DSA 38 Stupor and Coma Flashcards
patient presents with unilaterally fixed and dilated pupils. where is the lesion?
CN III damage due uncal herniation
patient presents with bilaterally unresponsive pinpoint pupils. where is the lesion?
pons lesion
what would bilaterally unresponsive mid-sized pupils indicate?
midbrain lesion; midposition and fixed
patient presents with small pupils and reactive. where is the lesion?
diencephalic
patient presents with large, fixed pupils as well as hippus (spamodic or rhytmic contraction of pupil) present. where is the lesion?
tectal
what is the mechanism of coma due to drug intoxication?
no damage to the RAS; drug toxicity depresses the cerebral cortex diffusely and the effect will last until the drug is metabolized
the _______ (cerebral cortex/brainstem) more vulnerable to anoxic, ischemic, and metabolic insults.
cerebral cortex
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?
coma due to systemic metabolic disease
list some major etiological causes of coma due to decreased cerebral perfusion or hypoxemia.
myocardial infarction, cardiac arrhythmia
what are the absolute minimum requirements for consciousness?
- ) intact RAS
- ) partially functioning cerebral cortex of at least one hemisphere
- ) adequate metabolic milieu
fill in the blank: patient may be declared brain dead if comatose and lacking any signs of active brainstem reflexes including ________.
positive apnea test, no activity on EEG, no intracranial blood flow
you perform ice water calorics on comatose patient with intact MLF (intact brainstem). what do you expect to see?
eyes would deviate toward side of ice water irrigation and the nystagmus response is lost.
you perform ice water calorics on patient. ipsilateral eye ABducts but contralateral eye does not ADduct. what does this indicate?
INO–lesion between abducens nucleus in pons and oculomotor nucleus in midbrain
where is the lesion in locked in syndrome?
lesion at the caudal pons/proximal medulla
true or false: the RAS and cerebral cortex are dysfunctional in locked in syndrome.
false, they are intact
describe the clinical presentation of locked in syndrome.
patient is awake, aware, has wake/sleep cycles, but has complete paralysis except for eye movements and blinking.
in what condition does delirium most often present?
metabolic encephalopathies, but also in structural brain lesions and infections
list three mechanisms which can result in coma.
- ) supratentorial mass lesion affecting RAS
- ) subtentorial lesion afecting RAS
- ) diffuse or multifocal dysfunction
what is the most likely vascular cause of coma?
ischemic infarction of the brainstem–implicates the vertebrobasilar arterial system
there is _____ (rarely/almost always) focal neurologic deficit in patient with metabolic coma.
rarely
there is _____ (rarely/almost always) focal neurological deficit in patient with structural brain induced coma.
almost always
how does vegetative state differ from coma?
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
patient in coma has pupils equally reactive to light. suggests which type of coma?
toxic-metabolic coma
what is the first step in evaluating an unconscious patient?
see if the patient responds to your voice
presence of DTRs in unresponsive patient indicates?
nothing about the cause of the coma
