Cerebrovascular evaluation Flashcards
what is the first branch off of the ECA?
superior thyroid artery
your patient complains of increasing episodes of unilateral facial and arm weakness rather than leg problems and behavioral changes. which vessel do you most likely suspect has an obstruction? a. anterior cerebral artery b. middle cerebral artery c.basilar artery d. posterior cerebral artery
b. middle cerebral artery pg 219 table
a patient has contralateral weakness, paralysis, numbness and sensory changes; ipsilateral amaurosis fugax and or a bruit. where would you expect the obstruction to be?
internal carotid
a patient has aphasia or dysphasia; severe contralateral hemiparesis or hemiplegia ( more severe in the face and arm rather than leg ) where would you expect the obstruction to be?
middle cerebral artery
a patient contralateral hemiparesis ( in leg) incontinence, loss of coordination, impaired motor and sensory function. where would you expect the obstruction to be?
anterior cerebral artery
a patient numbness around lips and mouth diplopia, poor coordination, dysphagia, vertigo, amnesia and ataxia. where would you expect the obstruction to be?
vertebrobasilar
a patient has dyslexia, coma ( paralysis usually absent) where is the obstruction
posterior cerebral artery
symptoms usually last from a few minutes to a few hours but never more than 24 hours. what is this called
TIA Transient ischemic attack
what is the etiology of a TIA ? and where is the most common source?
embolic, heart or carotid artery
What does RIND stand for? and how long does it last? what does it mean for the brain tissue?
reversible ischemic neurologic deficit. takes slightly longer than 24 hours to resolve, damage to the brain but it recovers completely
if a patient has bilateral blurred vision or paresthesia and complains of vertigo, ataxia and drop attacks what would you expect them to have?
VBI vertebrobasilar insufficiency
when there is permanent neurologic deficit what happened to the patient
CVA cerebrovascular accident
name the parts of the circle of willis (8)
anterior communicating artery, anterior cerebral arteries,middle cerebral, ICA,posterior comminicating, posterior cerebral , basilar, vertebrals
where do the vertebral arteries originate from? which one is bigger? what do they unite for form?
subclavian, left, basilar
the supraorbital artery arrises from the?
ophthalmic artery
the supraorbital artery joins the ECA via what?
branches of the superficial temporal artery
where does the frontal artery arise from?
ophalmic artery
the nasal artery which branches from the____ to supply the nose.. it joins the ECA via what?
frontal artery, facial artery
the ICA and ECA connection via what?
ophthalmic and orbital arteries, the meningohypophyseal branches and the carotcotypmanic brance
bernoulli principle stated what?
the higher the velocity the lower the pressure
poiseuille law defines what?
pressure and radius
what is the conservation of mass? formula
V=Q/A
when perminanent neurologif deficit happens what is the cause
Ceverbrovascular accident
the two most common mechanisms of cerebrovascular insufficiency are _____ and ____
ischemia and hemorrhage
what are the 3 leading causes of ischemia?
atherithombilic pathologies, cardiogenic pathologies, and lacunar infarctions
what is ischemia?
blood dificency due to stennosis or occlusion
what is the second most common cause of cerebrovascular insufficiency?
hemmorhage
what is the accumulation of lipids that is covered by more lipid material, collegen and elasric fiber?
fibrous plaque
what does this represent?
intraplaque hemorrhage
what is the most frequent source of a emboli?
the heart
a pulsatile mass in the supraclavicular area of the neck is most often associated with what?
tortuous vessel
____ ___is most commonly caused by dusplasia of the media along with overgrowth of collagen
Fibromuscular displasia
_______ is most commonly caused by trama that resulta in a sudden tean. however you can have a connective disorder that can cause this what is the syndrome?
dissection, Ehlers-danlos
what does lateralizing mean?
indicates which side or hemisphere of the brain has been affected
what does nonlateralizing symptom mean?
symptoms e.g. vertigo, ataxia usually are associated with problems of the brainstem or posterior circulation
What is Dysphasia
impared speech
what is aphasia
inability to speak
a lesion in the______ ______ _____ artery may cause dysphasia or aphasia
left middle cerebral artery
the right hemisphere is dominant in a _______handed person
left
what is amaurosis Fugax?
