The risk of myocardial infarction or other cardiac disorders in this patient is equal to or greater than the risk of recurrent stroke 5 years poststroke.. The slow, insidious progression
Trang 1Neurocysticercosis occurs when humans replace pigs in the life cycle and become intermediate hosts, typically by ingesting food or water contaminated by fecal matter
Stroke Prevention Aug 2005
TYPE A QUESTIONS (ONE BEST ANSWER)
1 A 72-year-old woman with hypertension and hyperlipidemia suddenly developed left homonymous hemianopia yesterday morning, and it has persisted She has no history of prior neurological symptoms Magnetic resonance imaging (MRI)/magnetic resonance angiography (MRA) shows a subacute right occipital stroke and diffuse large vessel atherosclerotic disease, with 60% stenosis of her left vertebral artery, 70% stenosis of her right vertebral artery, 90% stenosis of her left internal carotid artery (ICA), and 50% stenosis of her right ICA An echocardiogram shows no cardioembolic source Her annual risk of stroke related to the left ICA stenosis is approximately:
A 1% to 3%
B 5% to 7%
C 10% to 12%
D 15% to 17%
E 20% to 22%
Correct Answer: The correct answer is A This patient's left ICA stenosis is asymptomatic Her clinical symptoms are consistent with the MRI finding of a subacute right occipital stroke This implies a problem in the posterior circulation, and she has no history or MRI evidence of additional disease in the anterior circulation Natural history studies reflect an annual stroke risk of between 1% and 3% among persons with an asymptomatic 50% to 99% stenosis of a carotid artery
2 A 69-year-old man presents to the emergency department with the abrupt onset of right hemiparesis and expressive aphasia 1 hour ago His past medical history is remarkable for hypertension, type 2 diabetes mellitus, hypercholesterolemia, and smoking His examination reveals blood pressure of 180/90 mm Hg, heart rate 85/min and regular, temperature 37°C He has mild expressive language difficulty and 4/5 weakness in the right arm and leg with drooping of the right lower face His deficits improve over the next 30 minutes A computed tomographic (CT) scan of the head without contrast is negative Carotid ultrasound reveals 50% ICA stenosis bilaterally An electrocardiogram (ECG) reveals normal sinus rhythm, and a transesophageal echocardiogram reveals a small patent foramen ovale His fasting glucose is 130 mg/dL, and his low-density lipoprotein (LDL) cholesterol is 180 Which of the following is the most important modifiable risk factor in this patient for future risk of stroke?
A Hypercholesterolemia
B Hypertension
C Patent foramen ovale
D Diabetes mellitus
E Smoking
Correct Answer: The correct answer is B Hypertension is the most important modifiable stroke risk factor, accounting for 40% of stroke, depending on age group A direct and continuous relationship exists with the degree
of blood pressure elevation The other risk factors listed may contribute to his future risk of stroke but are not as important as the hypertension Obviously, the diabetic control, hypercholesterolemia, and smoking should be addressed as well The role of a patent foramen ovale in future risk of stroke in this patient is indeterminate The degree of carotid stenosis is not sufficient for him to clearly benefit from endarterectomy
3 A 74-year-old man with hypertension, diabetes, hyperlipidemia, and paroxysmal atrial fibrillation noticed a left visual field cut on awakening one morning Evaluation revealed an acute infarction in the territory of the right posterior cerebral artery He was started on warfarin at a dose of 5 mg a day Which of the following would be most appropriate to use while awaiting the target international normalized ratio (INR)?
A Aspirin
B Low molecular weight heparin, subcutaneous boluses
C Unfractionated heparin, intravenous (IV) boluses every 8 hours, titrated to partial thromboplastin time
D Unfractionated heparin, steady IV infusion, titrated to partial thromboplastin time
E Unfractionated heparin, subcutaneous boluses
Correct Answer: The correct answer is A Data do not support the use of unfractionated heparin or low molecular weight heparin until warfarin becomes therapeutic Aspirin may be started within 48 hours of stroke onset and discontinued when the INR reaches target
4 A 70-year-old man was hospitalized for an acute left middle cerebral artery-distribution ischemic stroke secondary to left ICA thrombosis and occlusion due to atheroma He is now recovering in the rehabilitation unit several weeks after the event He has a moderate mixed aphasia and right hemiparesis but is now ambulating with a cane and one-person assist He is on medications for hypertension and hyperlipidemia and takes aspirin 81 mg
Trang 2daily On admission, his ECG showed evidence of left ventricular hypertrophy (LVH) but no ischemia
Echocardiogram showed moderate LVH but no embolic source In discussing prognosis and possible additional
evaluation and therapy with the patient and his family, which of the following statements is most appropriate?
