Stupor and Coma Flashcards
1
Q
What is consciousness? Requirements?
A
- total awarness of self and environment
- arousal (alertness)
- awareness (sum of cognitive mental functions)
2
Q
consciousness depends on?
A
- arousal of cerebral cortex by brainstem ascending reticular activating system (RAS)
- input from sensory
- projects to hypothalamus, thalamus, cortex
3
Q
impaired consciousness means?
A
- diffuse or b/l impairement of both hemispheres
- failure of brainstem ARAS
- both
4
Q
confusion–what is it?
A
-orientation disturbed
5
Q
delirium–what is it?
A
-hallucinations (visual)
6
Q
obtundation–what is it?
A
-mental blunting, increased sleep, arouses to mild stimuli (voice)
7
Q
stupor–what is it?
A
arouses only to noxious stimuli and not environmental
-only rudimentary awareness (purposeful motor responses)
8
Q
coma–what is it?
A
-unarousable, unresponsive, unaware
9
Q
persistent vegetative state
A
- arousal, awarness
- no reproducible response to stimuli
- eyes may be open, eye movements
- BP/pulse stable
10
Q
akinetic mutism
A
-no spontaneous motor activity
11
Q
locked in state
A
- normal sensation/ cognition
- complete paralysis except vertical eye movements
12
Q
hypertension–consider
A
-pheochromocytoma, drugs, increased ICP
13
Q
hyperthermia consider
A
-infection, heat stroke, serotonin syndrome, pontine hemorrhage
14
Q
breath odor–musty
A
hepatic failure
15
Q
neuro exam–2 purposes
A
- determine location and nature causing the impaired consciousness–anatomic level of brain involvement (supratentorial, subtentorial, diffuse)
- narrow differential possibilities
16
Q
broad categories of lesions that produce coma
A
- supratentorial mass lesions–cause dysfunction in upper ARAS, cause downward herniation of brain to compress ARAS
- infratentorial mass lesions–involve brainstem
- diffuse/multifocal brain disease
17
Q
supratentorial causes of coma
A
- unilateral–subdural hematoma, brain abcess, tumor
- bilateral–subarachnoid hemorrhage, multiple infarcts, cerebral edema, acute hydrocephalus
18
Q
subtentorial causes of coma
A
- central pontine myelinolysis
- cerebellar hemorrhage/infarct, neoplasm, abcess
19
Q
diffuse causes of coma
A
-hypoxia
-meningitis/encephalitis
-hypo/hyper-glycemia
-hyponatremia
-hepatic failure
-malignant hypertension
seizures (status epilepticus)
20
Q
Neuro exam–essential elements
A
- pupillary responses
- corneal reflex
- extraocular movements
- cough/gag reflex
- motor responses
- resp pattern
21
Q
Neuro exam–nearly essential elements
A
- neck stiffness
- carotid auscultation
- fundoscopic exam
22
Q
pupillary response–sympathetic path
A
- hypothalamus
- lower cervical cord
- sympathetic chain
- superior cervical ganglion
- up carotid artery to CN V1, long cilicary nerve (dilator)
- Mueller’s muscle
23
Q
pupillary response–parasympathetic path
A
- upper midbrain (edinger westphal nucleus)
- CN III
- ciliary ganglion
- short ciliary nerve (constrictor)
24
Q
symp and parasymp pathways for pupillary response–anatomically adjacent to?
A
- ARAS
- absent or unequal responses imply brainstem lesion!!
25
dilated pupil on 1 side
-parasymp (CN III)
26
dilated pupil bilaterally
- b/l lesion to CN III
- post ictal
- barbiturate intoxication
27
constricted pupil
-symp dysfunction
28
pinpoint pupil
- pontine lesion
- opiates
- pilocarpine (3Ps)
29
midposition and unreactive pupil
symp and parasymp (midbrain)
30
frontal gaze, pontine gaze
- frontal--deviate eyes to opp side
| - pontine--deviate eyes to same side
31
roving--conjugate, dysconjugate
- conjugate--brainstem intact
| - dysconjugate--brainstem lesion
32
conjugate deviation at rest--hemispheric lesion
- destructive--toward lesion
| - irritative-away from lesion
33
conjugate deviation at rest--brainstem lesion
-destructive--away from lesion
34
oculocephalic maneuver (dolls eyes)
Mid pons!
- CN 3,4,6
- horizontal/vertical head rotation--eyes move opposite
35
caloric (oculovestibular) reflex
```
Lower pons!
-irrigate TM with cold water
-eyes deviate to irrigated side
-eye deviate downward if b/l irrigation
(brainstem intact!)
