CVD Flashcards
For embolic strokes, the most
important risk factors are structural cardiac disease and
arrhythmias, mostly atrial fibrillation, which increases
the incidence of stroke about _____, and by 18-fold if, as
was common in the past, there is also ______
6-fold
rheumatic valvular
disease
____ hastens the atherosclerotic process in both
large and small arteries
Diabetes
As in the case of coronary artery disease, the level
of ________cholesterol has the most
impact on the incidence of stroke but elevated triglycerides may also confer risk.
low-density lipoprotein (LDL)
Subsidiary factors, such as low
______________,
are associated with an increased stroke rate in several
studies, including one in which we participated, but the
mechanism of this effect is obscure
potassium intake and reduced serum levels of potassium
Chromosomal abn associated with stroke and has putative connections with vascular dse
Chromosome 12
Atheromatous plaques preferentially form at branching
points and curves of the cerebral arteries.
The most frequent sites are
(1) in the ________at its origin from the common carotid; (2) in the ___________ and at their junction to form the basilar artery;
(3) in the stem or at the main bifurcation of the ______
(4) in the ____________ as they wind around the midbrain; and
(5) in the proximal anterior cerebral arteries as they pass anteriorly and curve over the corpus callosum
internal carotid arteries
cervical part of the vertebral arteries
middle cerebral arteries;
proximal posterior cerebral arteries
an atherothrombotic lesion in a proximal vessel may
serve as the nidus for the formation of an embolus that
manifests itself as a stroke in one of the territories of that
vessel-called__________ embolism
“artery-to-artery”
it is the high degree of stenosis, usually above ______ percent of the original lumen compromised, or a residual lumen of less than approximately ______mm, of the carotid artery that
is most likely to be associated with strokes in the distal
territory of the vessel.
90
2
________infarction nearly always
indicates embolism (although venous occlusion can do
the same)
hemorrhagic
In CE stroke, Any region of the brain may be affected, the
territories of the middle cerebral artery, particularly the
________ division, being most frequently involved
superior
According to the Framingham Heart Study, patients
with chronic atrial fibrillation are approximately_______ times more liable to stroke than an age-matched population with normal cardiac rhythm
six
the risk for stroke conferred by the presence
of atrial fibrillation varies with age, being 1 percent per
year in persons younger than age 65 years, and as high
as_______ percent per year in those older than age 75 years
with additional risk factors
8
Cardiac catheterization or surgery,
especially _________, may disseminate fragments
from a thrombus or a calcified valve
valvuloplasty
as many as 38 percent of a group of
patients with no discernible cause for embolic stroke had
echogenic atherosclerotic plaques in the ____________________ a size found to be
associated on a statistical basis with strokes.
aortic arch that
were greater than 4 mm in thickness,
This ___________ syndrome is most evident in cases of posterior cerebral artery occlusion, either from a cardiagenic source or from a thrombus in the proximal vertebral artery
migrating or traveling embolus
_______ occurs when an abnormal communication
exists between the right and left sides of
the heart (particularly a patent foramen ovale [PFO])
or the alternative route of connection via a pulmonary
arteriovenous fistula
Paradoxical embolism
_______ (often from previous pulmonary embolism) favors the occurrence of paradoxic embolism, but these strokes occur even in the absence of pulmonary
hypertension.
Pulmonary hypertension
the risk of second stroke was 2 percent in those with
a PFO alone and 15 percent among those with both a
PFO and an _________
atrial septal aneurysm
T or F
about one-third of patients in all age
groups will be found to have a PFO, and anticoagulation
or repair of these lesions in older patients with embolic
stroke has not been shown to be beneficial
T
Usually, when valvular prolapse is associated
with stroke, it is usually ___________and a propensity to accumulate clot behind the
valve.
severe with ballooning of the
valve
The ________ are a potential, if infrequent, source
of cerebral emboli, as reflected by the occurrence of cerebral abscesses in association with pulmonary infectious
disease
pulmonary veins
In _________, pulmonary shunts serve as a conduit for
emboli
Osler-Weber Rendu disease
A rare type of embolism follows thyroidectomy,
where thrombosis in the stump of the ___________ extends proximally until a section of the clot, protruding into the lumen of the carotid artery; is carried into the cerebral circulation
superior thyroid
artery
tumor embolism with stroke is known from_______ and _______, and occasionally with other tumors, even systemic ones
cardiac myxoma and fibroelastoma
______________
is a rare complication of abortion, scuba diving, or
cranial, cervical, or thoracic operations involving large
venous structures or venous catheter insertion;
Cerebral air embolism
brief, reversible episodes of focal ischemic brain disturbance without evidence of cerebral infarction
TIA
Approximately _________percent of infarcts that
follow TIAs occur within a month after the first attack,
and approximately 50 percent within a year
20
the occurrence of
carotid TIAs is a predictor not only of cerebral infarction
but also of ________
myocardial infarction.
visual episodes evolve
swiftly; over 5 to 30 s, and are described as a horizontal
shade falling (or rising) smoothly over the visual field
until the eye is completely but painlessly blind.
transient monocular
blindness (also called amaurosis fugax or TMB)
escalating episodes
of weakness in the face, arm, and leg and culminating
in a capsular lacunar stroke.