A The risk of myocardial infarction or other cardiac disorders in this patient is equal to or greater than the risk of
recurrent stroke 5 years poststroke
B This patient has likely experienced maximal neurological recovery from his stroke
C Noninvasive cardiac testing with a thallium stress test is not feasible in this patient with hemiparesis
D Left carotid endarterectomy would be helpful in preventing further stroke in this patient
E Coronary angiography is the most appropriate test to screen this patient for silent cardiac ischemia
Correct Answer: The correct answer is A Patients with ischemic stroke are at increased risk for cardiac disease
even if they lack symptoms of heart disease Over the next 2 to 3 years this patient's risk of recurrent stroke is
greater that his risk of myocardial infarction or cardiac death If he survives 5 years, his risk of symptomatic heart
disease is greater Screening for cardiac disease is reasonable in a patient with large vessel infarcts and could
include noninvasive tests, including stress echo and stress thallium These tests are feasible even in patients with
hemiparesis Coronary angiography should be reserved for patients with symptomatic heart disease and/or patients
with abnormal noninvasive testing Carotid endarterectomy is not appropriate for patients with carotid occlusion
Although much of the symptomatic improvement occurs within the first few weeks after ischemic stroke, additional
clinical improvement may occur many months later
5 Following a lacunar infarct of the left anterior thalamus, a 60-year-old man complains of difficulties with
short-term memory He is able to successfully manage a small business but states that he now has to keep a written list of
phone numbers of his business contacts Sometimes his wife has to remind him of the names of regular customers
He has been driving without difficulty and manages the accounts of his business His wife has been checking his
calculations and confirms that they are accurate He is able to manage activities of daily living at home without
difficulty The patient is acutely aware of his difficulties and is concerned that he may be getting Alzheimer's
disease On examination he scores 28/30 on the Mini-Mental State Examination with 2 points missed in recall The
remainder of his neurological examination is normal An MRI scan of the brain shows multiple white matter
lacunes as well as a small lacune in the left thalamus Which of the following disorders would best explain this
patient's cognitive disorder?
A Mixed vascular dementia
B Vascular dementia
C Alzheimer's disease
D Cognitive impairment/no dementia
E Generalized anxiety disorder
Correct Answer: The correct answer is D This patient has mild cognitive impairment confined to one domain
(memory) His impairment is not severe enough to significantly affect his functional abilities in employment or
other activities of daily functioning; therefore, he does not meet the criteria for dementia He is, however, at risk to
develop vascular dementia A lacune in the left anterior thalamus could certainly account for his memory
difficulties No other mentioned features suggest an anxiety disorder
6 A 60-year-old man presents for a general physical examination His past medical history is remarkable for type 2
diabetes mellitus, which has been well controlled on metformin He has no previous history of hyperlipidemia or
hypertension He has a 20-pack-year history of smoking but quit 15 years ago His family history reveals that his
mother died of heart disease at age 65 and his father died of stroke at age 70 His blood pressure is 160/90 mm Hg,
and the remainder of his physical examination is normal Which of the following statements is most accurate
concerning this patient's hypertension or its treatment?
A His risk of cardiovascular disease quadruples for every 20 mm Hg systolic increase in blood pressure
B The goal of blood pressure control in this patient should be a target of 140/90 mm Hg or less
C Use of an angiotensin-converting enzyme inhibitor may reduce this patient's stroke risk by mechanisms other
than blood pressure reduction
D Reducing this patient's blood pressure to 140/80 mm Hg would reduce his stroke risk by 10%
E Antihypertensive medications are not indicated in this patient and will not reduce stroke risk
Correct Answer: The correct answer is C Hypertension is a major risk factor for cardiovascular and
cerebrovascular disease The cardiovascular risk doubles for every 20 mm Hg systolic or 10 mm Hg diastolic
increase in blood pressure Blood pressure control should be less than 140/90 mm Hg or less than 130/80 mm Hg in
diabetic individuals or those with renal insufficiency Clinical trials of primary stroke prevention have shown 38%
fewer strokes with 10 mm Hg to 12 mm Hg systolic and 5 mm Hg to 6 mm Hg diastolic blood pressure reduction
Angiotensin-converting enzyme inhibitors reduce blood pressure but also may have other beneficial effects,
including inhibition of vasoconstriction, improved endothelial function, and enhanced fibrinolysis
Trang 37 The major advantage clopidogrel provides over ticlopidine involves which of the following:
A Cost
B Drug-drug interactions
C Efficacy
D Route of administration
E Side effect profile
Correct Answer: The correct answer is E Ticlopidine is associated with a risk of neutropenia and thrombocytopenia, requiring frequent laboratory monitoring, and also a risk of thrombotic thrombocytopenic purpura Neutropenia has not been a concern with clopidogrel, and although thrombocytopenic purpura may occur occasionally with clopidogrel, the relationship is still under study and remains uncertain Both ticlopidine and clopidogrel are administered orally Although no head-to-head trials have been conducted, comparisons of number needed to treat favor ticlopidine
8 Which of the following is not one of the markers currently used by the Joint Commission on Accreditation for Healthcare Organizations (JCAHO) for disease-specific certification of stroke care?
A Antithrombotics prescribed at discharge
B Lipid profile assessment
C Nutritional evaluation and counseling
D Rehabilitation consideration in appropriate patients
E Smoking cessation counseling
Correct Answer: The correct answer is C Nutritional intervention is not one of the 10 JCAHO markers for certification of stroke care All the other factors listed are
9 A 76-year-old man suddenly developed numbness and weakness on the left side of his body, and evaluation revealed a stroke in the distribution of the right middle cerebral artery with no significant carotid stenoses and no cardioembolic source He had a history of hypertension and hyperlipidemia and at the time of the stroke was taking hydrochlorothiazide, lisinopril, atorvastatin, and aspirin (325 mg/d) It would be reasonable to change from his current aspirin regimen to which of the following?