temporary partial or total blindness usually only one eye
what is homonymous hemianopia?
the loss of vision in one half of the visual field or both eyes may be evident after a stroke affecting the cerebral cortex
what is vertigo?
difficulty in maintaining equilibrium
what is ataxia?
muscular incoordination
what is diplopia?
double vision
infarction of the ____________ artery is the most commin cause of stroke
middle cerebral artery
T/F
a previously documented bruit that is no longer evident may indicate a lesion that has progressed from <90% diameter reduction to >90% diameter reduction
true
for a carotid exam if the PSV is < 125 what does this indicate?
Normal PSV
when peforming a carotid ultrasound and the PSV is >12 and EDVis <140 what does this suggest?
50%- 79% stenosis
When peforming a carotid ultrasound and the PSV> 125 and EDV>140 what does this suggest?
80-99% stenosis
When the PSV and EDV are completely absent during a carotid ultrasound what does this suggest?
occluded vessel
______________ reflectsflow turbulence and consistent with flow turbulance and significant flow alterations
sprectral broadening
The loss of diastolic component in the ipslateral common carotid artery usually is consistent with an offlision of?
ICA
T/F
Poor cardiac output of stroke volume may result in bilaterally diminished flow velocities systemically
True
What does diminished velocities unilaterally suggest when doing a carotid exam?
proximal disease e.g innominate or common artery occlusive disease
Antegrade flow in systole with sustained reversal of flow during diastole may indicate what?
aortic regurgitation or insufficiency
What does this represent?
fibromuscular displasia (FMD)
if you were to see a high resistance rather than the expected low resistance flow in the ICA what would you expect to find?
distal obstruction e.g. blockage at the carotid siphon
low velocities and increased acceleration time, resulting in a more rounded waveform of the CCA are consistent with what? if this was seen bilaterally what would you expect? unilateral what would you expect?
proximal disease. poor cardiac output, proximal disease
if a patient has >230 ICA PSV and a ICA/CCA Ratio of >4.0 what would you expect the diameter reduction to be?
>=70%DR
in general, stented vessels have ________ velocities
elevated
the angle of insonation for transcranial doppler is assumed to be ?
0 degrees
What can you see with the Transtemporal approach?
MCA, Terminal ICA, ACA/MCA bifurcation,ACA and PCA
What can you view with the Transorbital approach?
Ophthalmic and Distal ICA at the carotid Siphon
What can you view with the transforamenal apporach?
VA and BA ( basilar arteries)
When is the Anterior communicating artery usually seen?
only when actively involved in collateral flow
T/F Low flow velovities and poor angle of insonation make the posterior communicating arteries difficult to identify unless they are acting as a collateral
True
What are the 3 segments of the Siphon aka cavernous carotid?
parasellar, Genu and supraclinoid
using the Transtemporal window what way should flow direction be for the MCA?
towards, antegrade
using the transtemporal window what way should the terminal ICA be flowing be flowing towards the transducer?
bidirectional
using the transtemporal window what way should the ACA/MCA bifurcation be flowing towards the transducer?
towards and away, bidirectional
using the transtemporal window what way should the ACA be flowing towards the transducer?
away, retrograde
using the transtemporal window what way should the PCA be flowing towards the transducer?
towards antegrade
using the transorbital window what way should the ophthalmic artery be flowing towards the transducer?
towards antegrade
using the transorbital window what way should the Distal ICA at the carotis siphon be flowing towards the transducer? all three segments
Supraclinoid: away retro
Genu: simultaneously towards and away bidirectional
Parasellar: towards ante
using the transforamenal window what way should the VA be flowing towards the transducer?
away, retrograde
using the transforamenal window what way should the BA be flowing towards the transducer?
away retrograde
__________ refers to the reversal of flow direction in the anterior cerebral artery ipsilateral to a proximal internal carotid stenosis or occlusion
Crossover collateralization. the flow is crossing over from the contralateral internal carotid artery
_____________is evident when flow reversal ( awawy from the transducer rather than towards) in the ophthalmic artery ipsilateral to the proximal stenosis. What is this attrubited to?