“capsular warning syndrome
Embolization of _______ from atherosclerotic sites indeed may be the cause of attacks in some cases, but it is difficult to understand how attacks of identical pattern could
be caused by successive emboli from a distance that
enter the same arterial branch each time.
fibrin-platelet material
Restated, a single transitory episode, especially
if it lasts longer than 1 h, and m ultiple episodes of diff erent pattern, suggest ___________ and must be distinguished from brief (2- to 1 0-min) recurrent attacks of the same clinical pattern, which s uggest TIAs from ________
embolism
atherosclerosis and thrombosis in a large vessel.
exercise and postural TIAs, when they do occur, are particularly suggestive of stenosis of
aortic branches, as occurs in _______
Takayasu disease
hemodynamic changes in the retinal or cerebral circulation make their appearance when the lumen of the internal carotid artery is reduced to \_\_\_\_\_\_\_\_\_\_ mm or less (normal diameter, 7.0 mm; range, 5 to 10 mm, lower part of this range in women).
2.0
___________have been recorded
in 10 to 15 percent of patients with vertebrobasilar
insufficiency
drop attacks
Cerebral infarction basically comprises two pathophysiologic processes:
one, a loss of the supply of _____________, and the
other, an array of changes in cellular metabolism consequent to the collapse of energy-producing processes, ultimately with disintegration of cell structures and their membranes, a process subsumed under the term _______
oxygen
and glucose secondary to vascular occlusion
necrosis.
Implicit in discussions of ischemic stroke and its treatment
is the existence of a ________zone that is marginally
perfused and contains at-risk but viable neurons
“penumbra”
Over a range of mean
blood pressures of approximately _________, the
small pial vessels are able to dilate and to constrict in
order to maintain cerebral blood flow (CBF) in a relatively
narrow range.
50 to 150 mm Hg
critical level for infarction for CBF
critical level was 23 mL/ 100 g/ min (normal is 55);
Reduction of CBF below 10 to 12 mL / 100 g/min causes infarction, almost regardless of its duration.
In the region of marginal perfusion, the _______ level increases (as a result of efflux from injured depolarized cells) and _________ and ________ are depleted
K
adenosine triphosphate (ATP) and creatine phosphate
A CBF of 6 to 8 mL/ 100 g/min causes marked
1.
2.
3.
invariably leading to histologic signs of necrosis
ATP depletion, increase in extracellular K, increase in intracellular Ca, and cellular acidosis,
After _______min of anoxia,
there was irreversible damage, reflected by an inability
of the tissue to utilize glucose and to synthesize protein
30
A reduction of even ________ (3.6 to 5.4°F) reduces the metabolic requirements of neurons and increases their tolerance to hypoxia by 25 to 30 percent.
2 to 3°C
These neurotransmitters,
released by ischemic cells, excite neurons and produce
an intracellular influx of Na and Ca
Glutamate and aspartate
Involved in the process of thrombosis are changes in a
number of natural anticoagulant factors such as
1.
2.
3.
4.
heparin cofactor 2, antithrombin III, protein C, and protein S.
________ is a vitamin K-dependent
protease that, in combination with its cofactors protein S
and antithrombin III, inhibits coagulation
Protein C
_______depicts the “time of flight” of blood through vessels
and is not as accurate as CT angiography in measuring
the degree and morphology of changes within a
cerebral or intracranial vessel
MRA
___________which demonstrate atheromatous plaques and stenoses of large vessels, particularly of the carotid but also of the vertebrobasilar arteries
CDS
a bruit at the angle of the jaw is caused by stenosis at
the origin of the____________ or is a radiated
murmur from the aortic valve and can then be misleading
external carotid artery
the right CCA arises at the level of the sternoclavicular notch from the____________ and the left common carotid comes directly from the __________
innominate (brachiocephalic) artery,
aortic arch
The common
carotid arteries ascend in the neck to the ______ level,
just below the angle of the jaw, where each divides into
external and internal branches (sometimes the bifurcation
is slightly above or below this point).
