Neuro Flashcards
(160 cards)
1
Q
what does the CNS comprise of?
A
brain & spinal cord
2
Q
what is the largest & most complex part of the CNS? what 4 parts if it comprised of?
A
the brain! comprised of:
1. skull (cranium)
2. meninges
3. ventricular system
4. cerebral vasculature
3
Q
what are the main roles of the skull & facial bones?
A
protect the brain from traumatic injury
4
Q
what is the difference between the superior services & basilar services of the skull?
A
Superior services: smooth
basilar: contain ridges & folds w sharp edges
5
Q
what is the role of the meninges & what three layers does it consist of?
A
form of another source of protection for the CNS
three layers:
1. dura
2. arachnoid
3. Pia
6
Q
what are the spaces between the meningal layers called? there’s 3 of them
A
- epidural space (between skull bone & dura)
- subdural space (between dura & arachnoid)
- subarachnoid space (between the arachnoid & pia)
7
Q
what is the dura mater? where does it get its main blood supply from?
A
outermost layer of the meninges that is directly beneath the skull; middle meningeal artery
8
Q
what can a rupture of the middle meningeal artery result in?
A
epidural hematoma (space between the dura mater & skill bone –> epidural space)
9
Q
what can a rupture of the intercranial & meningeal veins result in?
A
subdural hematoma (bleeding in the subdural space underneath the dura)
10
Q
what is the arachnoid mater? what does it connect to?
A
2nd layer of protection in the meninges; delicate, fragile membrane that surrounds the brain (connects to the pia mater)
11
Q
what is the subarchnoid space between?
A
arachnoid mater & pia mater in the meninges
12
Q
where does CSF circulate freely?
A
subarchnoid space
13
Q
what does rupture of an artery causing mixing of blood w the CSF cause?
A
subarcahnoid hemorrhage
14
Q
what is the arachnoid villi? what does it absorb?
A
small profusions in the arachnoid mater (absorbs CSF for removal via the venous system)
15
Q
what does blockage from a subarachnoid hemorrhage causse?
A
communicating hydrocephalus
16
Q
what is the pia mater? what is its role?
A
final / third layer of meninges; applies large volume of arterial blood to the CNS, forms the choroid plexus within the ventricles which are responsible for the production of CSF
17
Q
lateral ventricles located within the hemisphere of the cerebral cortex extend to form what?
A
frontal horns located in the frontal lobe
18
Q
what are ventricles?
A
a network of cavities that are throughout the brain
19
Q
which ventricles are responsible for the production & distribution of CSF?
A
choroid plexus
20
Q
what does blockage of CSF production / distribution cause?
A
non-communicating hydrocephalus (build up of fluid in the brain)
21
Q
what absorbs CSF?
A
arachnoid villi
22
Q
CSF functions as a ____ & protects brain tissue from bony structures
A
shock absorber
23
Q
what does the CSF contain?
A
glucose, amino acids & other nutrients needed by CNS cells
24
Q
what is the CSF a poor source of?
A
O2 because it does not have hemoglobin or blood in it (if it does, this is BAD & not normal!)
25
what are the two sets of vessels that supply the brain?
internal carotid arteries & vertebral arteries
26
where do the internal carotid arteries supply blood to?
to the cerebrum & external supply to face & scalp
27
what do the two vertebral arteries form?
the basilar artery
28
how do the vertebral arteries help complete the circle of willis?
dives into the two posterior cerebral arteries
29
what is the main role of the circle of willis?
allows for collateral circulation if one vessel is occluded; permits blood to circulate from one hemisphere to the other
30
what should you expect to find in the CSF?
glucose
31
ICP is defined as....
the pressure in the cranial vault relative to atmospheric pressure
32
where is blood supplied from in the brain?
internal carotids & basilar arteries
33
what are the main roles of CSF?
production, circularization & reabsorption
34
what takes up the most space in the brain?
brain parenchyma (brain tissue or brain tissue volume)
35
what is the Monro-Kellie Doctrine?
