Effects of sham-controlled double blind transcranial direct current - - PowerPoint PPT Presentation

▶
effects of sham controlled double blind transcranial
SMART_READER_LITE
LIVE PREVIEW

Effects of sham-controlled double blind transcranial direct current - - PowerPoint PPT Presentation

Aug 30, 2022 146 likes •372 views

Effects of sham-controlled double blind transcranial direct current stimulation in patients with disorders of consciousness THIBAUT Aurore PhD Student Physiotherapist Coma Science Group Cyclotron Research Centre & University &

slide-1
SLIDE 1

www.comascience.org

Effects of sham-controlled double blind transcranial direct current stimulation in patients with disorders of consciousness

THIBAUT Aurore

PhD Student Physiotherapist Coma Science Group Cyclotron Research Centre & University & University Hospital of Liège Belgium

slide-2
SLIDE 2

www.comascience.org

disorders of consciousness | behavioural evaluation | electrophysiology | neuroimaging | methods, ethics & quality of life | perspectives

AIM of the study

Assessing the effect of transcranial direct current stimulation (tDCS) on cognition in patients with disorder of consciousness

In a double blind sham controlled randomized study

Introduction | Materials and Methods | Results | Discussion | Perspectives

slide-3
SLIDE 3

www.comascience.org

Why direct current stimulation?

Introduction | Materials and Methods | Results | Discussion | Perspectives

Stimulation Population Effects Authors Prefrontal cortex Healthy subjects Memory Marshall et al, J Neurosci 2004 Alzheimer’s patients Memory Ferrucci et al, Neurology 2008 Stroke patients Attention Jo et al, Am J Phys Med Rehabil 2009 Aphasic patients Language Baker et al, Stroke 2010

  • Non-invasive
  • Easy to apply
  • Cheap equipment
slide-4
SLIDE 4

www.comascience.org

Methods

  • Direct current
  • 2 mA
  • 20 minutes

Randomised double blind sham controlled

Introduction | Materials and Methods | Results | Discussion | Perspectives

Anode Cathode

slide-5
SLIDE 5

www.comascience.org

Methods

Responder : CRS-R post tDCS > pre-tDCS > sham > pre-sham

Statistics: Stata 10.0 ANOVA Wilcoxon signed-rank test

Giacino, Arch Phys Med Rehabil 2004 Stata 10.0 (StataCorp. 2007. Stata Statistical Software: Release 10. College Station, TX: StataCorp LP)

Introduction | Materials and Methods | Results | Discussion | Perspectives

CRS-R CRS-R CRS-R CRS-R tDCS tDCS 20’ 20’ 24h

slide-6
SLIDE 6

www.comascience.org

Population

  • 55 patients (16 women)
  • 25 VS/UWS, 30 MCS
  • aged 43 ± 18 y
  • 25 traumatic / 30 non-traumatic
  • 20 acute / 35 chronic (>3 months post insult)

Introduction | Materials and Methods | Results | Discussion | Perspectives

slide-7
SLIDE 7

www.comascience.org

Group data (n=55)

* *

N=55 17 responders

  • 2 UWS; acute
  • 15 MCS;

7acute/8chronic

Introduction | Materials and Methods | Results | Discussion | Perspectives

PRE POST PRE POST tDCS

sham CRS-R total scores

slide-8
SLIDE 8

www.comascience.org

Group data (n=55)

* *

17 responders

  • 2 UWS; acute
  • 15 MCS;

7acute/8chronic

Introduction | Materials and Methods | Results | Discussion | Perspectives

PRE POST PRE POST tDCS

sham CRS-R mean scores

slide-9
SLIDE 9

www.comascience.org

UWS/UV vs MCS

VS/UWS (n=25) MCS (n=30) *

Introduction | Materials and Methods | Results | Discussion | Perspectives

PRE POST PRE POST tDCS

tDCS

*

CRS-R mean scores

slide-10
SLIDE 10

www.comascience.org

Responders: audition subscale

* *

Introduction | Materials and Methods | Results | Discussion | Perspectives

PRE POST PRE POST tDCS

sham

Consistent movment to command Reproducible movment to command Localisation of sounds Auditory sartle None

slide-11
SLIDE 11

www.comascience.org

Responders: motor subscale

Functional use of objects Automatic motor reaction Object manipulation Localization of noxious stimulation Flexion withdrawal Abnormal posturing None