C4
Occlusion of the ______________-for example by an
embolus to its distal part-produces a clinical picture
like that of middle cerebral artery occlusion
distal intracranial portion of the
internal carotid artery (the “T”)
Headache, located as a rule above the _____, on
the side of the infarction, may occur with thrombosis
or embolism of the carotid artery, but cranial pain is not
invariable and is usually mild
eyebrow
The headache associated with occlusion of the middle cerebral artery tends to be more ______, at the temple; that of posterior cerebral occlusion is located in or ______
lateral
behind the eye
The MCA may b e occluded i n its longitudinal portion,
or the stem, that is proximal to its bifurcation (the term_________
Ml
Occlusion of the stem of the MCA is usually caused
by embolus and less often by a ______
thrombus superimposed
on an atherosclerotic plaque
An embolus entering the middle cerebral artery most often lodges in one of its two main branches, the_____________ (supplying the rolandic
and prerolandic areas) or the ___________ (supplying
the lateral temporal and inferior parietal lobes
superior division
inferior division
In approximately ______percent of individuals, both posterior cerebral arteries are formed by the bifurcation of the basilar artery and thin posterior communicating arteries join this system to the internal carotid arteries
70
In 20 to 25 percent, one posterior cerebral artery arises from the basilar in the usual way, but the other arises from the internal carotid, a ___________
persistent fetal pattern of circulation
The _______________, which arise just above the basilar bifurcation supply the red nuclei, the substantia nigra bilaterally, medial parts of the cerebral peduncles, oculomotor and trochlear nuclei and nerves, reticular substance of the upper brainstem, decussation of the superior cerebellar peduncles, medial longitudinal fasciculi, and medial
lemnisci.
interpeduncular
branches of the PCA
The ___________ (also called paramedian
thalamic arteries) arise slightly more distally from the
stem, nearer the junction of the posterior cerebral and
posterior communicating arteries (P2 segment of the
artery) and supply the inferior, medial, and anterior parts
of the thalamus
thalamoperforate branches
The______________ branches arise still
more distally, opposite the lateral geniculate body, and
supply the geniculate body and the central and posterior
parts of the thalamus
thalamogeniculate
___________follows infarction of the sensory relay nuclei in the thalamus, the result of occlusion of thalamogeniculate branches
The thalamic syndrome of Dejerine and Roussy
Central _______ and _____ are a
result of occlusion of the interpeduncular branches of the
posterior cerebral artery
midbrain and subthalamic syndromes
Syndromes of the paramedian arteries, including the proximal posterior cerebral artery, have as their main feature a:
third-nerve palsy combined with contralateral hemiplegia_________
contralateral ataxic tremor ( ___________),
or homolateral ataxia, hemiplegia with contralateral
third-nerve palsy (_________)
( Weber syndrome),
Claude syndrome
Benedikt syndrome
Here the most
common effect is an extrapyramidal movement disorder
Anteromedial-inferior thalamic syndromes
Occlusion of the paramedian thalamic branches
to the mediodorsal nucleus is a recognized cause of an
amnesic ________
(Korsakoff) syndrome
Occipital infarcts of the dominant
hemisphere may cause alexia without agraphia, anomia
________, a variety of visual agnosias, and rarely
some degree of impaired memory.
(amnesic aphasia)
Sometimes
the patient is unaware of being blind and denies the problem
even when it is pointed out to him _________
(Anton syndrome).
With more anteriorly placed lesions of the occipital pole,
there may be homonymous paracentral scotomas, or the
occipital poles may be spared, leaving the patient with
only_________
central vision
With bilateral lesions that involve the inferomedial
portions of the temporal lobes, including the hippocampi
and their associated structures, the impairment of memory may be severe, causing the _________
Korsakoff amnesic state
In several of our patients, a solely left-sided infarction
of the inferomedial temporal lobe impaired____
retentive
memory
Dissection of the vertebral artery by contrast is well
described; it declares itself by ________ pain and
deficits of brainstem function
cervicooccipital
Examples of posterior circulation stroke in children have
been reported in association with __________
and other atlantoaxial dislocations, causing the vertebral
arteries to be stretched or kinked in their course through
the transverse processes of C1-C2
odontoid hypoplasia
If the subclavian artery is
blocked proximal to the origin of the left vertebral artery,
exercise of the arm on that side may draw blood from the
right vertebral and basilar arteries, retrograde down the
left vertebral and into the distal left subclavian arterysometimes
resulting in the symptoms of basilar insufficiency.