the ability of the brain to self-regulate (increase in volume of one intracranial component must be compensated by a decrease in one or both of the other components so that the total volume remains fixed)
36
if the monro-Kellie doctrine does not occur, what does this cause?
increase in ICP
37
what is the importance of autoregulation relating to cerebral blood flow?
ability of an organ maintaining consistent blood flow to spike marked changes in BP & metabolic conditions; ensures a constant blood flow through the cerebral vessels over a range of perfusion pressures (brain's protective device against the fluctuating changes in BP)
38
describe cerebral blood flow changes by both vasoconstriction & vasodilation
vasoconstriction = LESS blood flow will occur
vasodilation = MORE blood flow will occur
39
any activity that causes an increase in BP can also increase which two other things?
give examples
cerebral blood flow & ICP
EX: coughing, suctioning, or restlessness
40
what is cerebral perfusion pressure?
provides the adequacy of the cerebral circulation in delivering oxygen to the brain tissue
41
what is normal CBF affected by?
CPP
42
what is the formula for calculating CPP?
MAP - ICP = CPP
43
what are two things that really affect our cerebral blood flow?
1. BP
2. CO2
44
pressure auto regulation occurs when the MAP is within what range?
50 - 150 mm Hg
45
what does an increase in MAP indicate?
cerebral vasoconstriction (decrease in blood flow)
46
what does a decrease in MAP indicate?
cerebral vasodilation (increase in blood flow)
47
if there is an increase in CO2 & lactic acid, what does this cause in the brain?
vasodilation
48
if there is a decrease in CO2, what does this cause?
vasoconstriction
49
CO2 causes the brain to _____ which causes more ______
vasodilate; cerebral blood flow!
50
if there is an increase in ICP, what will happen?
CSF will be displaced into the spinal cord & the arachnoid villi will increase absorption to make more room for cerebral blood flow or the brain tissue itself
51
what are some things that can result from increased ICP? list 6
head injury (issue w cerebral blood flow or brain tissue volume)
bleeding in brain (issue w cerebral blood flow)
tumors (issue w brain tissue volume)
infections (issue w the CSF)
extra fluid in brain (issue w brain tissue volume)
strokes (issue w cerebral blood flow or brain tissue volume depending on type of stroke)
52
what are three things that affect ICP?
cerebral blood flow, CSF & brain tissue volume
53
what does cerebral edema affect in the brain?
brain tissue volume (water in the cells)
54
what can cerebral edema be caused by? list 4
brain trauma, CNS infections, brain tumors & CVA's
55
what can cerebral edema lead to?
secondary complications such as hypoxia
56
out of the two types of cerebral edema, which one is most common?
vasogenic (often caused by brain tumors or cerebral accesses in surgery)
57
what can central herniation usually caused by?
cerebral edema or anything that causes an increase in ICP (bad!)
58
what is central herniation?
displacement of brain tissue through structures in the skull because of an increased ICP
59
what does central herniation lead to?
ischemic, anoxic injury because of the blood being cut off from the medulla, brain being compressed centrally therefore pushing on the brain stem
60
once compensatory mechanisms are exhausted, what are some signs / symptoms of central herniation? name 3
1. cushing triad (imminent of death!)
- increasing or widened pulse pressure
- extreme bradycardia
- abnormal resp patterns
2. **Bilateral pupillary dilation**
3. flaccid paralysis
61
what does cushing triad indicate pathologically?
indicates brainstem compression! (leading to decreased blood flow)
62
which type of patients is intracranial pressure monitoring contraindicated in?
not indicated for patients w mild to moderate brain injury (glasgow coma scale 9-15 or aware & talking)
63
which patients is ICP monitoring typically used in?
