Clin: Stupor and Coma

Question 1

What is central transtentorial herniation and the signs/symptoms?

Answer 1

• Herniation into foramen magnum
• Leads to early coma, small pupils, normal EOM’s, posturing and later bilateral fixed pupils
• Respiratory arrest and death

Question 2

Impaired consciousness means involvement of what 3 things?

Answer 2

1. Diffuse or bilateral impairment of both cerebral hemispheres, or
2. Failure of brainstem ARAS, or
3. BOTH

Question 3

What is the characteristic signs of someone with diffuse/metabolic injury of the nervous system (i.e., motor signs, consciousness, breathing, and presentation)?

Answer 3

• Confusion and stupor commonly precede motor signs
• Motor signs usually symmetrical
• Pupillary rxns usually preserved
• Asterixis, myoclonus, tremor, seizures common
• Acid-base imbalance with hyper or hypoventilation
• Fluctuating level of consciousness

Question 4

Rule of thumb for lesion location when pupils are enlarged bilaterally?

Answer 4

Bilateral CN III lesion, post-ictal, or intoxications

Question 5

Which state of altered consciousness is represented by arousal only to noxious stimuli and not enviornmental, only rudimentary awareness (i.e., purposeful motor response)?

Answer 5

Stupor

Question 6

The initial signs of a supratentorial mass lesion are usually (global or focal)?

How do the signs progress?

Motor signs are often?

Answer 6

• Initial signs usually focal
• Progression of signs is rostral to caudal (i.e., herniation pushing down)
• Motor signs are often asymmetric

Question 7

What are the criteria for persistence of brain death?

Answer 7

• 6 hours w/ confirmatory (flat) EEG: performed to tech. standards of AEES
• 12 hours w/o a confirmatory isoelectric EEG
• 24 hours for anoxic brain injury w/o confirmatory isoelectric EEG

Question 8

What must be known when making the call of brain death?

Answer 8

Cause of the coma should be known, it MUST be adequate to explain the clinical picture, and it MUST be irreversible

Question 9

Which level of the pons is assessed with the Oculocephalic manuever (Doll’s Eyes) vs. Caloric (oculovestibular) reflex test?

Answer 9

• Oculocephalic = mid pons; assess CN III, IV, and VI
• Caloric = lower pons

Question 10

What is the location of the lesion if the eyes have a ping-pong nystagmus?

Answer 10

Bihemispheric, midbrain

Question 11

Which test can be done to clinically document someone as being brain dead?

Answer 11

• Apnea test
• Disconnect ventilator –> Catheter w/ 100% O2 and observe chest wall and abdomen for movement
• No respiratory movements for 8 mins (PCO₂ >60mmHg

Question 12

What are specific interventions that can be done to reduce ICP?

Answer 12

• Elevate head of bed
• Intubate and hyperventilate to PCO2 of 20 mmHg
• Use mannitol for ischemic lesions
• Use decardron for tumor, abscess, and perhaps cerebral hemorrhage

Question 13

What defines unresponsivness in someone who is truly brain dead?

Absence of?

Answer 13

• Unresponsive to ALL sensory input, including pain and speech
• Absent brainstem reflexes

Question 14

What is Decorticate vs. Decerebrate posturing and where is the lesion for each?

Answer 14

• Decorticate = arms flexed, legs extended (hemispheric)
• DEcrebrate = all extremities Extended (brainstem)

Question 15

During a general medical exam of the skin of a patient with impaired consciousness what should be considered with dry skin?

Answer 15

• Hypothyroid
• Drugs (anticholinergics, TCA’s)

Question 16

Rule of thumb for lesion location when pupils are enlarged on one side?

Answer 16

Parasympathetic division (usually CN III)

Question 17

Frontal gaze centers deviate eyes where?

Pontine gaze centers deviate eyes where?

Answer 17

• Frontal gaze centers deviate eyes to opposite side (i.e., if right area is dysfunctional, there is no drive to the left, so eyes will be looking right)
• Pontine gaze centers deviate eyes to same side

Question 18

Consciousness depends on arousal of the cerebral cortex by the ____________

Answer 18

Brainstem Ascending Reticular Activating System (ARAS)

Question 19

During a general medical exam of the skin of a patient with impaired consciousness what should be considered with acne?

Answer 19

Long-term antiepileptic use

Question 20

What are the 3 intial steps of managing a comatose patient?

Answer 20

1) A: insure patent airways
2) B: insure breathing and adequate oxygenation
3) C: insure adequate circulation and control any active bleeding

*Stabilize neck, get C-spine films if trauma suspected

Question 21

What is commonly seen preceding brainstem dysfunction (4 D’s) due to a subtentorial mass lesion?

Answer 21

1. Dysequilibrium
2. Dysarthria
3. Dysphagia
4. Diplopia

*Vertigo

Question 22

What does conjugate vs. dysconjugate gaze imply about the brainstem?

Answer 22

• Conjugate implies brainstem intact
• Dysconjugate implies brainstem lesion

Question 23

Large, pressure producing supratentorial mass lesions can cause coma how?

Answer 23

• Dysfunction in the upper ARAS
• Downward herniation of the brain to compress the ARAS

Question 24

What is the characteristic sign of Hepatic dysfunction causing stupor and coma?

Answer 24

• Asterixis!
• Pt extends arms and wrists, the wrists will twitch!

Question 25

What must be ruled out before making the call that someone is brain dead?

Answer 25

- Sedative intoxication - Hypothermia (\<90F) - Neuromuscular blockage - Shock \*All can mimic brain death\*

Question 26

Which state of altered consciousness is represented by disorientation, stimuli misinterpretation, and hallucinations (visual)?

Answer 26

Delirium

Question 27

Convergence nystagmus or Retractory nystagmus indicates a lesions where?

Answer 27

Mesencephalon

Question 28

Bobbing nystagmus (rapid down, slow up) indicates a lesion where?

Answer 28

Pons

Question 29

What are Cheynes-Stokes respirations? Seen with what disorders?

Answer 29

- Hyperpnia regularly alternating w/ apnea (bilateral hemispheres or diencephalon) - Many disorders ranging from **metabolic** to **structural**

Question 30

What are the 3 P's associated with pinpoint pupils?

Answer 30

1) **P**ontine lesion 2) o**P**iates 3) **P**ilocarpine

Question 31

Rule of thumb for lesion location when pupils are constricted?

Answer 31

**Sympathetic** division (hypothalamus, carotid)

Question 32

What are the respiratory patterns of someone with a subtentorial mass lesion?

Answer 32

**Bizarre** respiratory patterns common

Question 33

Why do absent or unequal pupillary responses imply a brainstem lesion?

Answer 33

Nuclei/tracts controlling pupils are **anatomically** adjacent to **ARAS**

Question 34

What are the **essential** elements of the neurological examination for a patient with stupor?

Answer 34

- Pupillary responses - Corneal reflex - Extaocular movements - Cough/gag reflex - Motor responses - Respiratory pattern \*Start at highest CN and work your way down