coma Flashcards
sleepy but easily aroused
lethargy
excessively sleepy but normal cognition when awakened
hypersomnia
metnal blunting, decreased alertness
obtundation
eyes open only briefly, after vigorous stimulation, before returning to deep sleep. cognition impaired
stupor
EYES remain CLOSED after vigorous stimulation
coma
disoriented, misperception of sensory stimuli, hallucinations. vacillates between quiet, sleepy periods, and hyper-vigiliance/agitation
delirium
awake but apathetic, no spontaniety. With vigirous stimuation, cogintive function may be normal (bilateral, fronta lobe disease, lobotomized)
abulia
silent, alert-appearing immobility. No mental activity w/vigourous stimulation (disease of frontal lobes and hypothalamus)
akinetic mutism
fragments of awareness
minimally conscious state
awake, no awareness or meaningful interaction w/enviroment
vegetative statte
two comonents of consiousness
arousal(sleep-wake cycle) and content (aware of self and environment)
disease in content of consicousness –>
dementia
disease in arousal —>
stupor and coma
sleeping sickness pts had lesions in which area of brain?
ROSTRAL periaqueuductal gray and posterior 3rd ventricle.
involuntary loss of muscle tone during emotional exictement
cataplexy
lesion of which hypothalamic nucleus –> profound insomnia?
ventral lateral preoptic nucleus
nuerons in which hypothalamic nucleus producing which neurotransmitter are lost in narcolepsy?
lateral hypohtalamus - neurons producing orexin.
lesions of brainstem do not affect wakefulness, as defined by EEG pattern unil lesion reaches which area?
upper pontine and midbrain level
which area of the brain mediates arousal?
reticular activating system
t/f. regions confined to the upper pons can cause coma even in the absence of midbrain and thalamic injury
true
which lesion causes locked in syndrome in which a patient in which corticobulbar and cortciobulbar tracts disrupted bilaterally –> pt = quadraplegic, can’t speack, swallor or breathe on own, paralyzed lower face, yet PT is CONSCIOUS, AWARE AND CAN SEE AND HEAR AND BLINK
CAUDAL PONTINE HEMORRHAGE
what is located in the intralaminar nuclei of the thalamus, the tegmentum of midbrain, and tegmentum of upper 1/3 pons. (close to medial temporal lobe and tentorium cerebelli)
reticula activating system.
note: RAS not SOURCE of arousal; ascending arousal system is.
nucleus that promotes sleep and secretes GABA and galanin?
ventro-lateral preoptic nucleus (inhibits ascending arousal system)
how do GABA enchancing ETOH and benzodiazepam affect VLPO?
promote its inhibitory affect.
3 structural causes of coma? (HIS)
acute obstructive hydrocephalus
Infratentorial mass lesion
supratentorial mass lesion
2 metabolic causes of coma?
reversible injury (sedative overdose)
irreversible injury(hypoxia in cardiac arrest)
rule out psychogenic coma first
transtentorial herniation of medial temporal lobe or uncus may trap which two structures?
CN3 and posterior cerebral artery
rupture middle meningeal artery –>______–>transtentorial herniation of medial temporal lobe
epidural hematoma
what lies btw an herniating uncus and midbrain and diencephalon
CN3 (compressed 1st b4 pressure on midbrain and dienchephalon produce ischemia
dilated pupil not reactive to light may be 1st sign of ______
increased ICP caused by uncal herniation,
pressure against midbrain from GBME causes ischemic hemorrhagic necrossi known as
Duret’s hemorrhage
CN3 rests of which medial temproal lobe structure?
uncus
which artery can be crushed when brain is pushed under falx cerebri(falcine herniation)?
anterior cerebral artery
which herniation is described?
- rostral –> caudal deterioration (diencephalon-thalamus +hypothalamus)–>midbrain failure
- reduced consicousness
- small reactive pupils b/c central sympathetic tracts coming from hypothalamus compromised—>herniation spreads to midbrain and pupils FIXED in mid position
- decorticate (FLEXOR posturing)
–CHEYNE STOKES respiration = apneic spells intersepred w/hyperventilation (early warning sign of hernination)
late signs: decerebrate of extensor posturing + pupil fixed in mid position
-
-
CENTRAL HERNIATION
late signs of central herniation (bascially brain herniates under falx cerebri = falcine herniation)
- decerebrate posturing - extensor posturing
- pupil that cannot constrict anymore - remains fixed in midposition
apneic spells, interspersed with hyperventilation period and are ealry sign of herniation = ________
Cheyne-Stokes respirations
Infratentorial lesions:
- intrinsic = name 2
- extrinsic that compress brainstem name 3 (HIB)
intrinsic: top of basilar atery ischemic stroke and pontine hemorrhage
extrinsic:
1. cerebellar hemorrhage
2. cerebellar infarction
3. cerebellar brain tumor
primary brain stem lesions cause which 4 symptoms:
- segmental CN deficicity
- ascending (spinothalamic tract) dysfunction
- descending (corticospinal, central, sympathetic), tract dysfucntion
- early cerebellar signs
describes what:
abrupt COMA w/PINPOINT PUPILS
decerebrate (extensor posturing)
flaccid quadraplegia
horizontal gaze paresis
ocular bobbing
when pt awakes, at risk for what?
