CCRN Exam Neurology Concepts
LOC does not changed until the score is ___ on Hunt and Hess grading scale
3 or greater
Minimum for perfusion is
50 mmHg with elevated ICP, maintain CPP >70mmHg
What do you do after an APnea test is completed?
After 8-12 minutes, do an ABG, reconect ventilator, and interpret the test results
prevent vasospasm by providing ____
CCB nimodipine
S/S of increased ICP
Early: Change in LOC, restlessness, agitation, headache, N/V, seizures, cranial nerve palsies, visual dysfunction, papilledema, pupillary changes, motor dysfunction, Cushing's triad
L brain bleed/infarct assessment
Eyes deviae to the L, R sided weakness/paralysis, R homonymous hemianopsia, R Babinski, aphasia (expressive, receptive, or global) if L hemisphere dominant
____ is the drug of choice for blood pressure control in patients after tPA administration
Labetalol
Meds to stop seizure
Lorazepan (Ativan) Diazepan (Valium)
CPP equation
MAP-ICP CPP especially in the presence of elevated ICP, is more important than ICP alone and demonstrates the important relationship between MAP and ICP
Should hyperventilation be used to decrease ICP?
No, because it will cause alkalosis (pH will rise). This will results in cerebral vasoconstriction, which will lower ICP, but reduces cerebral blood flow
Meds to prevent seizure
Phenytoin (Dilantin) Phenobarbital
How are benzos reversed?
Romazicon
Which is worse, obtunded or stuporous?
Stuporous- patient cannot speak remember "O" comes before "S", "O" is better!
Circle of Willis definition
a circulatory anastomosis comprised of various arteries that supply blood to the brain, a well developed Circle of Willis allows collateral blood flow to one area from another area in the event of an occlusion
arteriovenous malformation (AVM)
a developmental vascular anomaly composed of a tightly tangled mass of dilated vessels that shunt arterial bloood into the venous side without the usual connecting capillaries
homonymous hemianopsia definition
a loss of vision in half the fied of each eye indicates damage to the optic nerve cranial nerve II, occurs opposite the side (contralateral) of the problem
Reticular Activating System (RAS)
a network of neurons connecting the brain stem (lower RAS) to the cortex (higher RAS)
Pontine infarct stroke characteristics
aPneustic breathing pattern, Pinpoint Pupils, Parasympathetic innervation (pontene, lose sympathetic innervation) Think "P"
epidural hematoma definition
above the dura
In the presence of elevated ICP, AVOID:
acidosis, alkalosis, hypotonic solution, hyperextension/ flexion of the neck, peep, low protein, restraints, agitation, noxious stimuli, fever
myasthenia gravis (MG)
an autoimmune attack of neuromuscular junction
muscular dystrophy (MD) definition
an inherited group of progressive myopathic disorders resulting from defects in a number of genes required for normal muscle function causes progressive msucle weakness (myopathy) and atrophy (loss of muscle mass) due to defects in one or more genes required for normal muscle function
consciousness depends on ____
an intact cerebral cortex and reticular activating system (RAS)
which arteries is the Circle of Willis composed of?
anterior cerebral artery (L and R), anterior communicating artery, internal carotid artery ( L and R), posterior cerebral artery (L and R), posterior communicating artery (L and R)
H&H Score I neuro status
asymptomatic or mild HA, slight nuchal rigidity
H&H Score II neuro status
awake, alert, severe HA, stiff neck, cranial nerve palsy (diplopia, ptosis, dilation)
Upper RAS is responsible for ____
awareness
blood supply to the brain includes the ___ and ___
basal vertebral (supplies lower areas, brain stem) carotids (supply upper areas, L internal carotid is dominant for most people)
the ____ and ____ arteries are NOT part of the Circle of Willis
basilar artery and middle cerebral arteries (MCA)
subdural hematoma definition
below the dura
if pathology on both sides, ____ Babinski
bilateral
halo sign
blood stain surrounded by a yellowish stain; highly suggestive of a cerebrospinal fluid leak
vasospasm results in ____, may be a devastating complications
brain ischemia
Obtunded LOC
can speak, mumble words
Pathophsyiology of Status Epilepticus (Late)
cerebral blood flow unable to meet demands, arrhythmias (hyperkalemia), hypoglycemia, big increase in K+ and CKs, Rhabdomyolysis (extremely high CKs), V Fib, death is due to cerebral hypermetabolism
What is the first sign of a neuro problem?
change in LOC, except for an epidural hematoma that may cause pupil changes before an LOC change
What is the first sign of increase ICP?