This is called _______
subclavian steal
occlusion of the vertebral artery or one of
its medial branches produces an infarct that involves the
medullary pyramid, the medial lemniscus, and the emergent hypoglossal fibers; the resultant syndrome consists of a contralateral paralysis of arm and leg (with sparing of the face), contralateral loss of position and vibration sense, and ipsilateral paralysis and later atrophy of the tongue. This is the _________
medial medullary syndrome
Tissue plasminogen activators (recombinant tPA) convert
________
plasminogen to plasmin
The benchmark study organized by t_____________has provided evidence
of benefit later from intravenous tPA
the National
Institute of Neurological and Communicative Disorders
and Stroke (see the NINCDS and Stroke rtPA Stroke
Study Group in the references)
Findings of the NINCDS trial
Treatment within 3 h of
the onset of symptoms led to a 30 percent increase in
the number of patients who remained with little or no
neurologic deficit when reexamined 3 months after the
stroke
In rtPa Tx, The relative improvement in neurologic state came at the expense of a ______ risk of symptomatic cerebral hemorrhage
6 percent
This refers to the opening of the carotid artery or an
area of intracranial atherosclerosis immediately after a
stroke with the intention of improving the clinical outcome
Acute S u rg i ca l Revasc u l a rizati o n
For pts for revascularization, If the interval is longer
than ______ h, opening the occluded vessel is usually of
little value and may present additional dangers
12
The two situations in which the immediate
administration of heparin or an equivalent agent such as
enoxaparin have drawn the most support from clinical
practice are in ___________and in impending_______
basilar artery thrombosis with fluctuating deficits
carotid artery occlusion from
thrombosis or dissection.
Percentage protection from recurrent stroke for patients given Heparin
2%
How to give Heparin in acute stroke
In the event heparin is used, and assuming tPA has
not been used in the preceding 24 h, heparin may be
given intravenously, beginning with a bolus of 100 U / kg
followed by a continuous drip (1,000 U /h) and adjusted
according to the partial thromboplastin time (PTT).
In Heparin infusion for acute stroke,
When the PTT exceeds _______, it is preferable to discontinue the infusion, check the blood clotting values, and then reinstitute the infusion at a lower rate based on the test results
100 s
In Warfarin anti-coagulation,
65 years of age in these trials did not clearly benefit from
long-term prophylactic anticoagulation unless there were
additional cerebrovascular risk factors such as _________________
diabetes, hypertension, congestive heart failure, or cardiac valvular disease.
Drugs that may alter anti-coagulant effects
aspirin, cholestyramine, alcohol, carbamazepine, cephalosporin and quinolone antibiotics, sulfa drugs, and high-dosage penicillin
In patients on Warfarin,
This is the result of a paradoxical microthrombosis of skin vessels and is liable to occur in patients with unsuspected deficiencies of endogenous clotting proteins (S and C).
Hemorrhagic skin necrosis
Reason of transient hypercoagulability after starting warfarin
upregulation of protein S);
there
is no reason to favor warfarin in comparison to aspirin in
cases of atherothrombotic stroke.
What trial
Warfarin-Aspirin Recurrent Stroke Study (WARSS;
Warfarin-Aspirin InSymptomatic Intracranial Disease (WASID
In pts on Warfarin, An INR above 5 in a patient who must remain anticoagulated-for example, one with a prosthetic heart valve-may be corrected with small doses of vitamin K____________preferably given intravenously
(0.5 to 2 mg),
modest reduction in mortality and stroke
recurrence if aspirin was given within 48 h of stroke.
What trials?
IST, CAST
MOA of ASA
combines with the
platelet membrane and inhibits platelet cyclooxygenase,
thus preventing the production of thromboxane A2, a
vasoconstricting prostaglandin, and also prostacyclin a vasodilating prostaglandin
______ and ________ are considered, on the basis
of clinical trials, to be equivalent to or marginally more
effective than aspirin for the prevention of stroke but
they are more expensive
Ticlopidine and clopidogrel
ticlopidine may produce _______
and clopidogrel may cause _______
neutropenia
thrombotic thrombocytopenic purpura
______ in high doses has not been as
well tolerated by many of our patients because of dizziness induced by peripheral vasodilatation.
Dipyridamole
reduction in stroke recurrence during the first 90 days
after the first minor stroke or TIA by adding clopidogrel
to aspirin, either 75 mg or 300 mg, and no increase in
cerebral hemorrhages.
What trial?