comatose patients or patients w severe brain injuries (usually Glasgow scale is 3-8 w an abnormal CT scan)
64
name 4 ICP monitoring complications
1. infection (most common because of how invasive it is)
- antibiotic prophylaxis often given
2. obstruction (you'll know if the drain stops draining or if their neuro status changes)
3. hemorrhage (not too common)
4. misplacement (if a pt pulls on it)
65
The nurse is caring for a ventilated patient post head injury. The patient’s heart rate drops from 70 to 34 and blood pressure is 205/76. The nurse suspects
cushing triad
66
what are considered space-occupying lesions in the brain?
tumors, abscesses & bleeds (subarachnoid hemorrhage, epidural hematoma & subdural hematomas)
67
describe a subarachnoid hemorrhage (SAH)
bleeding into the subarachnoid space (space between subarachnoid & pia mater)
68
what is a subarachnoid hemorrhage usually caused by?
rupture of a cerebral aneurysm
69
what is an aneurysm? what are three risk factors?
outpouching of the wall of blood vessel that results in weakening of the wall (ballooning of a blood vessel)
occurs w advancing age, stress & BP increase
70
what is the typical size of aneurysms?
2-7 mm
71
where are aneurysms usually found?
in the base of the brain on the circle of willis or on the bifurcation of blood vessels
72
what specifically can cause same side pupil dilation when there is a subarachnoid hemorrhage?
if aneurysms take awhile to rupture, they expand & place pressure on surrounding structures like the ocular motor nerve causing the same side pupil dilation
73
name some clinical manifestations of a subarachnoid hemorrhage? list 4
**- "worst HA of my life"**
- N/V
- decreased LOC & irritability
- signs of meningeal irritation (stiff & painful neck or nuchal rigidity, photophobia, blurred vision, fever, positive kernig's & bruzinski's signs)
74
what is a positive Kernig's sign? what can this indicate?
knee extension is painful & lifted to a 90 degree angle
indicates meningeal irritation & a subarachnoid hemorrage
75
what is a positive brudzinski's sign? what can this indicate?
when chin if lifted towards the chest & knees & hips flex
indicates meningeal irritation & a subarachnoid hemorrhage
76
when is a CT scan most sensitive to diagnose a subarachnoid hemorrhage?
within those first 24 hours
77
if initial CT results are negative for a subarachnoid hemorrhage, what type of procedure is done? how would a lumbar puncture show a subarachnoid hemorrhage?
lumbar puncture (CSF will be bloody if a subarachnoid hemorrhage occurred)
78
what does cloudy CSF typically indicate?
an infection such as bacterial meningitis
79
after diagnosing a SAH, which procedure is needed before surgery & why?
cerebral angiography (looks at actual vasculature & identifies exact location of SAH in prep for surgery)
80
what does SAH clinical management focus on before surgery?
focuses on preventing aneurysm from rupturing!!
81
which nursing interventions are done before surgery for SAH? name 3
minimal stimulation (quiet environment, bowel regimen to prevent straining (valslva maneuver), & limiting visitors))
82
which meds are often given before surgery for SAH?
- antihypertensives (do not want a high BP hitting aneurysm & causing it to rupture or bleed more)
- stool softeners to prevent straining
antipyretics (treat fever caused by meningeal irritation) if the aneurysm is ruptured & mixed w CSF
83
which surgery is the gold standard for SAH?
surgical clipping (once clipped the aneurysm is ruptured to decrease the size & get rid of it)
84
what other surgery is done for SAH?
coiling or GDCs (soft coils conform to the shape of the aneurysm occluding it from getting the blood flow so there is less risk of the blood flow coming up against it & causing it to rupture)
85
what is a common complication after a SAH & what are some signs / symptoms?
vasospasms (constriction of the cerebral artery)
S/Sx:
- change in LOC, lethargy, blurred vision, headache, language impairment, hemiparesis (muscle weakness on one side) & seizures
86
how does a vasospasm affect CBF & waste products?
Causes decrease in CBF resulting in decrease oxygen to brain tissue & accumulation of waste products such as lactic acid d/t lack of O2 to that part of the brain
87
which meds are given to treat / prevent vasospasms (post treatment for a pt w an SAH)? name 2
Nimodipine (causes vasodilation & keeps cerebral artery open)
- Ca channel blocker show to improve outcomes & prevent vasospasms
- watch for hypotension!