* *

Introduction | Materials and Methods | Results | Discussion | Perspectives

PRE POST PRE POST tDCS

sham

slide-12
SLIDE 12

www.comascience.org

Responders: communication

* *

Functional communication Intentionnal communication None

Introduction | Materials and Methods | Results | Discussion | Perspectives

PRE POST PRE POST tDCS

sham

slide-13
SLIDE 13

www.comascience.org

tDCS presumed mode of action

Short term effects

Modification of neuronal excitability (action potential)

Long term effects

Action on opening of ion channels (Na+, Ca2+) Increase NMDA receptors excitability improve neuron excitability

Nitsche et al., J Physiol 2000 Nitsche et al., Neuroscientist 2010

Introduction | Materials and Methods | Results | Discussion | Perspectives

slide-14
SLIDE 14

www.comascience.org

Neuroimagery

Prefrontal stimulation

  • Improvement of DMN connectivity (MRI)
  • Increase of regional electrical activity in the PF and

AC cortexes (EEG) ( ß and δ/θ)

Motor stimulation

  • rCBF increase in the left M1, right prefrontal cortex,

right S1 (PET-scan)

  • Functional connectivity increased within premotor,

motor and sensorimotor areas (EEG)

  • Introduction | Materials and Methods | Results | Discussion | Perspectives

Keeser et al., J Neurosci, 2011 Keeser et al., Neuroimage, 2011 Lang et al., Eur J Neurosci, 2005 Polania, Nitsche and Paulus, HBM, 2010

slide-15
SLIDE 15

www.comascience.org

disorders of consciousness | behavioural evaluation | electrophysiology | neuroimaging | methods, ethics & quality of life | perspectives

tDCS – advantages

DBS and Amantadine improve cognitive functions of patients with disorder of consciousess But invasive and pharmacological tDCS improve cognition of patients in minimally conscious state without risk of brain damage or seizure

Schiff et al., Nature 2008 Giacino et al., New Eng J Med, 2012 Thibaut et al., in prep

Introduction | Materials and Methods | Results | Discussion | Perspectives

slide-16
SLIDE 16

www.comascience.org

tDCS critisisms

  • Short term effect
  • Moderate clinical changes
  • Superficial effect
  • Improve electrode position

Limitations:

Introduction | Materials and Methods | Results | Discussion | Perspectives

slide-17
SLIDE 17

www.comascience.org

tDCS – long term

Effects last ± 90 minutes

  • Short improvement
  • Back to initial state

Hummel et al., Lancet 2006 Antal et al., J Pain Symptom Manage 2010

Daily stimulations (5days) improvement and extension

  • f benefits

Introduction | Materials and Methods | Results | Discussion | Perspectives

slide-18
SLIDE 18

www.comascience.org

tDCS – long term

Introduction | Materials and Methods | Results | Discussion | Perspectives

Prospective, randomized, controlled and double-blind study

1 week 1 week

slide-19
SLIDE 19

www.comascience.org

tDCS - M1

Cognitive effects + Motor effects ?

Lang et al., 2004 Bohannon and Smith, 1987

Parameters:

2 mA – 20 min Anode: M1 Cathode: supraorbicular controlateral cortex

  • 1. Behavioral

assessments: CRS-R & Ashworth

  • 2. TMS: MEP &

motor threshold

Introduction | Materials and Methods | Results | Discussion | Perspectives

slide-20
SLIDE 20

www.comascience.org

tDCS – M1

Introduction | Materials and Methods | Results | Discussion | Perspectives

slide-21
SLIDE 21

www.comascience.org

tDCS – neurophysiology

  • 1. Comparison of the results with:
  • cortical lesions (MRI)
  • cerebral metabolism (PET-scan)

Stimulation of preserved or damaged cortex?

  • 2. EEG brefore and after tDCS

Better understanding of neurophysiological effect of tDCS

Introduction | Materials and Methods | Results | Discussion | Perspectives

slide-22
SLIDE 22

www.comascience.org

Conclusion

tDCS improves cognition in minimally conscious state patients both acute and chronic; traumatic and non traumatic

Introduction | Materials and Methods | Results | Discussion | Perspectives

Future studies: 1. long term tDCS

  • 2. tDCS on M1
  • 3. neurophysiological effects