A Aspirin, 1300 mg/d
B Aspirin, 325 mg/d plus clopidogrel, 75 mg/d
C Aspirin, 25 mg plus extended-release dipyridamole, 200 mg; 1 capsule 2 times a day
D Aspirin, 25 mg 2 times a day plus immediate-release dipyridamole, 75 mg 4 times daily
E Warfarin, 5 mg /d, adjusted to maintain an INR in the range of 2.0 to 3.0
Correct Answer: The correct answer is C This patient had a stroke while taking aspirin in the US Food and Drug Administration (USFDA)-recommended range (50 mg /d to 325 mg /d) It is reasonable to recommend a change to either clopidogrel or aspirin/extended-release dipyridamole, both of which reduced the risk of stroke relative to aspirin in controlled trials The addition of aspirin to clopidogrel provided no additional benefit to patients at high risk for cerebrovascular disease compared with clopidogrel alone but increased the risk of life-threatening and major bleeding events Extended-release dipyridamole is preferred over immediate-release dipyridamole because of the latter's erratic absorption Warfarin is no more effective than aspirin in patients with no cardioembolic source
10 In a patient with symptomatic, 80% stenosis of the right extracranial ICA, which of the following would be the most compelling reason to consider medical management rather than right carotid endarterectomy?
A The patient has had a nondisabling stroke within the past week
B The patient has had no symptoms for 5 years
C The patient is female
D There is a noncritical tandem lesion in the intracranial right ICA
E There is an ulcerative plaque in the extracranial right ICA
Correct Answer: The correct answer is B North American Symptomatic Carotid Endarterectomy Trial patients were enrolled within 120 days of the index transient ischemic attack (TIA) or nondisabling stroke; European Carotid Surgery Trial patients were enrolled within 6 months Post hoc analysis reveals that for patients with symptomatic stenosis of more than 70%, the maximum benefit of surgery was reached by 3 years, with the event curves largely parallel thereafter This suggests (but is not proof) that the surgery is less likely to be beneficial in patients who have been asymptomatic for at least 3 years The perioperative stroke rate was no higher in patients who had an endarterectomy 3 to 30 days after a nondisabling stroke than it was in patients who had surgery after 30 days, so there is no reason to delay surgery in these patients The numbers needed to treat were lower in patients with ipsilateral intracranial carotid disease, suggesting that carotid endarterectomy is beneficial even in the setting
of a noncritical intracranial tandem lesion (no conclusions can be drawn regarding critical tandem lesions because those patients were excluded from the trial) Patients with an ulcerative plaque in the setting of a high-grade
Trang 4stenosis were at particularly high risk of stroke, so endarterectomy is likely to be especially beneficial in this group
Benefits of carotid endarterectomy were similar for men and women in the symptomatic trials
11 A 78-year-old woman with hypertension and hyperlipidemia has had a gradual deterioration in memory over
the past 2 or 3 years Her family reports that she frequently loses her train of thought while talking and she never
seems to finish anything she starts She scores 20/30 on the Mini-Mental State Examination Her examination is
notable for inattention, impersistence, word-finding problems, and poor short-term memory, with normal cranial
nerves and absence of focal motor or sensory deficits Her deep tendon reflexes are diffusely brisk but not
pathological An MRI scan of the brain reveals diffuse white matter hyperintensities, and blood tests show no
evidence of systemic causes of dementia Which of the following is the most likely diagnosis?
A Alzheimer's disease
B Dementia with Lewy bodies
C Mixed vascular dementia/Alzheimer's disease
D Vascular cognitive impairment, no dementia
E Vascular dementia
Correct Answer: The correct answer is C The slow, insidious progression of primary memory impairment is
typical of Alzheimer's disease, but the prominent executive dysfunction (on both history and examination) and the
MRI findings typical of chronic ischemia in a patient with risk factors for stroke suggest a component of vascular
dementia
12 A 55-year-old man presents to the physician for evaluation and treatment of stroke risk factors He suffered a
right middle cerebral artery distribution infarct 4 weeks ago and is improving neurologically with the help of
physical therapy He has a history of type 1 diabetes mellitus for which he takes insulin There is no history of
hyperlipidemia or hypertension He is a nonsmoker His mother died of a stroke at age 80 Blood pressure is 128/80
mm Hg His fasting glucose is 150 mg /dL with a glycosylated hemoglobin of 6.5% LDL is 80 mg/dL Which of
the following statements is most appropriate in counseling this patient?
A Tight control of serum glucose has been shown to decrease the risk of stroke
B Studies have not demonstrated an independent effect of diabetes on ischemic stroke risk
C His diabetes conveys a relative ischemic stroke risk more than twice that of normal controls
D He should be placed on an antihypertensive agent
E He should aim for a fasting glucose less than 90 mg /dL
Correct Answer: The correct answer is C Diabetes mellitus has been shown to be an independent risk factor for
stroke and other vascular disease However, tight glucose control has not been conclusively shown to reduce the
risk of stroke A large population-based study has found that diabetes conveys a relative risk of ischemic stroke of
2.26 The American Diabetic Association recommends fasting glucose to be less than 120 mg /dL Blood pressure
recommendations are stricter for diabetics and should be less than 130/80 mm Hg Based on that recommendation,
this patient would not require antihypertensive medications but does need better glucose control
13 A 68-year-old woman presents with the abrupt onset of left hemiparesis and left hemineglect Her past medical
history is remarkable for hypertension and hyperlipidemia Findings from her examination reveal dense left
hemiparesis, a right gaze preference, and left cortical sensory loss with neglect CT of the head performed 6 hours
after the onset of symptoms reveals a wedge-shaped area of low attenuation developing within the right insula
Carotid ultrasound demonstrates 85% stenosis of the right internal carotid artery and 50% stenosis of the left
internal carotid She is admitted to the hospital and started on aspirin Which of the following cardiovascular
conditions is more likely in this patient when compared with a patient with a similar infarct on the left side of the
brain?
