comas Flashcards
Coma is the absence of ________
consciousness (awareness)
What is consciousness
The state of being awake and aware of one’s surroundings.
The awareness or perception of something by a person.
consciousness requires the hard drive: _____ and the “on” switch ____
hard drive = at least 1 cerebral hemisphere
functional on switch = reticular activating system
The cortex & the mesencephalic reticular activating system are __________ areas
mutually sustaining! you must have one to have the other working
delirium
rapid decline in attention and arousal
stupor
unresponsive and minimal arousal
coma
unresponsive and absent arousal
Plays central role in regulation of the state of consciousness and arousal
reticular activating system RAS
neurons of the reticular activating system are located in
tegmentem of brain stem, lateral hypothalamic area, thalamus, some axons are projected to the cerebral cortex
don’t memorize causes of coma so much as to think
mechanism of action
mechanisms of action of coma
- anatomical lesions
- diffuse processes affecting all systems (toxic, metabolic, infection, hypoxia)
worst score of Glascow coma exam
3
we can access cranial nerve function in coma patients through these findings
pupils, fundi, EOMS, corneal reflex, gag reflex
anisocoria
difference in pupil size
are you awake if you are herniating
no
PEARLA
Pupils Equal And Round, Reactive to Light and Accommodation
Parasympathetic pupil problem characterized by
Greater anisocoria in bright light + larger pupil is not constricting
Parasympathetic pupil problem examples
- Adie’s tonic pupil
- cranial nerve 3 palsy
- pharmacologic dilatiation
Sympathetic pupil problem characterized by
Greater anisocoria in the dark + smaller pupil not dilating
examples of sympathetic pupil problem
horners, Argyll-Robertson pupils
Pharmacologic constriction
Decorticate coma position
arms are to the core
lesion if person is in decorticate posture
Posturing- lesion above the red nucleus
Decerebrate posturing
arms are outstretched and flexed outwards. legs extended.
lesion in decerebrate
below red nucleus
One situation in which it can appear as if someone is in a coma, but they actually have normal attention and arousal is the _____
“the locked in syndrome”
variables that determine brain death
\+ Normal temperature \+ No electrolyte or acid base disturbance \+ No drugs \+ No motor response \+ No brainstem reflexes \+ Apnea \+/- EEG electrocerebral silence \+/- Cerebral Angio; TCD Nuclear scan.
coma can be caused by______ and ___ insults to hemispheres and/or RAS
FOCAL
diffuse
pharmacological treatment of a coma
naloxone, glucose and thiamine
