Neuro Flashcards
Meninges
protects CNS
* Dura
* Arachnoid
Pia
Where is the epideral space
between skull bone and dura
Where is the subdural space
between dura and arachnoid
Where is the subarachnoid space
between the arachoid and pia
Compare the two ruptures in the dura mater
- Epidural hematoma (Arterial)
- Subdural hematoma (Venous)
What are the components of the arachnoid?
- CSF circulates here
- cerebral vasculature
if ruptured –> subarachnoid hemmorhage
What is the purpose of arachnoid villi?
Absorb CSF for removal
What happens if you block the arachnoid villi?
communicating hydrocephalus
What is the pia mater responsible for?
production of CSF
Cerebrospinal fluid (CSF)
Characteristics
- clear, colorless
- flows through subarachnoid
- shock absorber / brain tissue protector
* contains glucose
What does the circle of willis do?
circulates blood anterior to posterior
What are the three components of intracranial pressure?
- Blood
- CSF
- Brain tissue
Monro-Kellie Doctrine
Define
- ability for brain to self regulate
- increase in one, other one or two should compensate by decreasing
Cerebral Blood Flow
Autoregulation
changes the diameter of blood vessels
* vasocontriction = less blood flow
* vasodilation = more blood flow
What activities can cause impaired autoregulation?
coughing, suctioning, restlessness
Cerebral perfusion pressure
Define; Values (formula)
represents adequacy to delievering oxygen to the brain
60-100mh normal
50-70 adequate with injury**
MAP-ICP = CPP
MAP 50-150
* increase in MAP = constriction
* decrease in MAP = dilation
Metabolic autoregulation
- increase CO2+Lactic = vasodilation
- decrease CO2 = vasoconstriction
CSF regulation
increase ICP –>
CSF will be displaced into spinal canal –>
aarachnoid will increase absorption
Cerebral edema
water in cells cause swelling
* cause by brain trauma, CNS infection, tumors, CVA
* impairs circulation leading to hypoxia
Central Herniation
Define
Displacement of brain tissue
* leads to ischemia/anoxic injury
Central Herniation
Symptoms
Bilateral pupil dilation
Cushings triad
Flaccid paralysis
Cushings triad
- increased pulse pressure
- bradycardia
- abnormal respiration
When are intracranial pressure monitoring devices contraindicated?
GSC 9-15
(mild to moderate brain injury)
ICP monitoring
Complications
infection
obstruction
hemorrhage
misplacement
Three themes of caring for neuro patients
- Neuro exam (baseline AxO)
- ICP with its factors
- Interventions/meds
Space occupying lesion
- tumor
- abscesses
- bleeds (hemmorrhage)
Subarachnoid Hemmorhage
Cause?
caused by ruputured aneurysm
BLOOD IS NOW MIXING WITH CSF IN SUBA
Subarachnoid Hemorrhage
Clinical Manifestations
* worst headache of my life*
* decreased LOC
* stiff neck, photophobia
* Positive Kernig’s/Brudzinski’s
Kernig
painful knee extension
Brudzinski
neck flexion –> knee flexion
Subarachnoid Hemorrhage
Diagnostics
CT scan
* If negative –> LBP
* LBP + if bloody CSF
* Angio then needed for location
Subarachnoid Hemorrhage
Clinical management Pre-op
Prevent rupture
* prevent valsalva (miralax)
* antihypertensives
* antipyretics
* minimal simulation
Subarachnoid Hemorrhage
surgical management
clipping is gold standard
coiling
Subarachnoid Hemorrhage
Post-op
Prevent vasospasms
(AEB) change mental, blurred vision
decreases in CBF –>
decrease o2 –>
increase lactic acid
Subarachnoid Hemorrhage
Management of vasospasms
Nimodipine –> watch for hypotension
Triple H therapy
(hypervolemic, hemodilution, HTN)
Levophed triple H parameters
BP >20mm over baseline
(under 200)
Subarachnoid Hemorrhage
Hydrochepalus
blood clot in sub A
obstructs villi reabsorption
communication hydrocephalus
SHUNT!!!!