A Myocardial infarction
B Aortic dissection
C Cardiac dysrhythmia
D Valvular vegetation
E Patent foramen ovale
Correct Answer: The correct answer is C Patients with right insular infarcts are more likely to develop autonomic
aberrations with potentially serious cardiac dysrhythmias and sudden death These patients should be monitored for
severe dysrhythmias, particularly ventricular tachycardia The other cardiac conditions listed are not more likely to
occur in right insular infarcts when compared with those of the left insula
14 Which of the following organizational features differentiates a comprehensive trauma center from a
comprehensive stroke center?
A The presence of a multi-tiered system in trauma centers
B Employment of guidelines for initiating preventive therapies at stroke centers
C Coordination with the emergency medical services system at stroke centers
Trang 5D Involvement of multiple medical disciplines in trauma centers
E Ability to triage the patient for specialized care depending on the clinical problem at stroke centers
Correct Answer: The correct answer is B Both comprehensive trauma centers and comprehensive stroke centers rely on a multi-tiered system of triage to supply primary and comprehensive levels of care Both depend upon integration with emergency medical services in order for the patient to have access to appropriate care as quickly as possible Both stroke and trauma require the integration of multiple disciplines including medicine, surgery, radiology, nursing, and pharmacy Because stroke is often a recurring disease, stroke centers must also focus on risk factor reduction through the employment of evidence-based guidelines to initiate preventive therapies
15 In a 78-year-old man with hypertension, hyperlipidemia, and diabetes, which of the following is least likely to result in embolic stroke?
A Aortic atheroma (5 mm)
B Aortic valve disease
C Atrial fibrillation
D Cardiomyopathy (ejection fraction = 25%)
E Mitral annular calcification
Correct Answer: The correct answer is B Atrial fibrillation increases the risk of stroke across all age groups by a factor of 4 to 6 Cardiomyopathy is the second most common cause of cardioembolic stroke, with a 3-fold increase
in relative risk Mitral annular calcification is associated with a 2.1-fold increase in stroke risk Retrospective and prospective studies have shown an annual stroke risk of 11.9% to 33% in patients with aortic atheromatous plaques greater than 4 mm to 5 mm In the absence of associated mitral valve disease or atrial fibrillation, systemic embolism is uncommon in patients with aortic valve disease
16 A 50-year-old man visits his physician for a routine physical examination The patient has a 40-pack-year history of smoking and continues to smoke 2 packs of cigarettes per day His past medical history is negative for heart disease or other serious medical illness His mother recently died of a "massive stroke," but there is no other family history of stroke His blood pressure is 140/80 mm Hg, and the remainder of the physical examination is normal In counseling this patient, which of the following is the most accurate statement?
A Smoking confers a 50% increase in the overall risk of stroke compared with nonsmoking
B The increased risk of stroke from smoking applies primarily to intracerebral hemorrhage
C The patient's smoking habits will have no significant effect on his spouse's risk of stroke
D If the patient quits smoking now, it will take 10 to 15 years before his stroke risk decreases to that of nonsmokers
E The patient's risk of stroke would not decrease if he reduced his daily cigarette consumption to 4 cigarettes per day
Correct Answer: The correct answer is A Smoking confers a 50% increase in the overall risk of stroke when compared with nonsmoking The increased risk of stroke applies to both ischemic and primary hemorrhagic stroke The risk of stroke related to smoking decreases to that of nonsmokers within 2 to 4 years after cessation Nonsmoking spouses of smokers have an increased risk of stroke compared with nonsmoking spouses of nonsmokers The risk of stroke is directly proportional to the quantity of cigarettes smoked
17 A 62-year-old woman with hypertension and hyperlipidemia suddenly developed aphasia and weakness of the right face and arm The symptoms resolved within 10 minutes, and the findings from her examination were normal when she was seen in the emergency department 2 hours later What is her approximate risk of having a stroke in the next 2 days?
A 0.01%
B 0.1%
C 5%
D 15%
E 30%
Correct Answer: The correct answer is C The risk of stoke is highest soon after the index TIA with a nearly 11% risk of having a stroke over the next 90 days, and about half of these occur over the first 2 days
18 A 70-year-old retired white right-handed female college professor had a vertebro-basilar infarct with residual dysarthria, gait ataxia, right hemiparesis, and hemisensory loss Her MRI scan of the brain shows areas of restricted diffusion in the left thalamus and midbrain An MRA shows intracranial atheromatous disease in multiple vessels, including the basilar artery Her past medical history is remarkable for hypertension, hyperlipidemia, and type 2 diabetes mellitus She consumes 1 glass of wine per day Her family history is significant for a maternal grandmother with Alzheimer's disease with onset at age 85 and a paternal cousin with Down's syndrome Which of the following is the most significant risk factor for the development of dementia is this patient?
