Attention modulation during motor preparation in Parkinsonian freezers: A time-frequency EEG study.
OBJECTIVE
To investigate the cortical integration of attentional stimuli during motor preparation in parkinsonian patients with freezing of gait (FoG, n=12) or without freezing of gait (n=13), and in aged-matched healthy controls (n=13). We hypothesized that interference between attention and action in freezers would be revealed by differences in cortical modulation during this dual task.


METHODS
Attention during step preparation was modulated by means of an auditory oddball discrimination task. EEG oscillations in different frequency bands were measured for the attentional stimulus and the motor stimulus.


RESULTS
Over the 500ms following the sound, low-frequency power increased in all three groups. This was followed by a power decrease in mid-range frequencies after both target and standard sounds in the healthy controls and in the non-FoG group. In contrast, EEG oscillations in the beta band were impaired in the FoG group, who notably failed to display event-related desynchronization after perceiving the sound.


CONCLUSIONS
An attentional stimulus was able to trigger event-related desynchronization before motor preparation in the non-FoG group but not in the FoG group.


CONCLUSIONS
In the FoG group, stimulus discrimination was maintained but the coupling between attention and motor preparation was impaired.
Université de Lille, Lille, France; Troubles cognitifs, dégénératifs et vasculaires, INSERM U1171, France. Electronic address: celine.tard@chru-lille.fr.
Céline
C
Tard
Université de Lille, Lille, France; Troubles cognitifs, dégénératifs et vasculaires, INSERM U1171, France; Service de Neurologie et Pathologie du mouvement, CHRU de Lille, Lille, France.
Kathy
K
Dujardin
Troubles cognitifs, dégénératifs et vasculaires, INSERM U1171, France; Service de Neurophysiologie clinique, CHRU de Lille, Lille, France.
Jean-Louis
JL
Bourriez
Université de Lille, Lille, France.
Behnam
B
Molaee-Ardekani
Université de Lille, Lille, France; Troubles cognitifs, dégénératifs et vasculaires, INSERM U1171, France; Service de Neurophysiologie clinique, CHRU de Lille, Lille, France.
Philippe
P
Derambure
Université de Lille, Lille, France; Troubles cognitifs, dégénératifs et vasculaires, INSERM U1171, France; Service de Neurologie et Pathologie du mouvement, CHRU de Lille, Lille, France.
Luc
L
Defebvre
Université de Lille, Lille, France; Troubles cognitifs, dégénératifs et vasculaires, INSERM U1171, France; Service de Neurophysiologie clinique, CHRU de Lille, Lille, France.
Arnaud
A
Delval
D000161:Acoustic Stimulation / Q000379:methods; D000368:Aged; D059031:Anticipation, Psychological / Q000502:physiology*; D001288:Attention / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D020233:Gait Disorders, Neurologic / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D020734:Parkinsonian Disorders / Q000175:diagnosis / Q000503:physiopathology*; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology*; D011897:Random Allocation; D011930:Reaction Time / Q000502:physiology*
Freezing of gait; Gait initiation; Parkinson’s disease; Pre-cueing paradigm; Stimulus-driven attention