change in LOC, since the "higher" centers of the brain show symptoms first and then progress down toward the brain stem
Brudzinski's sign
chin to chest causes neck pain and the urge to draw knees up (meningismus)
CSF is produced in ____ and absorbed by ___
choroid plexus (4th ventricle) araachnoid villi
if the lower RAS is damaged, ____ occurs, if only the upper portion of the RAS is damaged, the patient ____
coma the patient loses awareness but still wakes up and goes to sleep
H&H Scored V
coma, posturing
motor changes are ____ side of pathology
contralateral
Babinski is ____, ___ side of pathology
contralateral, opposite side of pathology
visual changes are ____, ____ side of the pathology
contralateral, opposite side of the pathology
cerebellum function
coordination, balance, gait
Apnea test prerequisites
core temp >36.5, SBP >90, PaCO2 >35, absence of drugs to cause respiratory depression, preoxygenation prior to ventilator, disconnection fro 20 minutes at 100%, PaO2 may be normal or supranormal after preoxygenation period
Decussation
crossing of motor fibers occurs in the medulla, motor problems are contralateral to the problem
central herniation is usually due to ____, ____ development
diffuse edema, slower development
uncal herniation definition
displacement of temporal lobe (uncus) against the brain stem and 3rd cranial nerve (oculomotor, pupil)
Stuporous LOC
does not speak, moan, grimace
Apnea test negative interpretation
does not support brain death, respiratory movements observed
H&H Score III neuro status
drowsy or confused, stiff neck, mild focal neuro deficit
What neuro problem can steroid therapy prevent?
elevated ICP
uncal herniation is most often caused by ___ that occurs in temporal area
epidural hematoma
Exclusion criteria for tPA
evidence of hemorrhage, stroke or head trauma in past 3 months, any history of ICH, major surgery in past 14 days, active bleeding in past 21 days, MI in past 3 months, seizure at onset of stroke platelets <100,000, serum glucose <50, INR >1.7 if on warfarin, persistent blood pressure elevation
R brain bleed/infarct assessment
eyes deviate toward pathology (R), L sided muscle weakness/paralysis, L homonymous hemianopsia, L Babinski, emotional lability
What if Dilantin level is therapeutic and patient seizes?
give Lorazepan
signs of meningeal irritation
headache nuchal rigidity Brudzinsky sign Kernig's sign
S/S of epidural hematoma
headache, irritability, confusion, vomiting, ipsilateral pupil dilation, often BEFORE decreased LOC, contralateral hemiparesis/ hemiplegia, decreasing LOC ALWAYS ACUTE
temporal lobe function
hearing, sense of taste and smell, interpretations
S/S of AVM
hemorrhage (most common, usually small AVMs), seizures (2nd most common, usually large AVMs)
Cushing's triad is a sign of ____
herniation of the brain
complications of SAH
hydrocephalus may develop since the chorionic villi in the subarachnoid space reabsorbs CSF, (if chorionic villi are blocked, CSF may not be able to be reabsorbed, rebleed and vasospasm are manifested by change in LOC, vasospasm results in brain ischemia, may be a devastating complication
respiratory patterns are associated with brain-stem abnormalities: -midbrain problem = ____ -pontine problem = ____ -medulla problem = ____
hyperventilation apneustic breathing ataxic, ARREST
Cushing's triad S/S
increase SBP, widening pulse pressure, decrease heart rate, decreased respiratory rate
Pathophysiology of Status Epilepticus (Early)
increased cerebral blood flow, tachycardia, hypertension, increased PaCO2, decreased PaO2, increased glucose (stress response), increased K+ (destruction of skeletal muscle cells)
bacterial meningitis findings
increased protein and WBCs, decreased glucose, purulent CSF, opening pressure >180
viral meningitis findings
increased protein and WBCs, normal glucose, clear CSF, opening pressure is often normal
do not ___ with a basilar skull fx
insert a nasogastric tube, may displace up to brain, use orogastric tube
What is the worst complciation after tPA administration?