```
36
decorticate?
arms flexed, legs extended
| -hemispheric/ corte lesion
37
decerebrate
all extremities extended
| -brainstem
38
flaccid?
pontomedullary or metabolic
39
Cheynes Stokes
- b/l hemispheres or diencephalon
| - crescendo-decrescendo breathing pattern--hyperpnia alternating with apnea
40
stupor and coma--4 broad categories
- supratentorial
- subtentorial
- diffuse/metabolic
- psychiatric unresponsiveness
41
supratentorial mass lesions--characteristics
- focal!
- neuro signs--1 anatomic location
- progression of signs rostral to caudal
- motor signs--asymmetric
42
herniation syndromes caused by?
expanding supratentorial mass lesions
| -displace brain tissue--rostral to caudal progression
43
uncal transtentorial
uncus under tentorium
| -compress CN III, contralateral brainstem (ipsilateral hemiparesis), resp abnormalities
44
central transtentorial
herniate into foramen magnum
| -resp arrest, death
45
cingulate gyrus
-herniates under falx
46
subtentorial mass lesions characteristics
- localizing brainstem signs preceed coma--always include oculovestibular abnormality (eye movement)
- CN palsies usually present
- bizarre respiratory patterns
47
diffuse/metabolic characteristics and causes
- confusion, stupor precede motor signs
- motor signs symmetrical
- pupillary reactions preserved!!
- asterixis (liver flap-flaps wrist down and up), myoclonus
- acid-base imbalance
```
hepatic/renal failure
-hyper/hypoglycemia
-hypoxia
electrolyte imbalance--hyper/hyponatremia, calcium
-sepsis
```
48
global cerebral ischemia
- blood flow inadequate to meet metabolic requirements of brain (cardiac, pul arrest)
- ranges from reversible to brain death
49
global cerebral ischemia reversible when?
-
50
prolonged ischemic episodes
- comatose at least 12 hours
| - lasting focal or multifocal motor, sensory, cognitive deficits
51
persistent vegetative state
- awake but functionally decorticate, unaware of surroundings
- eye opening, eye movements, sleep-wake cycles
52
brain death definition
- irreversibility
- complete cessation of brain function (including respirations but not heartbeat)
- persistance
53
irreversibility--what must be ruled out?
-cause of coma known--irreversible
| sedative intoxication, hypothermia (
54
cessation of brain function
- unresponsiveness to all sensory input
| - absent brainstem reflexes--respiratory responses absent 8-10 minutes after patients pCO2 rises to 60 mmHg
55
absent brainstem reflexes
- pupillary light reflex-2,3
- dolls eyes, cold water irrigation--3,6,8
- pain reflex, pinch supraorbital n--5,7
- corneal reflex--5,7
- gag reflex--9,10
56
brain death--persistence
- 6 hours with confirmatory isoelectric (flat) EEG
- 12 hours without confirmatory EEG
- 24 hours for anoxic brain injury without confirmatory EEG
57
manage comatose patients--1st steps
- A-patent airways
- B-breathing, oxygenation
- C-circulation, bleeding
58
manage comatose patients--next steps
- history, exam, EKG
- glucose, thiamine
- antidote
- adjust body T
- control agitation
- stop seizures if present
59
manage comatose patients--Lab evaluation
- venous blood--glucose, electrolytes, BUN/creatinine, osmolality, drug screen, liver function, ammonia, coagulation studies, blood cultures
- arterial blood--pH, pO2, pCO2, HCO3, HbCO
- urine--UA, culture, drug screen
- if febrile--blood cultures
- if stiff neck--LP after CT
60
manage comatose patient--diagnostic testing
- non-contrast CT (blood, space occupying lesion)
- LP (xanthochromia--hemorrhage, infection)
- MRI (posterior fossa, infarct)--not done right away!
- EEG--if expect seizures
61
manage comatose patient--specific interventions--reduce elevated intracranial P
- elvate head of bed
- intubate/hyperventilate to PCO2 of 20 mm (constricts BVs)
- mannitol for ischemic lesions (hyperosmolar conc--will suck water/edema out of brain)
- decadron for tumor, abcess, cerebral hemorrhage
- Lasix--for dehydration
62
manage comatose patient--specific interventions--treat seizures
- lorazepam
| - phenytoin
63
glascow coma sclae
(3-15)
- eye opening--1-4
- best verbal response-1-5
- best motor response-1-6
64
KEY to accuracy in diagnosis and management lies in 2 steps
- physical signs--determine anatomic level of brain involvement
- determine supratentorial, subtentorial, or metabolic
