8.1.3 Disorders of Consciousness

Question 1

Fast eye movements indicate that what is intact? Where is lesion in these coma patients?

Answer 1

Cortex working; psychogenic

Question 2

Define coma, stupor, and lethargy

Answer 2

Different LOCs that are distinguished between based on the stimulus required to induce eye opening in the patient

Lethary -> Speech

Stupor -> Touch, Pain

Coma -> No stimulus will induce eye opening

Question 3

What are some ways to distinguish b/t metabolic and diencephalic

Answer 3

Obvious toxic metabolic cause (metabolic)

If none, obtain stat CT angiogram (look for occlusion at top of basilar artery

Question 4

What are some tests to determine etiology of toxic-metabolic encephalopathy?

Answer 4

Labs

Stat lumbar puncture

EEG (if hx of seizures)

MRI

Question 5

Possible lesional categories?

Answer 5

Late supratentorial or subtentorial

Question 6

What are the components of the neurological exam essential for determining cause of coma?

Answer 6

LOC

Pupilary response

Extraocular Movements

Muscle response (not as useful b/c of variability)

Question 7

Possible lesional categories? Let’s narrow it down – nothing is found on CT.

Answer 7

Metabolic, diencephalic, or early supratentorial

Question 8

Slow eye movements indicate that what system is intact? What are some tests to assess these eye movements?

Answer 8

Brainstem

Question 9

Possible lesional categories? What would be the next step?

Answer 9

Metabolic, diencephalic, or early supratentorial; CT to rule out supratentorial mass

Question 10

What are the major lesional categories of coma?

Answer 10

Psychogenic

Metabolic

Diencephalic

Supratentorial

Subtentorial

Question 11

What is the pupilary condition and level of response in the different lesional categories responsible for coma?

Answer 11

Psychogenic: fast eye movements present

Brainstem intact (metabolic, diencephalic, early supratentorial) - small and reactive

Brainstem lesion (late supratentorial, subtentorial) - mid-range and unreactive

Question 12

What is the status of eye movements in the different lesional categories of coma?

Answer 12

Question 13

What is an algorithmic approach to evaluate a patient with decreased LOC?

Answer 13

1. Type of LOC - stimulus for eye opening
2. Pupillary
3. Eye Movements
4. CT Scan, if necessary
5. Labs, lumbar puncture, EEG (with hx of seizures), MRI to determine etiology