Lecture 12: Stupor and Coma

Question 1

Consciousness depends on arousal of the cerebral cortex by the ____________

Answer 1

Brainstem Ascending Reticular Activating System (ARAS)

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

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

Answer 3

Delirium

Question 4

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 4

Stupor

Question 5

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

Answer 5

• Hypothyroid
• Drugs (anticholinergics, TCA’s)

Question 6

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

Answer 6

Long-term antiepileptic use

Question 7

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

Answer 7

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

Question 8

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

Answer 8

• Pupillary responses
• Corneal reflex
• Extaocular movements
• Cough/gag reflex
• Motor responses
• Respiratory pattern

*Start at highest CN and work your way down

Question 9

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

Answer 9

Nuclei/tracts controlling pupils are anatomically adjacent to ARAS

Question 10

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

Answer 10

1) Pontine lesion
2) oPiates
3) Pilocarpine

Question 11

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

Answer 11

Parasympathetic division (usually CN III)

Question 12

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

Answer 12

Bilateral CN III lesion, post-ictal, or intoxications

Question 13

Rule of thumb for lesion location when pupils are constricted?

Answer 13

Sympathetic division (hypothalamus, carotid)

Question 14

Frontal gaze centers deviate eyes where?

Pontine gaze centers deviate eyes where?

Answer 14

• 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 15

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

Answer 15

• Conjugate implies brainstem intact
• Dysconjugate implies brainstem lesion

Question 16

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

Answer 16

Bihemispheric, midbrain

Question 17

Convergence nystagmus or Retractory nystagmus indicates a lesions where?

Answer 17

Mesencephalon

Question 18

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

Answer 18

Pons

Question 19

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

Answer 19

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

Question 20

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

Answer 20

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

Question 21

What are Cheynes-Stokes respirations?

Seen with what disorders?

Answer 21

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

Question 22

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

How do the signs progress?

Motor signs are often?

Answer 22

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

Question 23

What is central transtentorial herniation and the signs/symptoms?

Answer 23

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

Question 24

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

Answer 24

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

*Vertigo

Question 25

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

Answer 25

**Bizarre** respiratory patterns common

Question 26

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

Answer 26

- 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 27

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

Answer 27

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

Question 28

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

Answer 28

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

Question 29

What defines unresponsivness in someone who is truly brain dead? Absence of?

Answer 29

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

Question 30

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

Answer 30

- 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 31

What are the criteria for persistence of brain death?

Answer 31

- **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 32

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

Answer 32

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 33

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

Answer 33

- 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 34

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

Answer 34

- **Asterixis!** - Pt extends arms and wrists, the wrists will twitch!