A Alcohol use
Trang 6B Family history of dementing illness
C Education level
D Mechanism of stroke
E Left thalamic infarction
Correct Answer: The correct answer is E Her moderate alcohol use and advanced education would not put her at
increased risk for dementia Low educational achievement increases risk Similarly, the mechanism of stroke
(thrombotic or atheroembolic) would not determine her risk of dementia The location of the infarct increases risk if
the infarct is in the dominant hemisphere, dominant thalamus, or deep frontal regions The number and mean
volume of infarcts and infarcted tissue also increase risk of dementia
19 A 70-year-old woman presents to the physician with a history of transient visual loss yesterday She is
previously healthy and takes only a multivitamin Yesterday, she was watching television and experienced a
sensation "like a shade was coming down" over her left eye There was no pain or other neurological symptom
Today, findings from her neurological examination are normal; blood pressure is 120/70 mm Hg, heart rate is
100/min irregularly irregular The erythrocyte sedimentation rate is 15 An ECG reveals atrial fibrillation An
echocardiogram reveals normal chamber size and normal cardiac valves No left atrial thrombus is identified The
carotid ultrasound shows no ICA stenosis Which of the following statements is the most accurate concerning her
risk of future stroke?
A There is insufficient risk to warrant the use of warfarin
B Her risk of stroke over the next 5 years is greater than 20%
C In this setting, her risk of stroke is less because she is a woman
D The absence of left atrial thrombus indicates that the TIA was not due to atrial fibrillation
E Warfarin therapy would reduce her stroke risk by 20%
Correct Answer: The correct answer is B Using the table supplied in Figure 2-3, based on age, sex, blood pressure,
and history of TIA, her risk of stroke in the next 5 years is 24% This clearly warrants the use of warfarin, which is
estimated to reduce risk of stroke by 68% in patients with nonvalvular atrial fibrillation Her risk of stroke is
actually increased in this setting because she is a woman The absence of a left atrial thrombus does not exclude the
atrial fibrillation as the etiology of her TIA
20 Which of following features differentiates a primary stroke center from a comprehensive stroke center?
A Technology and support to administer tissue plasminogen activator (tPA)
B Availability of advanced interventional radiologye
C Rapid evaluation and treatment of the patient
D Coordination of effort with multiple specialties
E Defined stroke unit
Correct Answer: The correct answer is B The "hub and spoke" model of stroke care refers to multiple primary
stroke centers (the spokes) where patients are evaluated, treated, and stabilized and only sent on to a comprehensive
stroke center (the hub) if more complex evaluation or therapy is required, including interventional radiology or
specialized surgery Both primary stroke centers and comprehensive stroke centers require prompt evaluation and
treatment of the patient and coordination of effort with multiple specialties Both centers could administer tPA if it
were indicated Both primary stroke centers and comprehensive stroke centers need to have a defined stroke unit,
which need not be geographically separate
21 A 69-year-old man with hypertension and diabetes presents with the acute onset of gait and right limb ataxia,
dysarthria, diplopia, and left hemiparesis His past medical history is also remarkable for sick sinus syndrome, for
which he underwent placement of a ventricular pacemaker 3 months ago CT of the head without contrast reveals a
developing infarct in the right cerebellum 12 hours after onset of symptoms without evidence of mass effect ECG
shows a paced rhythm with a rate of 85/min There is no evidence of myocardial ischemia Which of the following
is an accurate statement concerning this patient's clinical presentation or treatment?
A The presence of atrial fibrillation may be obscured electrographically by the presence of the pacemaker
B An atrial rate greater than 220/min is not an independent risk factor for stroke
C Misplaced pacemaker leads would be an unlikely source of emboli
D Anticoagulation with warfarin is warranted when stroke occurs in patients with pacemakers and normal sinus
rhythm
E Dual-chamber pacing would carry a lower risk of subsequent stroke than ventricular pacing
Correct Answer: The correct answer is A An increased incidence of atrial fibrillation occurs in patients undergoing
pacemaker placement for sick sinus syndrome and atrioventricular block The presence of atrial fibrillation may be
obscured electrographically by the pacemaker, thus masking a risk factor for embolic stroke requiring
anticoagulation The risk of stroke was not found to be lower in dual-chamber pacing versus patients undergoing
ventricular pacing alone (Glotzer et al, 2003) Anticoagulation is not routinely required in the presence of a
Trang 7pacemaker unless an embolic source or cardiac dysrhythmia is demonstrated Patients with very high atrial rates (greater than 220) are 2 times as likely to die or have stroke and 6 times more likely to develop atrial fibrillation Glotzer, TV, Hellkamp AS, Zimmerman J, et al Atrial high rate episodes detected by pacemaker diagnostics predict death and stroke: report of the Atrial Diagnostics Ancillary Study of the Mode Section Trial (MOST) Circulation 2003;107:1614-1619
22 Which of the following medications has been shown to reduce the risk of stroke (relative to placebo) in patients with atrial fibrillation?
