Coma and Brain Death

Question 1

unarousable unresponseive state

Answer 1

coma

Question 2

brain stem reflexes present, no cortical function

Answer 2

coma

Question 3

impaired consciousness, limited responsiveness

Answer 3

obtunded/stuporous

Question 4

persistent severe cortical impairment

Answer 4

vegetative state

Question 5

has sleep wake cycles, possible pain responsiveness, eyes periodically move/open

Answer 5

vegetative state

Question 6

solitary unilateral cerebral lesion gives coma if

Answer 6

it adversely affects opposite hemisphere via edema/herniation

Question 7

important for wakefulness/arousal? brain stem lesion here can give?

Answer 7

reticular formation

coma

Question 8

asymmetric neuro signs suggest…

Answer 8

structural lesion (ex: tumor, ischemic infarct, hemorrhage)

Question 9

symmetric neuro signs suggest

Answer 9

diffuse/toxi-metabolic process (ex: anoxia)

Question 10

coma doesn’t have motor responses but can show which two automated movements

Answer 10

decorticate posturing and decerebrate posturing

Question 11

upper limbs flex
lower limbs extend
lesion at cerebral cortex/hemisphere

Answer 11

decorticate posturing

Question 12

upper and lower limbs extend

lesion at midbrain (red nucleus)

Answer 12

decerebrate posturing

Question 13

alternating tachypnea and apnea

Answer 13

crescendo-decrescendo breathing of Cheyne-stokes

Question 14

cheyne stokes breathing results from ___ involvement due to metabolic encephalopathy

Answer 14

bilateral cortical involvement

Question 15

inc RR/hyperventilation due to anxiety or pulm congestion is called? lesion where?

Answer 15

central neurogenic hyperventilation - lesion in low midbrain to upper pons

Question 16

variable breaths at irregular rate

Answer 16

ataxic respiration - medulla lesion - emergency requiring intubation/ventilation

Question 17

reflex preserved in coma

Answer 17

pupil light reflex

Question 18

large fixed pupil

Answer 18

midbrain lesion involving CN3 fibers (parasympathetics)

Question 19

large blown fixed pupil

Answer 19

compression of CN3 from uncal herniation

Question 20

small pinpoint pupils

Answer 20

pontine lesion, narcotics, or cholinergic eyedrops

can be nl in elderly pts

Question 21

eyes stay fixed regardless of head movement

Answer 21

doll’s eyes - oculocephalic reflex

Question 22

cold water in ear - eye moves slowly toward cold ear

Answer 22

cold caloric oculovestibular reflex

Question 23

cold water caloric - nystagmus seen when

Answer 23

nystagmus in opp direction (away from cold water) for conscious patient

Question 24

2 key things to check for in coma pt

Answer 24

hypoxia and hypoglycemia

Question 25

dec icp in coma pts via

Answer 25

mechanical hyperventilation and osmotic diuretics (mannitol) or dexamethasone to dec edema

Question 26

irreversible loss of function for brainstem and cerebrum

Answer 26

brain death

Question 27

no neuro improvement despite adequate treatment of any reversible causes of coma

Answer 27

brain death

Question 28

reversible causes of coma

Answer 28

drug intoxication, circulatory shock, hypothermia

Question 29

observation period for coma in:
adult
7 day - 2 mo old
2 mo - 1 y/o
1 y/o+

Answer 29

adult: 6 hrs
7 day - 2 mo old: 48 hrs
2 mo - 1 y/o: 24 hrs
1 y/o+: 12-24 hrs

Question 30

only things that may persist with brain death

Answer 30

muscle reflexes, babinski

Question 31

confirmatory test of brain death - respiratory

Answer 31

apnea test - no breathing even if pCO2 60+

Question 32

confirmatory test of brain death - brain activity

Answer 32

flat line or isoelectric EEG

Question 33

confirmatory test of brain death - vessels

Answer 33

cerebral angiography - failure of intracranial blood flow over 10 min

Question 34

preferred confirmatory test of brain death

Answer 34

radioisotope brain scan (can be done bedside)

Question 35

decorticate vs decerebrate posturing - lesion locations

Answer 35

decorticate - lesion at cerebral cortex/hemisphere

decerebrate - lesion at midbrain (red nucleus)

Question 36

4 confirmatory tests of brain death

Answer 36

apnea test
flat line
cerebral angiography
radioisotope brain scan