DSA 38 Stupor and Coma

Question 1

patient presents with unilaterally fixed and dilated pupils. where is the lesion?

Answer 1

CN III damage due uncal herniation

Question 2

patient presents with bilaterally unresponsive pinpoint pupils. where is the lesion?

Answer 2

pons lesion

Question 3

what would bilaterally unresponsive mid-sized pupils indicate?

Answer 3

midbrain lesion; midposition and fixed

Question 4

patient presents with small pupils and reactive. where is the lesion?

Answer 4

diencephalic

Question 5

patient presents with large, fixed pupils as well as hippus (spamodic or rhytmic contraction of pupil) present. where is the lesion?

Answer 5

tectal

Question 6

what is the mechanism of coma due to drug intoxication?

Answer 6

no damage to the RAS; drug toxicity depresses the cerebral cortex diffusely and the effect will last until the drug is metabolized

Question 7

the _______ (cerebral cortex/brainstem) more vulnerable to anoxic, ischemic, and metabolic insults.

Answer 7

cerebral cortex

Question 8

physical exam presentation: been ill for some time; gradual decline of mental and psychomotor function usually precedes coma. what is the cause of the coma?

Answer 8

coma due to systemic metabolic disease

Question 9

list some major etiological causes of coma due to decreased cerebral perfusion or hypoxemia.

Answer 9

myocardial infarction, cardiac arrhythmia

Question 10

what are the absolute minimum requirements for consciousness?

Answer 10

1. ) intact RAS
2. ) partially functioning cerebral cortex of at least one hemisphere
3. ) adequate metabolic milieu

Question 11

fill in the blank: patient may be declared brain dead if comatose and lacking any signs of active brainstem reflexes including ________.

Answer 11

positive apnea test, no activity on EEG, no intracranial blood flow

Question 12

you perform ice water calorics on comatose patient with intact MLF (intact brainstem). what do you expect to see?

Answer 12

eyes would deviate toward side of ice water irrigation and the nystagmus response is lost.

Question 13

you perform ice water calorics on patient. ipsilateral eye ABducts but contralateral eye does not ADduct. what does this indicate?

Answer 13

INO–lesion between abducens nucleus in pons and oculomotor nucleus in midbrain

Question 14

where is the lesion in locked in syndrome?

Answer 14

lesion at the caudal pons/proximal medulla

Question 15

true or false: the RAS and cerebral cortex are dysfunctional in locked in syndrome.

Answer 15

false, they are intact

Question 16

describe the clinical presentation of locked in syndrome.

Answer 16

patient is awake, aware, has wake/sleep cycles, but has complete paralysis except for eye movements and blinking.

Question 17

in what condition does delirium most often present?

Answer 17

metabolic encephalopathies, but also in structural brain lesions and infections

Question 18

list three mechanisms which can result in coma.

Answer 18

1. ) supratentorial mass lesion affecting RAS
2. ) subtentorial lesion afecting RAS
3. ) diffuse or multifocal dysfunction

Question 19

what is the most likely vascular cause of coma?

Answer 19

ischemic infarction of the brainstem–implicates the vertebrobasilar arterial system

Question 20

there is _____ (rarely/almost always) focal neurologic deficit in patient with metabolic coma.

Answer 20

rarely

Question 21

there is _____ (rarely/almost always) focal neurological deficit in patient with structural brain induced coma.

Answer 21

almost always

Question 22

how does vegetative state differ from coma?

Answer 22

coma lacks both awareness and wakefulness. patients in a vegetative state may have awoken from a coma, but still have not regained awareness–can open their eyelids occasionally and demonstrate sleep-wake cycles, but completely lack cognitive function

Question 23

patient in coma has pupils equally reactive to light. suggests which type of coma?

Answer 23

toxic-metabolic coma

Question 24

what is the first step in evaluating an unconscious patient?

Answer 24

see if the patient responds to your voice

Question 25

presence of DTRs in unresponsive patient indicates?

Answer 25

nothing about the cause of the coma