Persistent vegetative state Flashcards
What is the difference between psychological unconsciousness & neurologic unconsciousness [2]
Psychological unconsciousness refers to a state of unawareness or repressed ideas.
Neurologic unconsciousness is paralytic coma.
Important brain structures for arousal/sleep? [3] update !!
Ascending reticular activating system (ARAS): Important for alerting or arousal
Hypothalamus
Circadian clock
Suprachiasmatic nucleus (SCN) – promote arousal.
Which nuclei at the hypothalamus are important with sleep / arousal? [2]
State if they promote sleep or arousal [2]
Tuberomammillary nucleus (TMN) – promote arousal.
Ventrolateral preoptic nucleus (VLPO) – promotes sleep
Which part of the ARAS influences sleep / arousal? [3]
rostral brainstem tegmentum (i.e. pontine tegmentum).
via diencephalon (i.e. thalamus).
projections to the cerebral cortex (i.e. Lateral prefrontal cortex).
Which scales can you use to distinguish consciousness? [2]
Glasgow Coma Scale (GCS)
Loss of consciousness (LOC)
What is the prognosis of coma patients? [1]
A third of coma patients die within one month.
outcome of tbi
What are the 3 main categories of the levels of conciousness [3]
1 Comatose state (asleep and unconscious)
2 Vegetative state (Unresponsive Wakeful Syndrome)
(awake and unconscious)
3 Minimally conscious state (awake and some consciousness)
What is the minimum duration of loss of conciousnesss would severe TBI exhbit? [1]
24 hrs
State the scores for GCS and LOC that would be classified as
Mild
Moderate
Severe
Exam qs
GCS:
* Mild: 13-15
* Moderate: 9-12
* Severe: 3-8
LOC:
* Mild: 0-30min
* Moderate: 30min - less than24hrs
* Severe: >24 hrs
Define comatose state
A state of complete unresponsiveness in which patient lies with eyes closed and cannot be aroused to respond appropriately to any stimuli.
What is the difference betwen comatose state and deep sleep or general anaesthesia? [2]
Deep sleep: requires REM
General anaesthesia: requires anaesthetics
Coma generally a transitional state which last [], and rarely longer than []
Coma generally a transitional state which last a few weeks, and rarely longer than 1 month
Define locked-in syndrome [1]
A state of unresponsiveness in which patient lies with eyes closed and cannot be aroused to respond appropriately to any stimuli. However, patient retains eye movement and are fully conscious
Where in the brain does locked-in syndrome occur because of injury to? [1]
Which tracts are effected if this area is damaged? [2]
ventral pons
causing interruption to corticospinal and corticobulbar tracts
Name two diseases that can cause locked-in syndrome [2]
- Severe case of Guillain-Barre syndrome (autoimmune disorder which immune system attacks healthy neurones)
- motor neurone disease can cause de-efferentation.
Define akinetic mutism [1]
Which areas of the brain are effected with akinetic mutism? [3]
A condition of apparent alertness along with a lack of almost all motor functions including speech, gestures and facial expression.
**Frontal lobe** (supplementary motor area, cingulate gyrus). **Basal ganglia** (caudate, putamen/globus pallidus). **Mesencephalothalamic** regions (midbrain-thalamus).
Define vegetative state / unresponsive wakefullness syndrome [1]
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 or noxious, and no language comprehension or expression.
Where does damage occur in brain if create decoticate or decerebrate damage? [2]
Decorticate (Damage above red nucleus): arms adducted and flexed, legs internally rotated and plantar flexed
Decerebrate (Damage below red nucleus): arms adducted and extended, legs stiffly extended and plantar flexed: Between the vestibular nuclei and red nuclei
Whats the difference between persistent and permanent vegetative state?
Persistent vegetative state:
* Vegetative state persisting for at least 1 month after TBI or non-TBI.
Permanent vegetative state:
* Vegetative state persisting for at least 12 months after traumatic injury.
* Vegetative state persisting for at least 3 months after non-traumatic causes (e.g. anoxic/hypoxia or others).
How long does a vegetative state need to persist before it is classified as permenent vegetative state after brain injury? [1]
12 months
Define minimally conscious state (MCS) [1]
Name three characteristics [3]
Condition of severely altered consciousness in which there is definite, but often subtle and inconsistent, behavioural evidence of self or environmental awareness.
E.g.
* Recognise verbal or gestural ‘yes or no’ responses.
* Follow simple commands.
* Provide purposeful movements (e.g. smile, raise a limb,
use objects (e.g. hairbrush) in a consistent manner).
State 4 characteristics of a confusional state [4]
- Interactive communication.