A Aspirin
B Clopidogrel
C Extended-release dipyridamole
D Immediate-release dipyridamole
E Ticlopidine
Correct Answer: The correct answer is A Although the risk reduction is only about a third of what is achieved with warfarin, aspirin does reduce the risk of stroke in patients with atrial fibrillation by 20% relative to placebo Aspirin use is recommended in patients with atrial fibrillation who have a low risk of embolism, and also when there is a major contraindication to warfarin or other antithrombotic therapy The effectiveness of other antiplatelet agents in atrial fibrillation is not known
23 A 60-year-old man presents to his physician for counseling 6 months after undergoing a left carotid endarterectomy for an asymptomatic 90% stenosis He has no previous history of stroke, TIA, or heart disease He
is extremely obese (body mass index = 45 kg /m2) with predominantly abdominal obesity He has type 2 diabetes mellitus, and his blood pressure is 140/85 mm Hg His fasting glucose is 150 mg /dL, and his LDL cholesterol is
150 In addition to counseling for his other risk factors, which of the following is the most accurate statement concerning his morbid obesity?
A The patient should lose weight as obesity is an independent risk factor for future stroke
B Abdominal adiposity increases circulating free fatty acids, which may lower blood pressure
C Weight loss can improve diabetic and blood pressure control and thereby reduce risk of stroke
D The body mass index is a better correlate of disease risk than abdominal circumference
E Morbid obesity raises circulating high-density lipoprotein (HDL) levels
Correct Answer: The correct answer is C Obesity has not been shown to be an independent risk factor for stroke It
is, however, associated with increased risk of several health conditions that increase the risk of stroke These conditions include hypertension, diabetes mellitus, and hyperlipidemia Abdominal adiposity as measured by abdominal circumference may be a better measure of disease than body mass index Abdominal obesity is associated with increased levels of circulating free fatty acids, which have a variety of adverse effects These include elevated blood pressure, lowered circulating HDL levels, and reduced pancreatic beta cell insulin production Weight loss can produce reduced risk of stroke, primarily by reducing the comorbidities of hypertension, diabetes, and dyslipidemia
24 Which of the following is associated with a reduced risk of vascular cognitive impairment?
A Heavy alcohol use
B Hypertension
C Male sex
D More years of education
E Older age
Correct Answer: The correct answer is D Demographic variables associated with increased risk of vascular dementia and vascular cognitive impairment, no dementia include older age, male sex, and fewer years of completed education Hypertension is associated with stroke, white matter disease, and subsequent cognitive decline Heavy alcohol consumption has been associated with both cognitive impairment and stroke, although low
to moderate consumption is associated with cognitive health
25 Among patients with significant carotid stenosis, endarterectomy is likely to be most beneficial in patients whose TIAs are characterized by which of the following?
A Amaurosis fugax
B Aphasia and facial droop
C Ataxic hemiparesis
D Pure hemiparesis
E Pure hemisensory loss
Correct Answer: The correct answer is B Post hoc analysis indicates that the relative risk reduction resulting from endarterectomy is greatest in patients with nonlacunar syndromes (eg, aphasia and hemiparesis) and least in
Trang 8patients with lacunar syndromes (eg, pure hemiparesis and pure hemisensory loss) Patients whose TIAs consist of
amaurosis fugax may be at lower risk for subsequent stroke than patients with hemispheric TIAs
26 Which of the following is the most accurate summary of risks and benefits of moderate-intensity oral
anticoagulant therapy (INR = 2.0-3.0) after acute myocardial infarction?
A No significant difference in risk of stroke, myocardial infarction, or major bleeding
B No significant difference in risk of stroke or myocardial infarction, increased risk of major bleeding
C No significant difference in risk of stroke, reduced risk of myocardial infarction, no significant difference in risk
of major bleeding
D Reduced risk of stroke and myocardial infarction, increased risk of major bleeding
E Reduced risk of stroke and myocardial infarction, no significant difference in risk of major bleeding
Correct Answer: The correct answer is D Moderate-intensity oral anticoagulant therapy was associated with a
significantly reduced risk of myocardial infarction (hazard ratio = 0.48, 95% confidence interval 0.36-0.63) and
stroke (hazard ratio = 0.47, 95% confidence interval = 0.270.71), but a 7.7fold (95% confidence interval = 3.3
-18) increase in bleeding
27 Which of the following was a quality measure for stroke identified by the Health Care Financing
Administration (HCFA) in its first large-scale effort to develop "process of care" measures in the 1990s?
A Warfarin prescription for atrial fibrillation
B Sublingual nifedipine prescription for patients with acute stroke
C Administration of tPA for patients with ischemic stroke
D 3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor prescription for patients with lacunar
stroke
E Subcutaneous heparin administration for deep vein thrombosis prophylaxis
Correct Answer: The correct answer is A The first large-scale effort to develop process of care measures was in the
1990s, when HCFA developed three quality measures for stroke: (1) warfarin prescription for atrial fibrillation; (2)
antithrombotic medication prescribed at discharge after ischemic stroke; and (3) avoidance of sublingual nifedipine
for patients with acute stroke
28 A 50-year-old man with hypertension, type-2 diabetes mellitus, and hyperlipidemia develops acute left-sided
chest pain ECG reveals sinus tachycardia (100/min) and acute lateral myocardial ischemia During his evaluation
in the emergency department, he develops transient right hemiparesis and aphasia, which resolves within 10
minutes Currently, findings from his neurological examination are normal A CT of the head without contrast is
negative A transesophageal echocardiogram reveals a left ventricular mural thrombus Coronary angiography does
not reveal a coronary artery lesion that is amenable to stenting Which of the following therapies is most
appropriate at this time?
