Consciousness (Lecture 19) Flashcards Preview

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Flashcards in Consciousness (Lecture 19) Deck (40):
1

4 major components of brainstem

cranial nerve nuclei & related structures
long tracts
cerebellar circuitry
reticular formation and related structures

2

long tracts

dorsal column medial lemniscal pathway
lateral corticospinal tract
spinothalamic

3

clinical consequences of damage to CN nuclei and related structures

cranial nerve abnormalities

4

clinical consequences of damage to long tracts

hemiparesis and/or hemianesthesia

5

clinical consequences of damage to cerebellar circuitry

ataxia

6

clinical consequences of damage to reticular formation and related structures

impaired level of consciousness
impairment in autonomic functions (BP, HR)

7

what is the reticular formation

core of cell bodies loosely grouped into nuclei that run throughout the entire length of the brainstem tegmentum (above the basis)

8

function of reticular formation

rostral 1/2: maintenance of alert, consciousl state in the cerebrum
caudal 1/2: autonomic reflexes (HR, BP, respiration, digestion), motor (origin of reticulospinal tract), reflexes involving the head (coughing, sneezing, swallowing, sucking, etc)

9

where is rostral 1/2 of reticular formation found

midbrain and rostral pons

10

where caudal 1/2 of reticular formation found

caudal pons and medulla; continuous with grey matter of spinal cord

11

purpose of reticular activating system

sends info from pontomesencephalic reticular formation to the thalamus and finally the cerebral cortex

12

requirements of consciousness

alertness (RAS)
attention (RAS, limbic system, frontal & parietal lobes)
awareness of surroundings (primary sensory cortices and sensory association cortex)

13

Coma

unarousable unresponsiveness
-pt lies with eyes closed
-brainstem reflexes still present
-no sleep wake cycles

14

brainstem reflexes

blink to threat
pupillary light response
oculocephalic reflex
corneal reflex
gag reflex

15

how to test blink to threat (CN II, VII)

hold eyes open and come toward pt with hand. both eyes should blink

16

how to test pupillary light response (CN II, III)

shine light in eye, pupil constricts

17

how to test oculocephalic reflex (CN VIII, III, VI)

hold eyes open, turn head to left, eyes should move right

18

how to test corneal reflex (CN V, VII)

touch cornea with wisp of cotton, both eyes should blink

19

how to test gag reflex (CN IX, X)

touch back of throat with tongue depressor, pt should gag

20

continuum between consciousness and coma

awake and alert
drowsy
stuporous
comatose
brain death

21

glasgow coma scale

helps determine progonsis in TBI, measures level of consciousness

22

highest possible score on glasgow coma scale

15

23

worst possible score on glasgow coma scale

3

24

what score on the glasgow coma scale indicates a good prognosis

8 or higher

25

bilateral damage to these structures leads to a permanent comatose state

cerebral hemispheres
medial aspect of thalami bilaterally
reticular formation of the pons and midbrain

26

how to perform neurologic exam with someone with decreased level of consciousness

cranial nerve reflexes
observe for motor activity
reflexes
response to pain (sternal rub, nail bed pressure)

27

decorticate posture

LE extended, UE flexed
rubrospinal tract

28

decerebrate posture

UE and LE ext
reticulospinal tract/vestibulospinal tract

29

most common general cause of decreased level of consciousness

bilateral cerebral hemisphere dysfunction (due to trauma or toxic/metabolic causes)

30

what can cause bilateral cerebral hemisphere dysfunction

medications
illicit drugs
liver failure
kidney failure
hypoxia
trauma

31

why do pts with a decreased LOC often require an imaging study of the brain

determine if there is anything that can be fixed

32

Which of the following are present in brain death?
purposeful response to stimuli
sleep-wake cycles
cranial nerve reflexes
cortical electrical activity
cortical blood flow

purposeful response to stimuli- no
sleep-wake cycles- no
cranial nerve reflexes- no
cortical electrical activity- no
cortical blood flow- no

33

Which of the following are present in coma
purposeful response to stimuli
sleep-wake cycles
cranial nerve reflexes
cortical electrical activity
cortical blood flow

purposeful response to stimuli- no
sleep-wake cycles- no
cranial nerve reflexes- yes
cortical electrical activity-abnormal
cortical blood flow-yes

34

Which of the following are present in persistent vegetative state?
purposeful response to stimuli
sleep-wake cycles
cranial nerve reflexes
cortical electrical activity
cortical blood flow

purposeful response to stimuli- no
sleep-wake cycles- yes
cranial nerve reflexes- yes
cortical electrical activity- yes
cortical blood flow- yes

35

Which of the following are present in minimally conscious state
purposeful response to stimuli
sleep-wake cycles
cranial nerve reflexes
cortical electrical activity
cortical blood flow

purposeful response to stimuli- inconsistent
sleep-wake cycles- yes
cranial nerve reflexes- some
cortical electrical activity- yes
cortical blood flow- yes

36

criteria for brain death

no purposeful response to painful stimuli
no CN reflexed
no spontaneous respirations
no reversible cause for coma
EEG or angiogram
2 separate exams required

37

difference between persistent vegetative state and minimally conscious state

they are the same except minimally conscious state my intermittently and inconsistently perform any of the following:
-visual tracking
-follow simple commands
-signal yes/no
-intelligible verbalizations
-restricted purposeful behavior

38

what causes locked-in syndrome

bilateral damage to basis of pons (typically bilateral infarct)

39

symptoms of brain ischemia

-face motor/sensory loss on one side and body motor/sensory loss on the other side
-eye movement abnormalities
-pupillary abnormalities
-nystagmus

40

lateral medullary syndrome caused by

PICA thrombosis