diff dx neuro - coma lecture

Question 1

disruption to what mechanism leads to coma?
more about this system
damage needs to be…

Answer 1

feedback mechanism btwn reticular activating system (RAS) & cerebral cortex maintains consciousness.

RAS is activated by various sensory inputs

damage needs to be bilateral to RAS or brainstem for it to cause a coma

Question 2

some things that define a coma (5)

Answer 2

1. state of profound unresponsiveness
2. inability to obey commands
3. inability to verbally respond to commands
4. inability to open eyes and visually tack
5. lack of sleep-wake cycles

Question 3

levels of coma/ TBI (3)

Answer 3

1. minimally conscious state (light coma)
2. deep coma
3. vegetative state

Question 4

minimally conscious state (light coma) descriptors

Answer 4

1. may have reflexes (primitive or disorganized response to stimuli)
2. minimal but purposeful awareness
3. gestural or verbal responses (mumbling)
4. movements or behaviors that are not reflexive*

Question 5

deep coma hallmark

Answer 5

no response to any stimuli, even painful

Question 6

vegetative state (3)

Answer 6

1. state of arousal w/o behavioral evidence of awareness or ability to interact with external environment
2. rudimentary arousal and apparent sleep-wake cycles
3. may have spontaneous eye opening but no tracking or purposeful movements

Question 7

locked in syndrome

Answer 7

pt apears to be in a coma, but all higher cortical functions intact -CNS function intact but pt cannot speak, move or breath

Question 8

glasgow coma scale
3 things its scored on
top & bottom ranges

Answer 8

scored on:

1. eye opening
2. motor response
3. verbal response

score of 3-5 is worst, 62% change of death
12-14 is the best

3= worst possible score
15 = best possible score

Question 9

pupillary response to light

Answer 9

testing parasympathetic fibers to CN III. intact responses are a positive sign for reversible coma

Question 10

initial neurological exam
oculocephalic movements
def & what controls this

Answer 10

oculocephalic movement = dolls head, eyes should move in opposite direction to rapid passive movement, person in comas eyes stay fixed.
pons & midbrain must be intact for this to occur

Question 11

initial neurological exam

oculovestibular test and 3 possibe responses

Answer 11

oculovestibular response = COWS
putting cold water in someones eyes causes eyes to go towards that side, then rapid nystagmus to midline = awake or light coma

unconscious pt (pons & midbrain intact) = no return nystagmus

pons, midbrain lesion = no response to testing

Question 12

pathological posturing positions & what it means
decorticate
decerebate
flaccid

what causes these types of posturing?

Answer 12

decorticate = lesion of cortico-spinal tracts at the thalamus & internal capsule
flexion of UE, extension of LE

decerebate = pons & vestibular nucleus intact, midbrain or cerebellum lesion
tone influenced by TNR
extension of all 4Es

flaccid = lower brainstem lesion

loss of inhibitory control from CNS

Question 13

5 motor responses (in order)

Answer 13

1. purposeful
2. withdrawl from noxious stimuli
3. decorticate
4. decerebrate
5. partial decerebrate
6. flaccid

Question 14

TBI

Answer 14

any pt with blunt injury to head, if they are in a coma of lose consciousness for even a second, they are considered TBI

Question 15

space occupying lesions
epidural hematoma
subdural hematoma
subarrachnoid hemorrhage

Answer 15

these are all lesions outside the brain but can cause deformations to brain because of pressure

epidural hematoma = bleeding btwn inner skull & duramater
from arterial bleeding, fast onset of symptoms

subdural hematoma = bleeding btwn dura and arachnoid
can progress in days to weeks

subarachnoid hemorrhage = bleeding btwn arachnoid & pia mater
most common site, from trauma, aneurism, MVA

Question 16

concussion
location
grade 1 , & 3

Answer 16

a concussion is any loss of consciousness, due to lesion inside cerebral cortex

grade 1 is transient confusion with no LOC, symptoms resolve w/i 15m

grade 2 is transient confusion with no LOC, but symptoms last longer than 15 min

grade 3 LOC for seconds -> minutes, needs immediate hospitalizatition

Question 17

second impact syndrome

Answer 17

sustaining a second injury soon after the first. if brain is still healing, this can result in hematoma formation, coma or death

Question 18

post-concussion syndrome

Answer 18

dizziness, impaired memory & concentration, sensitivity to light, headache & irritability

may take weeks or months to completely resolve

Question 19

rancho los amigo cognitive scale
what it does
best and worst levels

Answer 19

tests level of cognitive functioning & is used to document status of patient & plan interventions

1 = no response to any stimuli
5 = confused, inappropriate, non-agitated
10 = purposeful, appropriate, but still modified independence (needs psych support)