Persistent Vegetative States Flashcards
Define consciousness.
State of full awareness of the self and one’s
relationship to the environment.
What are the five disorders of consciousness described in this lecture?
Normal consciousness Coma, sleep, or anaesthesia Vegetative state Minimally conscious state Locked in syndrome
How does arousal and awareness differ between a normal consciousness state and a vegetative state?
Both have full arousal but in vegetative state, there is no awareness
How does arousal and awareness differ between a vegetative state and a minimally conscious state?
In minimally conscious state, there is slightly more awareness
How does arousal and awareness differ between a coma and locked in syndrome?
In locked in syndrome, there is full arousal and awareness. In a coma, there is no arousal or awareness.
What is a vegetative state?
Complex neurological condition in which patient appears to be awake but shows no sign of awareness of themselves or their environment.
What is a minimally conscious state?
Wakefulness accompanied by inconsistent but reproducible signs of awareness.
◦Non reflexic response to sensory stimulus.
◦Awareness of self or environment.
◦Language comprehension or expression
◦Visual tracking
◦Lack of object use
◦ Akinetic Mutism
How does akinetic mutism present?
Awake but diminished drive to respond
When is a vegetative state considered persistent?
If the patient has been in the state for more than a month
When is a vegetative state considered permanent?
If the patient has been in the state for more than 12 months for traumatic injury or 6 Months for anoxic injury
What happens to the brain in a vegetative state?
Widespread subcortical white matter cell death
There is a disconnection from fronto-parietal cortex to the thalamus.
There is loss of inhibition from the striatum to the globus pallidus interna.
There is excess inhibition from the globus pallidus interna to the thalamus and to the pedunculopontine nuclei.
How is vegetative state diagnosed? (4)
• Clinical history • Repeated observation of spontaneous and elicited behaviour. • Imaging • Electrophysiology
What are the diagnostic criteria for vegetative state? (3)
Cycles of eye opening and closing giving the appearance of sleep wake cycle.
Complete lack of self or environment.
Complete or partial preservation of hypothalamic and brain stem autonomic functions.
How often is vegetative state misdiagnosed (%)?
37% - 45%
When can artificial nutrition and hydration be stopped?
By 12 months, but it requires the approval of the High Court. The patient is represented legally by the official solicitor and the court has to decide whether continued
treatment will be in the patient’s best interests.