- Amnesia/confusion (weeks – months).
- Hypokinetic or agitated.
- Labile behaviour (e.g. rapid & exaggerated mood changes- laughing/crying).
State 4 characteristics of post-confusional state
- Resolution in amnesia/confusion (months to years).
- Cognitive impairments in higher levels of attention, memory retrieval, and executive functioning.
- Deficits in self-awareness, social awareness, behavioural and emotional regulation.
- Achieve functional independence in daily self care.
What would 4 things would suggest a more favourable prognosis? [4]
Favourable diagnosis if:
* Ability to follow commands.
* Return of speech (even if incomprehensible).
* Normal resting muscle tone.
* Spontaneous eye movements that can track objects.
Even if emerge from coma/vegetative state, there will be physical, intellectual and psychological problems for life.
In UK, vast majority of PVS patients continue to receive []
Cost £[] per PVS patient/year to care.
In UK, vast majority of PVS patients continue to receive (clinically assisted nutrition and hydration (CANH)
Cost £90,000 per PVS patient/year to care.
What is the percentage rate of recovery from:
<6months of persistent vegetative state? [1]
1 year of persistent vegetative state? [1]
3 years of persistent vegetative state? [1]
Exam q!
What is the percentage rate of recovery from:
<6months of persistent vegetative state: 40%
1 year of persistent vegetative state: 10%
3 years of persistent vegetative state: 5%
exam q
Describe the mechanism of assessing consciousness (Auditory stimulation) using Auditory event-related potential (AERP)
Aim to identify a mismatch negativity (MMN, a negative component appearing in the primary auditory and prefrontal cortices around 100-250 ms after an auditory change in a monotonous sequence of sounds (e.g. an oddball paradigm).
Aim to identify a P300 (a positive component appearing in the primary auditory and prefrontal cortices around 300 ms after an auditory change in a monotonous sequence of sounds (e.g. an oddball paradigm).
Which imaging modalities could you use to assess consciousness? [2]
Stimulation (e.g. auditory, tactile, visual) could carried out on the patient during imaging.
PET scan
Blood oxygenation level dependent (BOLD) fMRI
What is the aim of sensory stimulation? [1]
What sensory treatment could you use as treatment? [5]
Does it work? [1]
Aim:
* To avoid sensory deprivation and to provide an enriched environment to promote neural plasticity (axonal growth, dendritic branching, synaptogenesis)
* increase responsiveness.
Audio (e.g. music, voices of family & friends)
Tactile (e.g. massage, feather, sandpaper)
Visual (e.g. snow globe, blinking light)
Taste (e.g. spices onto tongue, ice pop)
Olfactory (e.g. cologne, vinegar
Remains controversial on its effectiveness, but cheap and simple, so not refuted.
PVS treatment
Name a drug and describe MoA that may help to recover [3]
Amantadine
* NMDA receptor antagonist and block dopaminergic reuptake
* Improves functional recovery rate
PVS treatment
Name another drug and describe MoA that may help to recover [3]
What is this drug usually given for treatment for? [1]
Zolpidem
* Indirect GABAA receptor agonist
* Usually
* Causes patient to become awake, but short acting and return to vegetative state
What is the hypothesis for zolpidem treatment?
Loss of active inhibition from striatum allows GPi to tonically inhibit thalamus and pedunculopontine nucleus, so thalamocortical overactivity
Future treatment for PVS? [1]
Vagal nerve stimulation:
Which part of the brain may vagal nerve stimulation activate in treatment of PVS? [2]
activates the
thalamo-cortical network (?) - pontine tegmentum (?)
Tuberomammillary nucleus increases arousal by secreting which of the following
5-HT
Histamines
Orexins
Noradrenaline
GABA
Tuberomammillary nucleus increases arousal by secreting which of the following
5-HT
Histamines
Orexins
Noradrenaline
GABA
Ventrolateral pre-optic nucleus in the hypothalamus increases sleep by secreting which of the following
5-HT
Histamines
Orexins
Noradrenaline
GABA
Ventrolateral pre-optic nucleus in the hypothalamus increases sleep by secreting which of the following
5-HT
Histamines
Orexins
Noradrenaline
GABA & Galamin
The raphe nucleus secretes which of the following
5-HT
Histamines
Orexins
Noradrenaline
GABA
The raphe nucleus secretes which of the following
5-HT
Histamines
Orexins
Noradrenaline
GABA
The locus coeruleus secretes which of the following
5-HT
Histamines
Orexins
Noradrenaline
GABA
The locus coeruleus secretes which of the following
5-HT
Histamines
Orexins
Noradrenaline
GABA