- "triple H" therapy (hypervolemic expansion, hemodilution & hypertension)
88
what does "triple H" therapy consist of?
- Hypervolemia (IV colloid & crystalloids) avoid hypotonic solutions! monitor for pulmonary edema & HF
- hemodilution (decreasing blood viscosity w IV fluids & trending the hemoglobin)
- Hypertension (Norepi; give if BP is over baseline (150-160) but < 200)
89
name 3 complications of SAH
1. hydrocephalus (build up of CSF) after SAH
- blood clots in subarachnoid space
2. seizures (blood acting as irritant to neurons)
3. rebleeding (if aneurysm is not repaired; risk of thise more within first 24 hrs)
90
if hydrocephalus develops, what type of procedure is done?
VP shunt (prevents build up of CSF)
91
The nurse is caring for a patient with a subarachnoid hemorrhage. Which of the following orders would the nurse suspect to prevent vasospasm?
Nimodipine
92
describe the difference between primary & secondary traumatic brain injuries
primary (injury occurs R/T the direct force at the time of the event)
EX: if it were a gunshot wound, it would be the actual gunshot wound itself
secondary (everything that comes after the injury or response to that injury)
EX: cerebral edema, biochemical changes, inadequate perfusion, hypoxia
93
what is the goal for TBI patients?
prevent secondary injuries
94
with all head injuries, what should be assessed for possible injury?
the cervical spine
95
if your patient falls, should you get them up right away? why or why not?
no - call for help but don't get them up if you did not witness the fall because if they hit their head & you don't know why, you may want to grab a cervical collar & protect their cervical spine before getting them back up
96
what is important to know about a gasgow coma scale?
the lower the score, the worse the patient is! severe is 3-8
97
what increases when a patient develops a secondary injury with a TBI?
ICP, cerebral edema, CBF & intracranial blood volume
98
CO2 is a cerebral ____. What can occur from hypoventilation of an unconscious patient?
vasodilator!! hypercapnia can occur from hypoventilation of an unconscious patient
99
what are some nursing interventions to prevent effects of a secondary injury & things that decrease ICP? list 9
- calm, quiet environment
- **head, neck in neutral position (promotes venous drainage decreasing the blood volume)**
- *do not cluster nursing activities (limit stimulation)**
- maintain O2
- decrease CO2 retention (want NO cerebral vasodilation)
- no tredelenburg
- no valsalva
- minimal stimulation
- visitor restriction
100
TBI skull fractures are categorized by what?
location
101
what does a compound skull fracture mean?
occurring w an open wound
102
what does a displaced skull fracture mean?
closed wound in which the edges of the fracture no longer meet
103
what does a linear skull fracture mean?
a simple crack
104
when does a TBI skull fracture typically need surgery?
when there are depressed bone fragments pushed into brain tissue
105
where do basilar skull fractures occur?
at the base or floor of the skull or middle of the anterior fossa (may be either linear or displaced)
106
the middle fossa in the skull contains which two bones?
temporal & sphenoid bones
107
the anterior fossa in the skull contains which two bones?
frontal & ethmoid bones
108
what is important to assess when detecting impingement of cranial nerves that could be affected w a basilar skull fracture?
extraocular movements (external movements of the eye)
109
what should be avoided in someone w a basilar skull fracture? why?
nasogastric & nasotrachial suctioning (increase chance of passing tube through fracture into the brain)
110
what does CSF drainage from the ear or nose indicate?
damage to the dura (typically in basilar skull fractures)
111
name 4 s/sx of a TBI basilar skull fracture?
