Consciousness states Flashcards
OUTLINE
I. Disorders of consciousness
II. Clinical diagnosis
III. Paraclinical diagnosis
> Active paradigm
> Passive paradigm
> Case report
IV. Treatments
> Pharmacological
> Brain stimulation
Challenges
Comment savoir si qq un est conscient, notamment en présence d’une forte activité cérébrale ?
Etablir une évaluation précise de la douleur/nociception chez les patients UWS ou MCS. NCS = first step
- Awareness evaluation
O/V
Intelligible Words
Vocalization Only
AROUSAL
Sustained Attention Eyes
Open w/o Stim
Eyes Open w/ Stim
MOTOR
Functional Object Use
Object Manipulation
Automatic Movement
I. Disorders of consciousness : Clinical entities
Disorders of consciousness
I. Disorders of consciousness : COMA
No eyes opening
No sign of consciousness
Lasting min 1 hour
I. Disorders of consciousness : Vegetative state/Unresponsive
No sign of consciousness
No environment interaction
No voluntary behavior in response to visual, auditive, tactile and painful stimuli
No language comprehension – no language expression
Wake-sleep cycle
NEW NAME : UNRESPONSIVE WAKEFULLNESS SYNDROME
I. Disorders of consciousness : Minimally conscious state
Limited but clearly discernible evidence of self or environmental awareness.
One or more of the following behaviors:
• Following simple commands.
• Gestural or verbal yes/no responses (regardless of accuracy).
• Intelligible verbalization.
• Purposeful behavior, including movements or affective behaviors that occur in contingent relation to relevant environmental stimuli:
– appropriate smiling
– appropriate vocalizations or gestures
– reaching for objects
– touching or holding objects
– visual pursuit or fixation
Emergence from MCS
• Functional interactive communication
• Functional use of two different objects
I. Disorders of consciousness : MCS +/-
MCS +
Following simple command
MCS -
Pain localisation
Visual pursuit
Accurate smiling or crying
MCS was recently subcategorized based on the complexity of patients’ behaviours: MCS+ describes high-level behavioural responses (i.e., command following, intelligible verbalizations or non-functional communication) and MCS- describes low-level behavioural responses (i.e., visual pursuit, localization of noxious stimulation or contingent behaviour such as appropriate smiling or crying to emotional stimuli)
I. Disorders of consciousness : Where is consciousness in the
brain?
Consciousness # whole brain
Consciousness ≈ frontoparietal
PRECUNEUS
hub in the network
> systematiquement impliqué dans les UWS
> Dans la remission, partie qui se développe
Activité du précuneus
En comparant avec Control > LIS > MCS > UWS = 0
I. Disorders of consciousness : 2 networks
Internal awareness network
ACC
External awarness network
Inferior parietal lobule (AG - SMG)
I. Disorders of consciousness : pain
Besoin d’une nouvelle façon d’évaluer la capacité à ressentir la douleur afin d’ajuster la sedation.
Nociception Coma Scale
Scores corelated with ACC activation
I. Disorders of consciousness : do they hear us ?
Control & MCS : associative areas connected
UWS : nope
II. Clinical diagnosis : misdiagnosis
Threshold btw UWS & MCS
Difference entre Volontaire/voulu et Automatic/Reflexe
En fonction de l’échelle employée, le diagnosis posé (et les traitements associés) peut être différents. D’où l’importance de ces échelles.
Glasgow recovery scale : 24/77 MCS
Coma Recovery Scale - Revised : 45/77 MCS
41% of potential misdiagnosis = patients définis comme non conscients alors qu’ils le sont !
III. Paraclinical diagnosis : active paradigm
fMRI
> Imagining playing tennis / spatial navigation
Communicatrion is possible “YES” “NO”
Activation studies can predict outcome
Metanalysis - Di et al. - 2008
EEG
MMN sur P3
prenom non familier/ propre prenom
> amplitude correle état de conscience
> pas une onde de cosncience car UWS répondent aussi
EMG
easiest
“move the right hand”
PB : always uses language
III. Paraclinical diagnosis : passive paradigm
Aphasia ppl may not be able to understand instructions
=> passive paradigms
Bonne capacité à discerner UWS de MCS ! (74% PET, 56% fMRI prediction outcome)
Default Mode Network
DMN conectivity corelates the degree of consciousness
-> no task, resting state
Vanhaudenhuyse et al, 2010
FDG PET Scan + fMRI
(fluorodeoxyglucose)
Thibaut et al 2012
>> Can predict outcome
TMS/EEG
Wakefulness : complex, long lasting, both hemispheres
→ Integrated information theory