COMA

Question 1

What is a coma?

Answer 1

State of unresponsiveness, in which a patient cannot be aroused

Question 2

Awareness is

Answer 2

Content of consciousness

Question 3

Awareness occurs as a result of …

Answer 3

activity in cerebral cortex (supratentorial, matter) - loss of awareness seen in vegetative state

Question 4

Arousal is

Answer 4

level of consciousness/alertness (high in normal wakefulness)

Question 5

Arousal occurs as a result of

Answer 5

activity with specific brainstem and diencephalic structures (deep in thalamus)

Question 6

In a coma, anesthesia or sleep how is awareness and arousal?

Answer 6

Both are zero

Question 7

In a vegetative state how is arousal…(1)

how is awareness (2)

Answer 7

Arousal is HIGH

Awareness is LOW

Question 8

In a minimally conscious state how is arousal…(1)

how is awareness (2)

Answer 8

1. Arousal is HIGH

2. Awareness is ABOVE zero.. but low

Question 9

In lesions causing coma what happens to cerebral cortex?

Answer 9

BILATERAL damage of both hemispheres or ascending arousal system including

1) paramedian region of upper brainstem or
2) diencephalon on both sides of the brain

Question 10

In locked in syndrome what 3 things in intact

Answer 10

Awareness
Vertical eye movements
Vision

Question 11

Where does lesion in locked in syndrome occur

Answer 11

BELOW level of arousal,

in the caudal pons - wipe out cortico spinal and corticobulbar tract

Question 12

What are some causes of coma ?

Answer 12

1. structural brain disease (supratentorial or infra outside dura, inside dura, blood, pus, tumor)
2. destructive lesions - not extra tissue, loss of oxygen, encephalitis (supra or infra tent)
3. epilepsy, diffuse intrinsic lesions in the brain
4. metabolic disease - severe anoxia, low blood glucose, liver failure, acid-base imbalances

Question 13

What is tonsillar herniation

Answer 13

swelling within cerebellum after infarct, edematous, cerebellum expands, pushes forward
1) first thing that happens is respiratory pause - presses on medullary respiratory center

Question 14

how do you treat a tonsillar herniation?

Answer 14

suboccpital craniotomy

Question 15

how do you treat a patient with an epidural hematoma?

Answer 15

1. ABCs
   REDUCE ICP
2. elevate the head 30 deg
3. hyperventilate - pco2 25-30 (contrict arterioles in brain )
4. mannitol 20% over 30ml (diuertic pull out interstitial fluid)
   evacuate the bleed

Question 16

What happens in right uncal herniation?

Answer 16

1. Decreased arousal - depressed LOC
2. RIGHT CN3 palsy
3. cerebral peduncle involved - LEFT hemiparesis or RIGHT hemiparesis
4. PCAs - cortical blindness -occipital infarct

Question 17

What is the name of the condition in which the left cerebral peduncle is pressed against the left tentorial notch?

Answer 17

Kernohan’s notch - FALSe localizing signals

Question 18

What is the key factor in determining uncal herniation (w/r to side of the lesion?)

Answer 18

it’s the 3rd nerve palsy will be localizing!!!!

hemiparesis cannot be trusted

Question 19

What do asymmetrical occulomotor findings typically identify?

Answer 19

A STRUCTURAL rather than a metabolic cause of a coma (asymmetrical findings and LOC)

Question 20

What does the doll’s eye maneuver tell you?

Answer 20

Localize the lesion to the brainstem

Question 21

1. If you have a RIGHT lateral pontine lesion what will the doll’s eye maneuver show? (RIGHT PPRF nucleus)

Answer 21

1. thrust head to left, eyes dont move gaze paralysis

2. Thrust head to right , eyes move to left

Question 22

If you have a left paramedian pontine lesion (now it’s left PPRF and MLF) what will the doll’s eye maneuver show?

Answer 22

1. Thrust the head to the left, left eye stays put called 1.5 syndrome
2. thrust head to the right, gaze paralysis

(can abduct eye away from side of lesion, cannot adduct eye on side of lesion)

Question 23

If you have a MLF lesion - bilateral internuclear opthamlmoplegia

Answer 23

neither eye can adduct

but both eyes can abduct

Question 24

A lesion in the pons area will result in what kind of pupils?

Answer 24

Pinpoint pupils, no sympathetics

Question 25

A lesion in the midbrain - what happens?

Answer 25

EWN destroyed, fix pupils, not reactive to light

Question 26

Fluctuating level of C could indicate

Answer 26

Metabolic reasons for coma

Question 27

general exam in state of coma

Answer 27

look for general signs look for racoon eyes, look for echymosis behind ears, signs of basal skull fracture liver failure, jaundice, ascites meningeal signs - nuchal rigidity - board coming off bed brudinski's lift head - patient lifts feet look for signs of drug abuse subtle signs of seizures (flickering eye lids)

Question 28

What are the 3 brain stem reflexes to check in a comatose patient?

Answer 28

1. pupillary light reflex 2. doll's eye reflex (occulocephalic) 3. corneal, gag

Question 29

What does extension posture suggest?

Answer 29

lesion at level of upper brainstem - midbrain - exclude neurosurgical interventions - vegetative, no operation

Question 30

what does flexion posturing suggest?

Answer 30

lesion at diencephalon