1. otorrhea (CSF drainage from ear)
fracture in middle fossa
2. ecchymosis (bruising behind the ear; battle's sign)
could be a delayed finding
3. rhinorrhea (CSF drainage from the nose)
fracture in anterior fossa
4. ecchymosis (bruising around eyes) (raccoon eyes)
late finding
112
what is a CSF halo sign?
layering of yellow fluid w blood in the inside indicating CSF (usually on gauze)
113
how do you check for presence of CSF on a gauze?
use a glucometer (will usually come up as a normal glucose amount if it is CSF but if it is critically low, then it is not CSF)
114
what is a more effective & definitive that determines if CSF if truly on the gauze?
beta - 2 transferrin
115
what part of the brain is damaged if there is a CSF leak?
dura
116
how do you treat a CSF leak associated w a basilar skull fracture?
- will sometimes heal spontaneously
- external drainage device can be used to reduce pressure & use body's tissue to repair the dura (sometimes pt can have a ventriculostomy)
- loose gauze dressing can be applied to ear or nose to quantify amount & character of drainage
117
what should you tell a patient when you apply a loose gauze dressing to their nose for a CSF fluid leak?
tell them not to blow their nose! must not occlude, fluid needs to be able to drain
118
name some s/sx of a concussion
- LOC (does not have to lose consciousness to be diagnosed though)
- retrograde amnesia (can't remember events before)
- anterograde amnesia (can't remember events after)
- nausea
- confusion
- H/A
- dizziness
- double or blurry vision
- sensitivity to light or noise
- sluggishness
- irritability
- concentration or memory problems
- slowed reaction time
- balance problems
119
how do you treat a concussion?
rest the brain!! any stimulus, not only physical activity but participating in daily activities like texting, watching TV, reading, schoolwork can worsen the injury & extend the recovery
120
what is post concussion syndrome? how does this occur?
concussion symptoms lasting 6 months to 5 years after the initial injury (usually occurs to people who have had the repeated injuries)
121
what is a contusion? what does it result from & cause?
bruising of the brain; resulting from a laceration of the micro vasculature causing localized bleeding & is often associated w other brain injuries such as subdural hematomas & cranial fractures
122
what are 2 complications of contusions?
1. expansion of hematoma
2. cerebral edema
123
what is an epidural hematoma? what is it caused by?
a collection of blood between the dura & inside of the skull (within the epidural space)
caused by laceration of middle menigeal artery (as the artery bleeds, it pulls the dura away from the skull & creates a pouch that expands into the intracranial space)
124
what type of injuries lead to an epidural hematoma?
low impact injuries such as falls or even high impact injuries such as motor vehicle collisions
125
what are some clinical manifestations of an epidural hematoma?
- rapid decrease in consciousness ("talk & die") (pt loses consciousness but gets up & seems totally fine after a fall & doesn't get help but they deteriorate rapidly & lose consciousness again)
126
what can an epidural hematoma progress to?
an uncal herniation (temporal lobe called uncus)
causes same side pupil dilation (ipsal)
127
what type of pupil dilation do central hematomas have?
bilateral
128
how is an epidural hematoma treated?
surgical emergency (Burr holes --> holes in the brain which will help decompress pressure & remove blood)
clot is evacuated
129
what is a subdural hematoma?
Accumulation of venous blood below the dura & above the arachnoid layer & subdural space
130
which patients are at a higher risk for subdural hematomas?
elderly & ETOH abusers (higher incidence of falls & corticol atrophy --> degeneration of the cortex of the brain that increases tension on veins making them easier to rupture)
131
why may patients with subdural hematomas not be symptomatic for awhile?
it is venous blood
132
explain the 3 categories of subdural hematomas
1. acute (1-2 days)
2. subacute (2 days - 2 weeks)
3. chronic (> 2 weeks)
133
what are some clinical manifestations of subdural hematomas?
chronic may initially experience small bleeds (asymptomatic) --> typically a fall in elderly
overtime blood accumulates until neuro symptoms appear:
- H/A
- lethergy
- confusion
- seizure
134
how are subdural hematomas treated?
surgery (Burr holes to get blood out) & often a drain will be placed on the floor to get blood out through gravity (a closed system)
135
The nurse is caring for a patient after a basilar skull fracture. Which of the following is NOT an appropriate intervention for this patient?