A tPA
B Aspirin and tPA
C Warfarin
D Aspirin and warfarin
E Clopidogrel, aspirin, and warfarin
Correct Answer: The correct answer is D This patient has had an acute myocardial infarct and an embolic TIA
from a mural thrombus Aspirin is required for secondary prevention of myocardial ischemia but is not sufficient to
prevent additional embolic stroke Aspirin and warfarin are therefore indicated in this patient If the patient had
undergone coronary stenting, then clopidogrel should be added to warfarin and aspirin in the short term (duration of
clopidogrel therapy dependent on the type of stent used) Tissue plasminogen activator should only be used in
patients with significant neurological deficit related to cerebral ischemia It is used to improve outcome after
ischemic stroke but is not used in stroke prevention
29 A 65-year-old man presents to his physician 6 months after a stroke attributed to a right ICA occlusion He is
on aspirin therapy and has had no further ischemic events His past medical history is remarkable for multiple risk
factors for stroke including hypertension, diabetes, and hypercholesterolemia These factors appear to be well
controlled on hydrochlorothiazide, insulin, and atorvastatin, respectively He is a nonsmoker and consumes no
alcohol His lifestyle is sedentary Blood work reveals an elevated homocysteine level He is particularly interested
in dietary and "holistic" measures that might lower his risk of future stroke Which of the following would be the
most appropriate advice to the patient?
A He should start drinking 2 alcoholic beverages daily
B A sedentary lifestyle does not appear to increase stroke risk
C Folate, vitamin B12, and vitamin B6 supplementation will lower his risk of future stroke
D A low-fat diet will reduce his risk of stroke
E Higher levels of fruit and vegetable intake are associated with lower stroke risk
Trang 9Correct Answer: The correct answer is E Although mild to moderate alcohol consumption appears to protect against stroke, it is not advisable to encourage drinking in a nondrinking patient Besides concern about alcohol addiction, the use of alcohol could affect his diabetic control The patient should be encouraged to exercise regularly A meta-analysis of 23 studies linking physical activity and stroke risk has demonstrated that highly active people had a 27% lower risk of stroke or mortality than sedentary persons Although elevated homocysteine level is a marker of vascular disease, lowering the homocysteine level with vitamin therapy has not been shown to reduce risk of recurrent stroke The evidence concerning dietary fats and stroke risk is conflicting with several studies showing reduced stroke risk with high fat intake Therefore, no data support a low-fat diet in reducing stroke risk On the other hand, a diet rich in fruits and vegetables is associated with a lower ischemic stroke risk
30 An 82-year-old woman with hypertension, diabetes, hyperlipidemia, and paroxysmal atrial fibrillation has been referred to the neurologist for bilateral foot pain Her examination reveals lower extremity hyporeflexia and sensory loss with a distal-to-proximal gradient Her strength, coordination, and gait are normal Electrophysiological studies are consistent with an axonal sensorimotor polyneuropathy, and blood tests disclose no cause other than her known diabetes Which of the following approaches to stroke prophylaxis would be most appropriate for this patient?
A Aspirin
B Aspirin plus extended-release dipyridamole
C Clopidogrel
D No stroke prophylaxis unless the patient experiences a TIA or stroke
E Warfarin
Correct Answer: The correct answer is E The annual stroke rate in patients with nonvalvular atrial fibrillation is consistently lower with warfarin than with aspirin Aspirin is only considered the treatment of choice in patients younger than 65 who have no stroke risk factors, or those with lone atrial fibrillation and a stroke risk of less than 1% per year Risk factors for stroke in patients with nonvalvular atrial fibrillation include increasing age (per decade above 65 years), history of hypertension, and history of diabetes Thus, this patient has two risk factors in addition to her age Nothing about her history or examination indicates a contraindication to warfarin Clopidogrel and dipyridamole have been not been adequately studied in patients with atrial fibrillation
31 A 60-year-old man presents to his physician 3 months after a lacunar stroke within the left internal capsule, resulting in a mild right hemiparesis His past medical history is remarkable for hypertension, type 2 diabetes mellitus, and hypercholesterolemia He takes hydrochlorothiazide, lisinopril, metformin, and niacin His blood pressures have varied from 115/70 mm Hg to 125/75 mm Hg Fasting blood sugar is 115 with glycosylated hemoglobin of 4% His LDL is 150 mg/dL and HDL is 30 mg /dL Triglycerides are 160 mg /dL Which of the following is the most accurate statement concerning risk factor management of this patient?
