Alterations in consciousness and Coma Flashcards
Define Consciousness
Altert + Content
Define Alert
Eyes are open
Define Content
awareness in a cognitive sense
define Coma
impairment or absence of awareness
define Dementia
Issue of Content not awareness
define delirium
Mostly issue of content but also an issue of awareness
Define obtundation
external stimuli is needed to wake someone up but they only stay awake briefly
Define stupor
external stimulus is consistently required to keep someone awake
Is sleep a consciences state
NO- b/c there is no arousal BUT body maintains the ability to return to a consciences state.
body responds to external stimuli
Anatomy and function of the reticular activating formation in the brainstem- what provides the input and output for the brainstem
Brainstem: pons and mesencephalon
Input: spinal cords gets info from the periphery, cortex provides higher level input, and the cerebellum provides coordination
Output is to the spinal cord
anatomy and physiology of the reticular activating formation in the supratentorial areas
Cortex and diencephalon (thalamus) describe the content and awareness at a higher level
What brain structures need to be working for conscience
One hemisphere
Brainstem
Connection between the two
What are the two types of posture
Decorticate and Decerebrate
what is decorticate posture?
where is the lesion
The lesion is superior to the red nucleus
UE flexion, LE extension
= mummy baby
What is Decererate posturing
where is the lesion
Lesion is inferior to the red nucleus in the mid collicular region
extensor posturing of UES and LES
Which posture has a worse prognosis- Decorticate or Decerebrate?
Decerebrate
What condition often causes Decerebrate posturing
Pontine Strokes
What can cause stupor or coma?
anything that messes with the requirements of consciencenes:
hypoxia
Hypo or hyperglycemia
organ dysfunction of liver, kidney, or adrenal
toxin or poison
metabolic dz ie thymus
infection
structural dz- tumor, infarct, herniation
trauma
What is the Glasgow Coma scale
What are the max and min scores
what do they mean
What is the cutoff for serious brain injury
way to score severity of a coma
min score is 3 which is very bad
max score is 15
cutoff for serious brain injury is 8
what tests are used to judge the coma or locate a lesion
galsgow coma scale
spontaneous eye reflex
oculovestibular or caloric testing
oculocephalic dolls eye test
What part of the brain is responsible for the spontaneous eye reflex
What is normal
what happens when there is a lesion
what happens when there is a seizure
Frontal gaze centers in the cortex
normally causes eyes to move spontaneous in the oposite direction they were moving
when there is a lesion they will move in the same direction
when there is a seizure, so there is hyperactivity, the eyes will deviate to the opposite side
What is caloric testing
what reflex is it measuring
Caloric testing is when cold or hot air or water is placed into a comatose patients ear and watch the nystagmus of the eye
Tests Oculocephalic reflex
COWS
Cold water- nystagmus Opposite side
Warm water- nystagmus Same side
If there is no nystagmus the reflex is not intact, if there is no movement at all it means its really bad
what does the doll’s eye test- test
what is normal
what is pathological
what does it mean
test the oculocephalic reflex
Normally pt should be able to keep their eyes fixed if you turn the head quickly
It is pathological if the eyes simply turn with the head
indicates a low brain stem lesion
Definition of brain death
cessation of brain function
what are the components of brain death
No response to deep pain
No CN responses- corneal (5,7), gag (9,10)
No oculocephalic or oculovestibular reflexes
Apnea
Vitals are ok- temp >90, SBP>90
Spinal reflexes may be intact