Applying tight gauze in the nose
136
what are the treatment goals for increased ICP? name 4
1. decrease ICP
2. optimize cerebral perfusion pressure
3. maintain adequate tissue oxygenation
4. avoid brain herniation
137
what is the main goal for increased ICP?
helping the cerebral perfusion pressure
138
which med is given to decrease brain tissue volume & increased ICP? what do we want to monitor for?
Mannitol (osmotic diuretic)
watch for hypovolemia!!!
139
what is the serum osmolality goal when giving a patient mannitol? what is a pt at risk for if the level isn't within range?
< 320; if levels are > 320, pt is at risk for a kidney injury!
140
which type of fluids will you give if a pt develops hypovolemia from mannitol?
isotonic crystalloids
141
which fluids should you give if a patient has cerebral edema or their sodium is low? how should this fluid be administered?
hypertonic IVF (3% saline or NS)
**fluid should be administered slowly because of NA**
142
which fluids should you ALWAYS avoid giving to neuro patients?? why?
hypotonic IVF --> fluid would rush into the cells causing further increase in cerebral edema
143
which surgeries can be done to treat increased ICP? list 3
decompressive craniectomy --> removes a large flap of the skull & opens the dura
Hematoma evacuation --> removing the bleeding that is causing the issue
tumor removal
144
how can we treat increased ICP by decreasing the cerebral blood flow? list 11
- decreasing CO2 (increasing rate on ventilator settings)
- temperature control (hypothermia)
- patent airway --> adequate sedation & analgesia
- anticonvulsants
- barbiturate coma therapy
- preventing valsalva
- no tredelenburg
- no clustering nursing activites
- HOB elevated 30 degrees
- **head & neck in neural position (if our neck is kinked, we could have compression of the jugular vein which will lead to increased ICP)**
- minimal stimulation
145
how do we decrease CSF? two ways
1. loop diuretics (furosemide)
2. ventriculostomy (EVD)
146
what are 3 ways in general we need to do to decrease ICP?
1. decrease brain tissue volume
2. decrease cerebral blood flow
3. decrease CSF
147
what is the most sensitive indicator of increased ICP?
consciousness
148
when assessing arousal, how should you always first stimulate a patient?
calling their name
149
how is a patient's cognitive function assessed?
asking 3 orientation questions regarding person, place & time
150
how are decorticate & decerebrate posturing similar? list 3 things that are similar
feet are extended, internally rotated & plantar flexed in both!
151
what is decorticate posturing? what does this indicate?
arms, wrist & fingers are flexed (arms go to the core) indicates a problem w the cerebral hemisphere, the basal ganglia or thalamus
152
what is decerebrate posturing? what does this indicate?
arms are to the side, extension, abduction & hyper pronation of the upper extremities
usually a problem w the midbrain or pons
153
which positioning is more serious?
decerebrate!!
154
which test is used to determine brain death? explain it
doll's eyes test / oculocephalic reflex
turn the patient's head one way & ideally the eyes should turn back the opposite way
if patient's eyes don't move or doll's eyes are absent, this means significant brain death & brain stem is not intact
155
what must you always check before performing a doll's eye test / oculocephalic reflex?
check for absence of cervical spine injury prior to performing this exam as you are manipulating that cervical spine!
156
which test is used to determine brain death but must be done by a physician? explain results
cold calorics / oculovestibular reflex
administer cold water in ear via a synringe
positive (patient looks at person who is doing this or at syringe)
abnormal (eyes are just going in different directions)
absent (patient is doing nothing & has no response = indicative of brain death)
157
what should be confirmed prior to a cold calorics / oculovestibular reflex test?
that the tympanic membrane is intact
158
which brainstem reflexes are absent when determining brain death? list 4
***no cough or gag reflex*** cranial nerves IX & X
no PEERLA
no corneal reflex (cranial nerve III)
no doll's eye or old calorics reflex
159
Which of the following interventions reduces brain volume?
Mannitol
160