intracranial hemorrhage, watch for change in LOC
pupil changes are ____, ____ as the pathology
ipsilateral, same side as pathology
uncal herniation is a ___ shift, ____ initial change in LOC
lateral no initial change in LOC
Kernig's sign
legs up and out, pain in neck and leg
epidural hematomas are usually due to ____
meningeal artery bleed secondary to temporal bone trauma with bleeding between skull and dura rapid developing symptoms
basilar fx is linear fx that occurs in the floor of the cranial vault (skull base), results in ____
meningeal tear
Duchenne Muscular Dystrophy (DMD)
most common form of MD onset very young wheelcahir bound by 12 years of age most patients die in their late teens or twenties as a result of respiratory infections or cardiomyopathy
myasthenia gravis vs cholinergic crisi
myasthenia gravis: due to underdiagnosed/ under treatment or acute exacerbation, deficiency of acetylcholine cholinergic crisis: due to overtreatment, excess of acetylcholine
encephalopathy definition
nonspecific term for any diffuse disease of the brain that alters brain function or structure
parietal lobe function
obejct recognition by size, weight shape, body part awareness
Inclusion criteria for tPA
onset < 4.5 hours CT negative no contraindications
Becker muscular dystrophy (BMD)
onset is usually later and symptoms are usually midler than DMD children can usually walk until they are approx 15, with some people continuing to walk as adults usually survive into their mid-40's the most common cause of death is heart failure from cardiomyopathy
tensilon test
patient is given tensilon 2mg IV in myasthenic crisis: clinical improvement is seen in cholinergic crisis: increased muscle weakenss and sludge is seen (salivation, lacrimation, urination, defecation, GI distress, emesis)
How is a myasthenia crisis differentiated between a cholinergic crisis?
patient is given the "tensilon test"
frontal lobe function
personality, abstract thought, long-term memory
treatment of GBS
plasmapheresis exchange (complete exchange os plasma with the removal of abnormal circulating antibodies that affect the myelin sheaths; removal of these antibodies will lessen the severity and duration of GBS), mechanical ventilation for respiratory failure, corticosteroids, IVIG
Babinski reflex
positive is abnormal in adults (toes flair up toward the head when the bottom of the foot is stroked), due to pressure on pyramidal/motor tracts in cerebrum, found on opposite side of damage
Doll's eye assessment
positive: eyes move in the opposite direction of head turn, positive reflex is good ("It's good to be a doll")
Hunt & Hess grading system for SAH on presentation with SAH helps ____
predict outcome and immediate treatment
clinical presentation of myasthenia gravis
progressive skeletal muscle weakness, early: easily fatigued, later: paralysis, 70% have ocular dysfunction (ptosis, diplopia, difficulty keeping eye closed)
S/S of basilar skull fracture
raccoon eyes, Battle's sign (discoloration at back of ear), otorrhea (fluid from ear due to meningeal tear), rhinorrhea (due to meningeal tear, CSF from nose, no nose blowing), lose crnail nerve 1, no sense of smell
Status epilepticus definition
seizure activity of 5 minutes or more caused by a single seizure or series of seizures with no return of consciousness between seizures
central herniation results in ____ and then ____
slight change in LOC and then coma
Broca's area
speech/language in L hemisphere
when to terminate apnea test early
spontaneous respiratory movements noted, SBP<90, SpO2 falls below 85%, unstable cardiac arrhythmias occur
H&H Scored IV
stuporous, moderate or severe hemiparesis, perhaps mild posturing
Why should you not treat BP unless SBP is >.220 or DBP is >120 in an event of an acute ischemic stroke?
sudden decrease in blood pressure will decrease perfusion to an area of the brain that has lost perfusion, may increase size of ischemic area
classic triad of symptoms of aneurysm rupture
sudden explosive HA, decreased LOC, nuchal rigidity, + Kernig's sign
Apnea test positive interpretation
supports brain death, absent respiratory movements, PaCO2 >60 or PaCO2 20 mmHg over baseline
central herniation definition
swelling on both side, downward displacement of hemispheres
brain herniation occurs when ____
swelling within the brain becomes so severe that structures of the brain are squeezed to the point where blood cannot get up into the brain and death may occur
Goal BP for 1st 24 hours after tPA
systolic <180 and diastolic <105
Guillain-Barre Syndrome (GBS)
temporary paralysis caused by an autoimmune attack on peripheral myelin, causing weakness and usually ascending paralysis of the limbs, face and diaphragm, protein in CSF, no alteration in LOC
Apena test indeterminate
test terminated prior to achieving a PaCO2 >60 or 20mmHg above baseline, PaCO2 is less than 60 or <20 mmHg over baseline
all cranial nerves arise from ____ except cranial nervers ____ and ____ which arise from ____
the brain stem cranial nerves I and II above the brain stem
oculovestibular reflex assessment
the patient's eyes are held open while ice water is injected slowly into the ear canal and the eye response is observed (cold calorics) positive: eyes move toward the side of the ice water injection- positive is good)
Lower RAS is responsible for ____
the sleep-wake cycle
Why would 0.45NS or D5W be contraindicated for a patient with elevated ICP?
these are hypotonic fluids. They would rapidly leave the vascular compartment and go intracellular. In the brain, which already has an increase in ICP, cell "swelling" would exacerbate the problem
eyes deviate ____ the pathology
toward
what type of herniation results from an epidural hematoma?
uncal
types of brain herniation
uncal central
occipital lobe function
vision, visual recognition, reading comprehension
intracerebral hematoma definition
within the brain tissue