A Stroke risk would be lowered by more aggressive blood pressure control
B Cholesterol-lowering agents should be prescribed for a target LDL less than 70 mg/dL
C An HMG-CoA reductase inhibitor may increase risk of lacunar infarction
D Available data definitively demonstrate that hyperlipidemia increases lacunar stroke risk
E The addition of a beta-blocker would reduce stroke risk
Correct Answer: The correct answer is B This patient has multiple stroke risk factors, including hypertension, diabetes, and hyperlipidemia His diabetes and hypertension are optimally controlled at this time, and further attempts to lower blood pressure and blood glucose are unlikely to affect stroke risk The relationship of hyperlipidemia and stroke risk has never been firmly established, particularly for small vessel cerebrovascular disease Given the patient's high-risk status for coronary heart disease, he would benefit from use of an HMG-CoA reductase inhibitor with a target of LDL less than 70 mg /dL
32 A 58-year-old man presents to the emergency department 8 hours after the abrupt onset of aphasia and right hemiparesis A CT head scan without contrast demonstrates an area of low attenuation within the distribution of the left middle cerebral artery (MCA) A thorough cardiac evaluation is negative He has moderate intracranial and extracranial atheromatous disease, which is not deemed eligible for surgical intervention His past medical history
is remarkable for numerous stroke risk factors, including hypertension and hypercholesterolemia He is also a heavy drinker of alcoholic beverages (greater than 100 gm/d), particularly on weekends In addition to improved control of his hypertension and hypercholesterolemia, which of the following statements is most accurate with respect to alcohol use and the risk of future stroke?
A The patient's current level of alcohol use is likely beneficial in reducing risk of future stroke
B His current level of alcohol use increases his risk of hemorrhagic but not ischemic stroke
C Excess alcohol consumption may elevate blood pressure and produce atrial fibrillation
D The patient may continue his current level of alcohol consumption if he drinks red wine exclusively
E The patient should be advised to discontinue alcohol consumption during the week but can continue his weekend drinking without increased risk of stroke
Trang 10Correct Answer: The correct answer is C Mild to moderate alcohol use (less than 24 gm/d) may be beneficial in
reducing the risk of stroke by various mechanisms Heavy alcohol use (greater than 60 gm/d) and binge drinking
increase the risk of both ischemic and hemorrhagic stroke by a variety of mechanisms Excess alcohol may raise
blood pressure and produce cardiac dysrhythmias, including atria1 fibrillation It may produce cardiomyopathy and
affect the production of coagulation factors by the liver Red wine may be of some benefit over spirits and beer
although this is disputed Patients with a history of heavy alcohol use should undergo abuse counseling, and those
who already abstain should not be advised to start drinking
33 A 75-year-old right-handed man is brought to the physician by his wife for evaluation of cognitive and
behavioral changes His past medical history is remarkable for hypertension, hyperlipidemia, and a 60-pack-year
history of smoking He had a "small stroke" 1 year ago, which produced transient right hemisensory loss His
medications include atenolol, atorvastatin, and hydrochlorothiazide His wife states that for the last year he has
been much less interactive He is no longer interested in his hobbies and prefers to sit in front of the television
instead He is easily distracted and frequently has to be redirected to finish a task He has to be reminded to shave
and bathe He sometimes needs assistance using simple kitchen appliances She no longer allows him to drive, as
he was previously getting lost and making inappropriate turns He no longer is interested in or able to manage the
household accounts or investments The patient himself does not recognize that he is having any difficulties On
examination blood pressure is 160/95 mm Hg, heart rate is 65/min regular, and temperature is 36.5°C He is alert
but abulic He scores 22/30 on the Mini-Mental State Examination He cannot spell the word "world" backwards
Immediate recall of three objects is impaired, and he cannot remember them after 5 minutes He is disoriented with
respect to date and place His language examination is normal, and the remainder of the neurological examination
is unremarkable Which of the following historical or clinical features is most helpful in differentiating vascular
cognitive impairment from Alzheimer's disease in this patient?
A Impairment of executive function
B Preserved language function
C Impaired short-term memory
D Impairment of daily functional abilities
E Impaired insight
Correct Answer: The correct answer is A The prominent impairment of executive function (eg, planning,
organizing, multitasking) is typical of vascular cognitive impairment Abulia, psychomotor slowing,
inattentiveness, and distractibility are also typically seen in vascular cognitive impairment Short-term memory
impairment is common with all dementias, as are impairment of activities of daily living and impairment of insight
Therefore, these latter features would not distinguish vascular cognitive impairment from Alzheimer's disease
Language may be preserved in either type of dementia early on and would not distinguish vascular cognitive
impairment from Alzheimer's disease The fact that the cognitive impairment was linked temporally to the history
of stroke is also a helpful distinguishing factor
34 Which of the following is the most common manifestation of a TIA in the distribution of the left ICA?
A Amaurosis fugax
B Aphasia
C Arm weakness and numbness
D Leg weakness and numbness
E Vertigo
Correct Answer: The correct answer is C Contralateral arm weakness and sensory symptoms are the most common
symptoms of TIAs in the carotid distribution, occurring in 67% to 70% of patients, whereas leg weakness occurs in
25% to 35% of patients Aphasia occurs in about 50% of patients with left ICA distribution TIA Isolated vertigo is
not consistent with a TIA in the carotid distribution
35 Which of the following is an absolute requirement for an acute stroke response team as defined in the JCAHO
certification process?
A At least 1 team member must be a neurologist
B Neurosurgical support must be available on-site
C The majority of the team members must be physicians
D The team must be available 24 hours a day
E The team must employ nationally standardized written care protocols
Correct Answer: The correct answer is D The JCAHO certification process allows some flexibility among sites
The unifying factor is that the team must be available 24 hours a day and readily called into action The team must
include a physician, but not necessarily a neurologist On-site neurosurgical services are not required if provisions
are in place for urgent transfer of patients with acute stroke requiring neurosurgical intervention The content of
written care protocols may be determined locally as long as it falls within evidence-based national guidelines