Disorders of consciousness Flashcards
ARAS input
visual, auditory, sensory
arousal
overall state of activity
lethargy
slight reduction in alertness
obtunation
moderate reduction in alertness
delirium
sudden disturbance in consciousness and mental function
stupor
respond only to vigorous stimuli
altered mental status
imprecise term for any of the descriptors
2 main mechanisms of coma
diffuse insult to both cerebral hemispheres
disruption on the ARAS in the midbrain and pons
coma characteristics
no awareness, no sleep cycle or purposeful behavior
vegetive state characteristics
sleep wake cycles only
minimally conscious state
sleep wake cycles, partial fluctuating awareness, reproducible purposeful behavior
locked-in syndrome
sleep wake cycles, awareness and movement is limited to eye movements
diagnostic workup for disorder of consciousness
blood tests, IV access, hook up to monitor, administer oxygen
which things should be checked and treated immediately
hypoglycemia: dextrose 50% IV
thiamine for alcoholic
Naloxone for drug overdose
small pupils
opioid toxicity and pontine lesion
midsize pupils, unresponsive to light
midbrain lesion
maximally dilated pupils
drug toxicity- anti-cholinergic overdose
mixed and dilated pupils
CN III lesion from uncle herniation
Decorticate posturing
flexor posturing (flex UE, ex LE)
lesion of the internal capsule and rostral cerebral peduncle
causes of decorticate posturing
brain tumor, stroke, drug use, poisoning, infection or liver failure
decerebrate posturing
Extensor posturing
midbrain and rostral pons
causes of decerebrate posturing
can be reversible metabolic dysfunction
hypoglycemia and hepatic encephalopathy
causes of abrupt onset unconsciousness
SA hemorrhage, brainstem stroke, intercerebral hemorrhage
what does papilledema on fundoscopic exam point towards
subhyaloid hemorrhage
corneal sensitivity bilateral loss
large pontine lesion or deep coma
corneal sensitivity unilateral loss
ipsilateral pons or trigeminal defect
positive oculocephalic reflex
eyes move opposite the rotation of the head
negative oculocephalic reflex
eyes stay midline
negative oculocephalic reflex points toward
severe brainstem dysfunction
Cheyne stokes respiration
deep breathing alternate with periods of apnea
Cheyne stokes respiration meaning
bihemispheric or diencephalic disease or metabolic disorders
Central neurogenic
hyperventilation meaning
lesions of brainstem tegmentum
apneustic breathing
prominent end-inspiratory pauses
apneustic breathing meaning
damage at pontine level, basilar artery occlusion
ataxic breathing
irregular/deep and shallow breathing randomly occurring
ataxic breathing means
lesions of lower pontine tegmenjtum and medulla
Kussmaul breathing
deep labored breathing
Kussmaul breathing means what
severe DKA
CT of the head
urgent, non-contrast
immediate neurosurgical intervention is needed for ____
intracranial hemorrhage, brain herniation, structural lesions
CT angiogram is used to
rule of basilar artery occlusion
when is EEG performed
suspected non-convulsive status epilepticus