PONTINE HEMORRHAGE
pt at risk for: LOCKED IN SYNDROME
which 2 endogenous and 3 exogenous toxins interfere w/metabolism of cerebral cortex and rostral brain stem AAS?
endogenous: UREMIA and hepatic failure
exogenous: drug overdose, poisons, sepsis
hypoxia, hyperglycemia, hypo/hyper osmolality and electrolyte acid-base imbalance all cause
metabolic enchephalopathy
metabolic insult to brain is G____, D______.S _______
global, diffuse, symmetric
neuro exam in metabolic encephalopathy?
NON-FOCAL. lateralizing signs such as hemiparesis are absent or minimal
head CT positive/negative in metabolic encephalopathy
negative
pupils in metabolic encephalopathy? what are rare exepctions (BAG3)
PUPILS STAY REACTIVE even as other brainstem reflexes are lost
rare excpetions: atropine, botulims, glutethimide
asterixes, multifocal myoclonus and tremor all signs of :
metabolic encephalopathy
t/f. stupor and coma are reversible w/metabolic correction and ICU support.
true
3 causes of delirium in elderly?
dehyration, drug intoxication, and sepsis
t/f. metabolic encephalopathy can unmask old lesion from stroke?
true (use old CT and MRI to date structural lesion)
cheyne stokes respirations can be a sign of _______
herniation: central or tentorial
in psychogenic coma, what will ice-water calorics induce?
nyastgmus
can a coma pt open their eyes
no
are vital signs normal in coma
no
Diabetes, renal failure, alcoholism, and drug abuse can all cause
metabolic encephalopathy
presence of retinal venous pulsations meas what?
NO raised intracranial pressure
if oculocephalic and oculovestibular responses are intact, what is likely?
brainstem is preserved.
3 noxious stimuls used to arouse pts who do not respond to voice command?
supraorbital pressure, nailbend pinch, sternal rub
why was glasgow coma scale developed?
for prognosis in head trauma
flexor response to a pin prick means that what has been lost regarding motor centers (decorticate posturing is due to) __________ ?
cortical control of brain stem motor centers
extensor resonse (decerebrate posturing) arises w/ what?
loss of red nucleus and rubrospinal tract in the midbrain
chain of trying to get coma pt to respond:
voice command –> painful stimuli (finger nail bed, supraorbital pressure, sternal rub) –> flexion posturing( pt has lost cortical control of movement, but midbrain intact) –> extensor(midbrain lost- extensor dominant tracts w/start in pontine region take over) –>NO RESPONSE( severe hypotension or hypoxia) .
prognosis of pt w/glascow score of: 3,8, 12 or better
3= death
12 or greater = good prognosis
8 = nursing home care
what would you use to dx infectious and inflammatory cuases of coma?
CSF studies
pt in coma tx:
- oxygenation
maintain glucose
lower ICP (hyperventilation + mannitol)
stop seizures
treat infection
restore A/B and electrolytes
Adjust body temp
give thiamine
antidotes(naloxone, flumazenil)
control agitation
in non-traumatic coma, absence of _which 2 relfexes____ at 3 days carries poor prognosis
pupillary light reflex and corneal reflex
in hypoxic coma, absence of ______ motor movements at day 3 carries poor prognosis
purposeful motor movements
what is described below :
normal vital signs
normal neurological disease
resistance to eye opening
oculocephalic (doll’s eyes) absent due to visual fixation
induction of nystagmus w/ice-water calorics
psychogenic coma
vertebrobasilar artery thrombosis and massive infarction in anterio pons can cause _____
locked in syndrome
which nerve affected by ruptur of PCOM aneurysm, medial temporal lobe herniation?
CN 3 = oculomotor. dilated pupil early in disease.
how would a pt on phenobarbital OD present?
depressed vitals including temperature, respiration, HR, BP
tx: ICU supportive care–> pt will make full recovery
