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