(37) Coma

Question 1

lethargy vs hyperinsomnia

Answer 1

lethargy = sleepy but easily aroused
hypersomnia = excessively sleepy but normal cognition when awakened

Question 2

obduntation vs stupor

Answer 2

obduntation = mental blunting with decreased alertness

stupor = eye open only after vigorous stimulation and then go back to deep sleep

Question 3

coma vs stupor

Answer 3

stupor = eye open only after vigorous stimulation and then go back to deep sleep

coma = eyes remain closed even after vigorus stimulation

Question 4

defn of delerium

Answer 4

disorientated, hallucinations, misperception of sensory stimuli; fluctuate between quiet/sleepy and alert/agitated

Question 5

What is “abulia”? Damage to what area causes it?

Answer 5

awake but apathetic and no sponteneity

bilateral frontal lobe disease, lobotamized

Question 6

What is “akinetic mutism”? Damage to what area causes it?

Answer 6

silent, altert looking but no mental activity with vigorous stimulation

frontal lobes and hypothalamus

Question 7

Difference between minimally conscious states and vegetative state?

Answer 7

MCS = fragements of awareness

vegetative = awake, no awareness or meaningful interaction with the environment

Question 8

can reach for objects, grunt or gesture in response to a command, visually fixate and track but are unable to do much more

Answer 8

minimally conscious state

Question 9

What are the 2 components of consiousness

Answer 9

arousal = ascending tracts
content = cortical circuits (awareness and cognition)

Question 10

lesions in what areas are known to cause coma

Answer 10

extensive bi-hemispheric disease
diencephalon (thalamus and hypothalamus)
peri-aqueductal gray
upper 1/3 of ponitine tegmentum

Question 11

areas that produce coma when damaged are called

Answer 11

ascending arousal system

Question 12

Describe the parts of the ascending arousal system and what they do

Answer 12

2 cholinergic nuclei that inhibit thalamic neurons that synchronizes with cortex to induce sleep

monoaminergic nuclei that improve signal to noise ration and avoid misperception of incoming stimuli

Question 13

sleep promoting center of the brain. how does it work?

Answer 13

VLPO–sends GABA and galanin (inhib neuropeptide) to the many nuclear centers that promote wakefulness

Question 14

ascending arousal system receives feedback from what sources

Answer 14

thalamus, limbic system, fronto-parietal assc cortex

…these areas mediate emotional memories and permit concentrated attention to one sensory modality when necessary…

Question 15

loss of feedback to ascending arousal system leads to…

Answer 15

abulia or akinetic mutism = apathy and indifference to sensory stimuli
…i.e. cannot be aroused?….

Question 16

What parts of the brain herniate in a transtentorial heriation

Answer 16

temporal lobe or uncus (of temporal lobe)

Question 17

complications of uncal herniation

Answer 17

1. compression of occulomotor nerve (mydriasis + eye down and out)
2. compress midbrain –> Duret’s hemorrages
3. PCA compression –> ipsilateral stroke in occipital lobe

Question 18

what is a bilateral uncal herniation called?

Answer 18

central herniation

Question 19

herniation that pushes brain under the falx cerebri

Answer 19

falcrine herniation (herniation of cingulate gyrus)

Question 20

complication of falcrine herniation

Answer 20

ACA compression (/stroke)

Question 21

cause of lethargy in central herniations

Answer 21

compression of reticular grey in thalami

Question 22

cause of small reactive pupils in central herniation

Answer 22

compression of hypothalamus

Question 23

if central herniation is not corrected, the pupils will go from being small to… why?

Answer 23

fixed in mid position bc para will get knocked out too when the herniation compresses the midbrain (Endinger-Westphal nucleus)

Question 24

Late signs of central herniations

Answer 24

flexor then extensor posturing then cheyne-stokes respirations

Question 25

what is the distinct syndrome caused by pontine hemorrhages

Answer 25

abrupt coma + pin point pupils + flaccid paralysis or flexor rigidity + horizontal gaze paralysis (eyes can only move vertically) + ocular bobbing (up and down)

Question 26

What are patients that have pontine hemorrhages at risk for

Answer 26

locked in syndrome

Question 27

in metabolic encephalopathy pupils are (reactive or inactive to light)

Answer 27

reactive | **in structural causes of coma they are inactive

Question 28

3 most common causes of encephalopathy in the elderly

Answer 28

dehydration, infection, drug intoxication

Question 29

presentation of metabolic encephalopathy

Answer 29

non-focal neuro exam defectis negative CT reactive pupils myoclonis, asterixes, and tremor

Question 30

what drugs are empriacally given to pateints in a coma

Answer 30

D50 THEN thamine, naloxone **D50 BEFORE thiamine to prevent Wernicke's enchephalopathy

Question 31

normal vital signs suggest what kind of coma

Answer 31

psychogenic

Question 32

cheyne stokes respirations can be an early sign of

Answer 32

central and uncal herniations

Question 33

decerebrate posturing =

Answer 33

extensor

Question 34

flexor center is in ____ and extensor center is in _____

Answer 34

``` flexor = midbrian extensor = pons ```

Question 35

extensor posturing predominates when ___ is lost/damaged

Answer 35

midbrian / flexor center

Question 36

decorticate posturing =

Answer 36

flexor

Question 37

flexor or extensor posturing worse

Answer 37

extensor

Question 38

poor prognosis if on day __ of coma, the ___ reflex is absent and absence of purposeful _____

Answer 38

day 3 | no corneal reflex and no purposeful movements

Question 39

aneurysm in ___ artery may also compress CN III

Answer 39

posterior communicating