External to internal collateralization. this abnomality can be attributed to flow from the external carotid artery branch that anastomose with the terminal branch of the ophthalmic artery
with External to internal collateralization how can you confirm this type collateral? what will it show
compressing the external carotid branches such as the superficial temporal and facial arteries. there will be a reduction , obliteration or flow reversal
__________ occurs when blood is shunted from the vertebrobasilar arteries through the ipsilateral posterior cerebral and posterior communicating arteries to supply the anterior circulation.
posterior-to anterior collateralization
______ is a complication of subarachnoid hemorrhage related to rupture of an intracranial aneurysm, AV nalformatior, hypertension or head trama. It is a functional, transient narrowing of the intracranial arteries usually occuring and resolving within two weeks following the initial bleed
Vasospasm
____________ aka ________ is a index used to differentiate between high velocities that are significant for vasospasm and hyperdynamic flow secondary to low hematocrit, volume expansion and increased blood pressure
Hemispheric ratio aka lindegaard ratio
what is the degree of vasospasm in the MCA and ICA. what is normal?
<120
what is the degree of vasospasm in the MCA and ICA. what is severe?
>= 200 ratio is >= 6
patients with ______________ disease can develop intracranial narrowing/ stenosis.
sickle cell
in a sickle cell patient..TAMVs in the MCA are considered to be wnl when they are ?
<= 170cm/sec
in a Sickle cell patient TAMVS ____ cm/sec suggest the need for chronic blood transfusion to reduce hemoglobin S.
>= 200 cm/sec
Death of brain tissue, intracranial bleeding and swelling can increase intracranial pressure when intracranial pressure exceeds systoluc arterial pressure what happens?
perfusion stops
when blood is bring shunted away from the brain secondary to a stenosis or occlusion in the ipsilateral artery what is this an example of?
subclavian steal
____________ is a disease involving inflammation in the walls of the largest arteries in the body of the AO and its main branches. this is aka as the pulseless disease why?
Takayasu’s arteritis,
Weak pluse or loss of pulses in the arms or legs
Takayasu’s arteritis occurs more commonly in? sex and age
women/ young women/ teenage girls
_______ is the inflammation of the distal segment of the superficial temporal atery or its frontal and parietal branches. patients experience headaches, tenderness on palpation and possibly ipsilateral visual changes including blindness
temporal arteritis
When you see this being documented in the CCA what do you expect the patient to have?
left ventricular assist device. continuous flow pumps are used which will result in nonpulsatile flow
you are requested to do a carotid duplex scan, you have not had the chance to go through the medical record. what is the conclusion you would most likely come to based on the image?
intra- aortic baloon pump wnl
when peforming a Carotid exam and you have not looked at the patients chart what would you expect the patient to have with this type of flow pattern?
biventricular assist device
When peforming a arteriograph, following the removal of the catheter pressure is applied to the puncture site and the patient is positioned supine for how long?
2-6 hours
What is the percent of stenosis calculation aka diameter reduction?
[1-(d/D)] x100
subract from 1 the diameter of the residual lumen(d) divided by the diameter of the true lumen (D) then multiply by 100
What is the calculation for percentage stenosis - AREA reduction?
[1-(d^2/D^2)]x100
retrograde flow in a cerebral vessel indicated what?
collateral
which of the following is not a branch of the external carotid artery?
a. facial
b. maxillary
c. opthalmic
d. occipital
c opthalmic ICA
what does the ophthalmic artery branch into 3?
frontal, nasal artery, supraorbital
off of the ECA which of the 8 arteries connect to the ICA branches for collaterials
occipital, facial and superfcial temporal artery
in the inrtacranial circulation what is the most important collateral pathway with a occluded ICA?
anterior communcating artery
what becomes an extra to intracranial collateral route in the prescense of significant ICA disease?
supraorbital and ophthalmic arteries via ECA branches
what is the rapid growth of intima following carotid endarterectomy?
neointimal hyperplasia
using the transtemporal window, the normal flow in the ipsilateral posterior communicating artery is?
a. away
b. towards
c. not visualized
d. dependent on direction of VA
not visualized with temporal apprach but the PCA is not the communicating artery
