10-29 Stupor and Coma

Question 1

coma

Answer 1

eyes-closed; unresponsive; cannot respond to stimuli

Question 2

stupor

Answer 2

eyes-closed; can briefly respond to stim

Question 3

sleep

Answer 3

normal; arousable to full responsiveness

Question 4

delerium

Answer 4

nonsleep depression of consciousness where normal reactions to the environment are blunted and replaced by agitated responses.

Question 5

encephalopathy

Answer 5

diffuse suppression of normal cerebral cortical function that often results in stupor or coma.

Question 6

reticular activating system (RAS)

Answer 6

neuronal network involved in wakefulness (alertness & eyes-open readiness to respond)
—central tegmentum of pons and midbrain

Question 7

decorticate posture

Answer 7

pathological response to painful stim
—arms flex, legs extend
—midbrain level

Question 8

decerebrate posture

Answer 8

pathological response to painful stim
—arm and leg extended w/ flexed wrist
—pontine level

Question 9

“locked-in” syndrome

Answer 9

damage to the base of the pons with preservation of consciousness and vertical eye movements, but loss of all other voluntary movements.
SCARY!

Question 10

Cheyne-Stokes resps

Answer 10

pattern of breathing characterized by waxing and waning amplitude of respiration with preserved respriatory frequency.

Question 11

central neurogenic hyperventilation

Answer 11

typically occurs with pontine lesions, with increased depth of respiration.

Question 12

ataxic respiration

Answer 12

pattern of respiration with irregular depth and frequency of respirations with pauses.

Question 13

vestibulo-ocular reflex; def and how to test?

Answer 13

reflex that keeps eyes directed on a target during head movements. It can be elicited by head movments or caloric tests.

Question 14

diencephalic pupils

Answer 14

bilaterally small pupils with lesions of the thalamus

Question 15

anatomical basis of awareness

Answer 15

awareness of self and others is grace à paralell, reverberating back-and-forth circuits between cortex and thalamus

Question 16

Vegetative state?

Answer 16

wakefulness w/o awareness

Question 17

structural causes of coma

Answer 17

herniations, esp:
—uncal transtentorial is 95%
—central transtentorial is rare
—falcine
—foramen magnum

Question 18

metab/toxic causes of coma

Answer 18

—blood flow and temp ∆s
—glucose, O2, electrolytes
—szs, high ICP, meningitis

Question 19

Coma scales

Answer 19

GCS for trauma

FOUR Score for everything else

Question 20

GCS

Answer 20

Eye response 1-4
Motor Response: 1-6
Verbal response: 1-5

Question 21

FOUR Score

Answer 21

Full Outline of UnResponsiveness

1. Eye response
2. Motor response
3. Brainstem reflexes (pupil/cornea)
4. Respiration

Question 22

Bedside exam 5 systems?

Answer 22

1. Level of awareness
   —speak name, shake, “look up/down (locked in), tickle nose, sternal rub
2. RR/pattern (see other card)
3. pupils (sensitive for metab vs. structural)
   —metab coma pupils remain nl ‘til end vs. earlier in structural coma
4. eye mov’ts/VORs
5. Motor response to stims

Question 23

Resp problems and level of brain

Answer 23

post-hypervent apnea (upper dienceph)
cheyne-stokes (lower diencph)
central neurogenic hypervent (midbrain)
apneustic breathing (mibrain/pons)
ataxic DEADLY (pons/medulla)
apnea (medulla)

Question 24

apneustic breathing

Answer 24

abnormal pattern of breathing characterized by deep, gasping inspiration with a pause at full inspiration followed by a brief, insufficient release (wiki)

Question 25

eye findings w/ cortical destruction

Answer 25

deviate TOWARDS lesion

—b/c hemisphere controls contralateral eye?

Question 26

eye findings w/ brain stem destruction

Answer 26

deviates AWAY from the lesion

Question 27

ocular skew suggest lesion where?

Answer 27

pons or midbrain

= when one eye goes up and other goes down

Question 28

ocular bobbing looks like what? originates w/ lesion where?

Answer 28

down quick up fast bob

—pontine lesion

Question 29

Emergency Mgmt

Answer 29

-ABCs
-check glucose + labs + EKG
-give thiamine, naloxone (opioid), flumazenil (benzo), charcoal
—head CT, spine films
—exam/hx
—consider EEG, MRI, LP

Question 30

Two potential causes of coma?

Answer 30

1. diffuse diffuse dysfunction of cerebral hemispheres

2. damage to reticular activating system in brain stem (especially midbrain).

Question 31

What physical findings would indicate that coma was due to diffuse cerebral cortical dysfunction rather that to brain stem damage?

Answer 31

With diffuse cerebral cortical dysfunction you would expect to find normal dysinhibited oculovestibulor reflex eye movement to caloric testing. Motor findings and responses would be the same on both sides of the body (symmetrical). —It is critical to be sure that there is no structural damage to the reticular formation (in brainstem). This is accomplished by determining whether eye movements are affected (extraocular nuclei are close to reticular formation).

Question 32

Common sx of transtentorial herniation

Answer 32

The third cranial nerve is often involved early in transtentorial herniation (with pupillary constrictor fibers usually damaged first). This is usually ipsilateral to the side of expanding lesion. The corticospinal tract is often involved next with contralateral weakness. Occasionally, with large shifts of the brain stem, this may be reversed (false localizing sign: Kernohan’s notch).

Question 33

How do you recognize locked-in syndrome?

Answer 33

In the “locked-in” syndrome, vertical gaze and convergence is usually preserved. Eye opening may be preserved (eye closure is passive only). Other voluntary motions (including horizontal gaze included) are abolished.