Tramatic Brain Injury
Primary vs Secondary
Primary –> direct force
Secondary –> biochem changes, inadequate perfusion, hypoxia
With all head injuries, what should also be assessed?
cervical spine
An increased GSC is indicative of?
Improvement
Secondary injury
Cause
ischemia
hypercapnia
cerebral edema
sustained hypertension
Secondary Injury
Increase brain tissue
Ischemic cells swell increasing tissue mass
Secondary Injury
Increase CBF
Vasodilation occurs to supply oxygen to cells
Hypercapnia from hypoventilation of unconscious patient (CO2 potent cerebral vasodilator)
HTN increases intracranial blood volume
Nursing interventions to prevent secondary injury
DO
- minimal stimulation
- head / neck neutral position
- maintain o2
Nursing interventions to prevent secondary injury
DO NOT
- do not cluster care
- no tendelenburg
- no valsalva
Compound fracture
open
Displaced fracture
closed
Linear fracture
depressed-bone fragments
Basilar Skull Fracture
Define
linear or displaced
Basilar Skull Fracture
Assessment/intervention
- assess extraocular movement
- Assess CSF drainage
- Avoid nasogastic/trach suctioning
Basilar Skull Fracture
Clinical manifestations
- otorrhea (CSF in ear)
- Rhinorrhea (CSF in nose)
- Ecchymosis –> battle’s sign(bruising behind ear)
- Ecchymosis –> raccoon eyes (raccoon)
Halo sign
CsF leakage, yellow fluid with blood inside
assess glucose
assess beta 2 transferrin
Basilar Skull Fracture
Treatment
spontaenous healing
loose gauze dressing
cranial/neuro assessment
Concussion
Definition
alteration in mental status resulting from trauma
high school football
Concussion
Clinical manifestations
- Loss of conciousness
- Retrograde amnesia(before)
- Anterograde amnesia (after)
- sluggish
- concentration issues
Concussion
treatment
rest the brain
(avoid stimulus)
Concussion
Post concussion sundrome
6mo-5yr
Contusion
Brain bruise
coup-contrecoup
complication –> expansion of hematoma, cerebral edema
Epidural hematoma
Definition
collection of blood between dura/skull resulting from laceration of meningeal artery
low or high impact injuries
Epidural hematoma
Clinical manifestations
- temporary skull fracture
- rapid decrease in conciousness (talk and die)
- uncal herniation
* IPSILATERAL PUPIL DILATION
Epidural hematoma
Treatment
Burr holes
Subdural hematoma
Define
accumulate venous blood below dura
Elderly/ETOH abusers
Subdural hematoma
Clinical manifestations
- headache
- lethargy
- confusion
- seizure
Compression of CNIII causes
increased ICP
dilated pupils
Compression of visual pathways
Increased ICP
- decreased acuity
- blurring
- diplopia
Increased ICP
interventions to decrease brain tissue volume
Mannitol
draws fluid from brain
serum osmo goal <320
Watch for hypovolemia
What fluid do you NEVER give neuro patients?
hypotonic
Increased ICP
decrease cerebra blood flow
- hyperventilation
- hypothermia
- Barbiturate coma
Increased ICP
decrease CSF
- Furosemide
- Ventriculostomy (EVD)
Level of conciousness
awareness/arousal
Posturing
Decorticate
hands to chest
Posturing
Decerebrate
hands straight out
Increased ICP
Doll’s eye Test
- cervical spine first
oculocephalic relflex
Increased ICP
Cold calorics
oculovestibular
confirm tympanic membrane intact
Determination of brain death
- CTA, EEG
- exclude endocrine imbalance
- exclude drug intoxication
- core body temp > 32 or 90f for apnea test
- Absence of motor response
- Absent reflexes
- loss of centrally controlled beathing
Cranial nerve III
corneal reflex
Cranial nerve IX/X
no cough/gag
