Persistent Vegetative State Flashcards
Wakefulness
Ability to have basic reflexes such as open eyes, cough, swallow, suck
Awareness
Ability to carry out complex though processes
Seat of consciousness
Lateral Prefrontal cortex
Posterior Parietal cortex
Pontine tegmentum
Controls sleep states + levels of arousal and vigilance
Disconnection causes disorders of consciousness
Global workshop theory
Integrate all senses into a single picture and filter out conflicting information
15 GCS
Alert
12 GCS
Verbal stimuli
8 GCS
Painful stimuli
3 GCS
Unresponsive
Levels of consciousness
AVPU
Ascending reticular activating system (ARAS)
Important for alerting or arousal (wakefulness/awareness)
Involve number of structures in rostral brain stem tegmentum, the diencephalon, and projections to cerebral cortex
Centres for sleep
Mainly in preoptic region of hypothalamus
Disorders of consciousness
Comatose- asleep + unconscious
Vegetative- awake and unconscious
Minimally conscious state- awake and some consciousness
Comatose state
State of complete unresponsiveness
Patient lies with eyes closed + can’t be aroused to respond appropriately to any stimuli
Lasts few weeks, rarely longer than month
Stupor
Similar to coma but will respond to strong stimuli
Locked in syndrome
Unresponsiveness
Patient lies with eyes closed + can’t be aroused to respond to stimuli
BUT patient retains eye movement + are fully conscious
Locked in syndrome cause
Injury (trauma, ischaemia) to ventral pons
–> interruption to corticospinal + corticobulbar tracts –> quadriplegia + anarthrua
Guillain-Barre syndrome or MND
Locked in syndrome communication
E-tran frame
Brain computer interface
Akinetic mutism
Condition of apparent alertness along with lack of almost all motor functions including speech, gestures and facial expression
Vegetative state/ Unresponsive Wakefulness syndrome
Spontaneous eye-opening signalling wakefulness, but no evidence of purposeful behaviour suggesting awareness of self or environment
No purposeful behaviours when exposed to stimuli- visual, auditory, tactile, noxious, no language comprehension ore expression
Persistent vegetative state
Vegetative state persisting for at least 1 month after TBI or non-TBI
Permanent vegetative state
Persisting at least 12 months after TBI
Persisting for at least 3 months after non-traumatic causes
Minimally conscious state
Condition of severely altered consciousness where definite, but often subtle and inconsistent, behavioural evidence of self or environmental awareness Yes or no simple Follow simple commands Smile etc Often after coma or VGS
Confusional state
Interactive communication
Amnesia/condfusion
Hypokinetic or agitated
Labile behaviour
Post-confusional state
Resolution in amnesia/confusion
Cognitive impairments in higher levels- attention, memory retrieval, executive functioning
Deficits in self awareness
Functional independence in daily self care
Poor prognosis
Absent brain stem reflexes
More favourable prognosis
Return of speech
Spontaneous eye movements that can track objects
Normal resting tone
Ability to follow commands
Auditory event-related potential
Assessing consciousness
Aim to identify a mismatch negativity (100-250ms after auditory change)
Aim to identify a P300- BUT absent in 10-20% of healthy individuals
PET
Use radioactive FDG to see increase glucose uptake–> brain activity
Blood oxygenation level dependent
fMRI imaging
Difference between oxyHb and deoxyHb
Amantidine
Weak NMDA receptor agonist + blocks dopaminergic reuptake
100-200mg twice daily over 4 weeks
Zolpidem
Indirect GABAa receptor agonist
Half life 2.4 hours
Is an insomnia drug
Mimics inhibition of striatum on GPi (had been lost)–> increase in thalamic excitatory influence on prefrontal cortices
Vagal nerve stimulation
Future treatment
