A7. Classification of unconscious conditions Flashcards
Clear consciousness definition
The brain’s ability to react (arousal or
alertness) and the adequate use of contents of memory and to
think (awareness).
Allows the adaptation of the individual to the environment and is the basis of cognition.
Awareness depends on alertness.
The anatomical basis of arousal is the
intact functioning of the
ascending reticular activating system (ARAS)
ascending reticular activating system (ARAS)
is
composed of the
- pontomesencephalic reticular formation,
- monoaminergic networks of the diencephalon and
- the intralaminar and medial nuclei of the thalamus
Disorders of consciousness:
- Disorder of arousal
- Disorder of awareness
NOTE: Locked in syndrome - Not disorder of consciousness, but often misdiagnosed as this.
Is locked in syndrome a disorder of consciousness?
Not disorder of consciousness, but often misdiagnosed as this.
what are the characteristics of Disorders of arousal
- Reduced arousal
- sleep-like state
- won’t react to awakening stimuli.
list Disorder of arousal
● Somnolence - Mildest form. Awakens with verbal stimuli, but is asleep without stimuli.
● Stupor - Patient may open eyes to painful stimuli, verbal is not enough. Slow and inappropriate reaction to stimuli.
● Coma - Cannot be awakened. Abnormal posture (decorticate or decerebrate).
i. Coma I - Preserved brainstem reflexes
ii. Coma II - Lost brainstem reflexes
● Somnolence
Mildest form of Disorder of arousal.
Awakens with verbal stimuli, but is asleep without stimuli.
Disorders of consciousness:
A. Disorder of arousal
Stupor
- Patient may open eyes to painful stimuli, verbal is not enough.
- Slow and inappropriate reaction to stimuli.
Disorders of consciousness:
A. Disorder of arousal
Coma
- Cannot be awakened.
- Abnormal posture (decorticate or decerebrate).
i. Coma I - Preserved brainstem reflexes
ii. Coma II - Lost brainstem reflexes
Disorders of consciousness:
A. Disorder of arousal
coma 1 VS coma 2
i. Coma I - Preserved brainstem reflexes
ii. Coma II - Lost brainstem reflexes
Disorders of consciousness:
A. Disorder of arousal
characteristics of Disorder of awareness
- Inadequate thinking and behavior.
- Global CNS function is impaired.
- Arousal is normal, but content of memory is disturbed, inaccessible or used inappropriately
- Signs of focal cognitive deficit (e.g. alexia, acalculia) are NOT part of this.
Signs of focal cognitive deficit (e.g. alexia, acalculia) - are they a part of disorder of awareness
- Signs of focal cognitive deficit (e.g. alexia, acalculia) are NOT part of this.
Arousal is normal, but content of memory is disturbed, inaccessible or used inappropriately
disorder of awareness
list Disorder of awareness
- Persistent vegetative state (decorticate state, apallic syndrome)
- Akinetic mutism
- Confusion
- Delirium