CHANCE
In hemodilution for acute stroke, high incidence of short-term improvement when the hematocrit was reduced to approximately _____ percent
33
________ of the types administered
for cardiac disease have also been found to increase CBF
and to reduce lactic acidosis in stroke patients
Calcium channel blockers
For pts with PFO and stroke,
the rate of recurrent stroke was close to_______ percent per year in both the groups who had a procedure to close the defect and those who were treated with either warfarin or aspirin
1 to 2
Clinical indicators of worsening in acute stroke
worsening-drowsiness, a fixed (but not
necessarily enlarged) pupil, a Babinski sign on the side
of the infarction (on the preserved side of the body), and
changes in breathing pattern, as well as characteristic
imaging signs
The conclusion reached in each of these studies was that carotid endarterectomy for symptomatic lesions causing degrees of stenosis greater than 70 to 80 percent in diameter reduces the incidence of ipsilateral hemispheral strokes and shows greater benefit with increasing degrees of stenosis
North American
Symptomatic Carotid Endarterectomy Trial (NASCET)
and the European Carotid Surgery Trial (ECST).
In those with bilateral carotid disease, the risk of stroke after 2 years was ______, and if operated, _____
69 percent
22 percent.
best timing for CEA
maximum benefit
is accrued if surgery is performed within 2 weeks of
a TIA or minor stroke
In pts with carotid artery stenosis,
______ offers an alternative for the patient who is too ill
to undergo surgery
Stenting
Endarterectomy, in a small number of cases may
be followed by a new hemiplegia or aphasia that becomes evident in the hours after the procedure, usually by the time the patient arrives in the recovery room.
What type of complication?
intimal flap at the distal end of the endarterectomy and varying amounts of fresh clot proximal to it are usually encountered; but after removal and repair of the vessel, the effects of the stroke, if one has occurred, are not usually improved
The postoperative care of carotid endarterectomy
focuses on_________ that is
induced by exposing the carotid wall to high perfusion
pressure.
reversing reflex hypotension
An uncommon but rather striking _________ develops several days to a week after carotid endarterectomy.
The features are headache, focal deficits, seizures,
brain edema, or cerebral hemorrhage. These are thought
to reflect autoregulatory failure of the cerebral vasculature
in the face of abrupt restoration of normal blood pressure
and perfusion
hyperperfusion syndrome
A bruit generally corresponds to the
reduction in luminal diameter of the artery to _______or
less and, while found in a large proportion of patients
with severe stenosis, it is not specific and is heard in up to 10 percent of older patients who have little or no stenosis
2 mm
patients
with asymptomatic carotid bruits who were followed for 5
years were approximately ______ times more likely to have ischemic strokes than an age- and sex-matched population sample without carotid bruits.
three
ddx for self-audible bruit
carotid stenosis, dissection, or fibromuscular
dysplasia, but is usually of less consequence and in some
instances is associated with an enlarged and superiorly
located jugular bulb
asymptomatic carotid stenosis
of more than 70 percent carries a 2 percent annual risk of
stroke over a 5-year period and that the risk is reduced to
1 percent with endarterectomy.
What trial
(MRC
Asymptomatic Carotid Surgery Trial [ACST] Collaborative
Group),
T or F
endarterectomy does not reduce the incidence of strokes in patients who have asymptomatic carotid stenosis with
luminal narrowing that is less than 60 to 70 percent of normal diameter
T
Our usual practice with asymptomatic cases has been to reevaluate the lumen of the internal carotid artery (using ultrasonography) at \_\_\_\_\_\_
6- to 12-month
intervals.
In the case of an asymptomatic
but progressive stenosis, statin agents, accompanied by
________________
where applicable, are a reasonable alternative approach.
smoking cessation, aspirin therapy, and glucose control
In extensive brainstem infarction associated with
deep coma caused by basilar artery occlusion, the early
mortality rate approaches _____
40 percent
In stroke pts,
If clinical recovery does not begin in ______weeks, the outlook is poor for both motor and language functions.
1 or 2
In stroke pts,
motor and language deficits remain after _______ months
will be permanent
5 to 6
In some patients with extensive
____________, the hemiplegia remains flaccid;
the arm dangles and the slack leg must be braced to stand
temporoparietal lesions
Many patients complain of fatigability and are
depressed, possibly more so after strokes that involve the ______
left frontal lobe
When multiple infarcts occur over a period of months
or years, special types of dementia and gait failure may
develop. This disorder is called?
This disorder, referred to as arteriosclerosis dementia
and Binswanger subcortical leukoencephalopathy, probably represents the accumulation of multiple white matter infarcts and lacunes
________ on the other hand, refers
to continued TIAs or strokes while on low doses of the
medication.
“Aspirin failure”
______trial, has shown that secondary stroke prevention
is possible in patients with TIA or stroke in the prior
6 months with the use of high-dose atorvastatin (80 mg)
but the magnitude of benefit was small (approximately
3 percent)
Stroke
Prevention by Aggressive Reduction in Cholesterol Levels
(SPARCL) trial,
