace expert clinical opinion. © 2010 Movement Disorder Society
ISSN:0885-3185
1531-8257
DOI:10.1002/mds.23159