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Aurore THIBAUT, PhD Coma Science Group, GIGA Research, Cyclotron Research Centre & Neurology Department University & University Hospital of Liège
EAN, Berlin, June 20th, 2015
Brain plasticity after implanted drop foot stimulator in chronic stroke
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Workshop Ottobock Stimulation électrique fonctionnelle
implantée chez le patient hémiplégique
External control unit Microcontroller & transmitter
4-channels nerve stimulator Peroneal nerve
Drop foot stimulator
Receptor
Heel switch
Introduction | Protocol | Clinics | PET-scan | HD-EEG | Conclusion
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disorders of consciousness | behavioural evaluation | electrophysiology | neuroimaging | methods, ethics & quality of life | perspectives
Methods
• Chronic stroke patients with drop foot
• Rehazenter Lux (clinical tests) & ULg Be (neuroimaging - EEG – PET – MRI)
• 21 patients included, 7 drop-out (stimulator issue)
• 14 completed the study (5 wo, age: 47±12y, time since insult: 2±1y, 7 lesion on the left)
Clinical
tests Surgery EEG-
PET-MRI Activation Clinical
tests
Clinical tests
Clinical tests EEG-
PET-MRI
Clinical tests
-3 -2 -1 0 3 6 12 24 months
Introduction | Protocol | Clinics | PET-scan | HD-EEG | Conclusion
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Clinical improvement
M -1 M +12
Introduction | Protocol | Clinics | PET-scan | HD-EEG | Conclusion
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PET-scan: Analyses
18FGD-PET-scan at rest
Pre-post : n=14 – right stroke: n=7; left stroke: n=7
7 patients with right lesion were flipped
all patients: lesion on the left hemisphere
Normalization with « flipped template »
Smoothing at 12 mm
Introduction | Protocol | Clinics | PET-scan | HD-EEG | Conclusion
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Results: single subject
Lesion on the left
hypo before stim improvement
DA
CS
SC
0.05 uncorr
Introduction | Protocol | Clinics | PET-scan | HD-EEG | Conclusion
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Results: single subject
Lesion on the right
BD
JR
SV
0.05 uncorr
hypo before stim improvement
Introduction | Protocol | Clinics | PET-scan | HD-EEG | Conclusion
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Results: group
Hypometabolic areas
before activation 1 year later
0.05 FWE
Motor & premotor Prefrontal & caudate
Motor & premotor Prefrontal & caudate
Introduction | Protocol | Clinics | PET-scan | HD-EEG | Conclusion
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Results: group
Increase - motor areas
left&right - Left prefrontal No decrease
Recovery uncorr 0.01
Recovery uncorr 0.001
Introduction | Protocol | Clinics | PET-scan | HD-EEG | Conclusion
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Results: group
0
20
40
60
80
100
120
healthy side
0
20
40
60
80
100
120
damaged side
before 1year later
Brain metabolism in premotor cortex (B6)
before 1year later
Introduction | Protocol | Clinics | PET-scan | HD-EEG | Conclusion
% o
f norm
al bra
in m
eta
bolism
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Analyses
• Power spectrum (delta, theta, alpha beta)
• Entropy • Phase lag index
Motor area
• High density (256 electrodes) • Resting state for 30 min, EO
Introduction | Protocol | Clinics | PET-scan | HD-EEG | Conclusion
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Results: single subject (right stroke)
Motor cortex delta alpha
1st exam 2nd exam difference
beta
alp
ha
t
heta
delta
Introduction | Protocol | Clinics | PET-scan | HD-EEG | Conclusion
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Results: group
n=9 Motor area Data flipped Left lesion
1st exam 2nd exam 1st ≠ 2nd
Introduction | Protocol | Clinics | PET-scan | HD-EEG | Conclusion
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Conclusion
Clinical improvements correlates
• brain metabolism (PET-scan) in motor areas
(damaged & contralateral hemisphere)
• cortical activity (EEG) in motor area
(damaged hemisphere)
Plasticity of the damaged area in chronic stroke patients
Introduction | Protocol | Clinics | PET-scan | HD-EEG | Conclusion
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Thank you!