46. A 67-year-old woman with a history of type 2 diabetes mellitus and atrial fibrillation presents to the emergency room with left body weakness and slurred speech. The onset was sudden while she was brushing her teeth 1 hour ago, and she was brought immediately to the emergency room. She denies word-finding difficulties, dysesthesia, and headache. She is taking warfarin. Physical examination findings include blood pressure of 205/90 mm Hg and irregularly irregular heartbeat. There is left-side neglect with slurred speech. There is a corticospinal pattern of weakness of the left body, with the face and upper extremity being worse than the lower extremity. Routine chemistries and cell counts are normal. Her international normalized ratio (INR) is 1.8. Which of the following is the most appropriate first step in management?
a. Administer tissue plasminogen activator.
b. Call a vascular surgery consult for possible endarterectomy.
c. Order a brain computed tomography (CT).
d. Order a cerebral angiogram.
e. Start heparin.
47. A 74-year-old man is diagnosed with an acute stroke. A right middle cerebral artery occlusion is demonstrated by magnetic resonance angio-gram shown below. Which of the following is the most likely cause of this patient’s present condition?
a. Atherosclerosis
b. Fibromuscular dysplasia
c. Mitral valve prolapse
d. Arterial dissection
e. Meningovascular inflammation
48. A 52-year-old woman with diabetes awakens with right body weakness. Examination at the hospital indicates relatively symmetric upper motor neuron pattern of weakness involving the face, arm, and leg. There are no sensory abnormalities. Language is preserved. A stroke associated with this presentation is most likely with damage to which of the following?
a. Internal capsule
b. Cerebellum
c. Putamen
d. Caudate
e. Amygdala
49. Following cardiac catheterization, a 60-year-old right-handed man acutely develops a loss of sensation involving the entire left side of his body (face, arm, and leg). Which of the following structures has most likely been damaged?
a. Internal capsule
b. Thalamus
c. Hippocampus
d. Globus pallidus
e. Pons
50. A 61-year-old man with a history of hypertension has been in excellent health until he presents with vertigo and unsteadiness lasting for 2 days. He then develops nausea, vomiting, dysphagia, hoarseness, ataxia, left facial pain, and right-sided sensory loss. There is no weakness. On examination, he is alert, with a normal mental status. He vomits with head movement. There is skew deviation of the eyes, left ptosis, clumsiness of the left arm, and titubation. He has loss of pin and temperature sensation on the right arm and leg and decreased joint position sensation in the left foot. He is unable to walk. Magnetic resonance imaging (MRI) in this patient might be expected to show which of the following?
a. Basilar artery tip aneurysm
b. Right lateral medullary infarction
c. Left lateral medullary infarction
d. Left medial medullary infarction
e. Right medial medullary infarction
51. A 50-year-old man had a brainstem stroke following a vertebral artery dissection secondary to an acute sports-related injury. This patient might be expected to develop dysphagia secondary to involvement of which of the following structures?
a. Nucleus solitarius
b. Nucleus and descending tract of cranial nerve (CN) V
c. Nucleus ambiguus
d. Lateral spinothalamic tract
e. Inferior cerebellar peduncle
52. Occlusion of which of the following arteries typically produces Wallenberg (lateral medullary) syndrome?
a. Basilar artery
b. Vertebral artery
c. Superior cerebellar artery
d. Anterior inferior cerebellar artery (AICA)
e. Anterior spinal artery
53. A 75-year-old man with a history of recent memory impairment is admitted with headache, confusion, and a left homonymous hemianopsia. He has recently had two episodes of brief unresponsiveness. There is no history of hypertension. CT scan shows a right occipital lobe hemorrhage with some subarachnoid extension of the blood. An MRI scan with gradient echo (susceptibility) sequences reveals foci of hemosiderin in the right temporal and left frontal cortex. Which of the following is the most likely cause of this patient’s symptoms and signs?
a. Gliomatosis cerebri
b. Multi-infarct dementia
c. Mycotic aneurysm
d. Amyloid angiopathy
e. Undiagnosed hypertension
54. A 22-year-old male abuser of intravenous heroin has been having severe headaches during sexual intercourse. Within a few minutes of one headache, he develops right-sided weakness and becomes stuporous. His neurologic examination reveals neck stiffness as well as right arm and face weakness. An unenhanced emergency CT scan reveals a 3-to-4 cm lesion in the cortex of the left parietal lobe. The addition of contrast enhancement reveals two other smaller lesions in the right frontal lobe but does not alter the appearance of the lesion in the left parietal lobe. Which of the following diagnostic studies is most likely to establish the basis for this patient’s neurologic deficits?
a. Human immunodeficiency virus (HIV) antibody testing
b. Cerebrospinal fluid (CSF) examination
c. Electroencephalography (EEG)
d. Nerve conduction studies (NCS)
e. Cardiac catheterization
55. A 52-year-old right-handed woman who has abused intravenous drugs for many years has an HIV antigen test that is positive. CD4+ T-lymphocyte count is normal. A brain CT scan reveals several hemorrhagic lesions. NCS reveal generalized slowing in the legs, and EEG exhibits focal slowing over the left parietal lobe. Cardiac catheterization suggests aortic valve disease, and the patient’s CSF is xanthochromic. Which of the following is the probable site of injury in the central nervous system (CNS)?
a. An arterial wall
b. The ventricular endothelium
c. The pia arachnoid
d. The dura mater
e. The perivenular space
56. A 35-year-old man presented to the emergency room with the acute onset of right body weakness. A diffusion-weighted MRI was positive and is in part shown below. Further imaging sequences indicated a small left frontal intraparenchymal hemorrhage. Within 1 day of admission, the patient’s right-sided weakness began to abate, and within 1 week it almost completely resolved. On the sixth day of hospitalization, the patient abruptly lost consciousness and exhibited clonic movements starting in his right side and generalizing to his left side. The movements stopped within 3 minutes, but he had residual right-sided weakness for 24 hours. A head CT scan was unchanged from admission. The most appropriate treatment to institute involves which of the following?
a. Heparin
b. Recombinant tissue plasminogen activator (r-TPA)
c. Lamotrigine
d. Levetiracetam
e. Warfarin
57. A 27-year-old woman presents to the emergency room following a generalized tonic-clonic seizure that began focally in her left lower extremity. Although the seizure stopped within 1 minute, there was persistent weakness of the left lower extremity lasting several hours. Further testing revealed a small arteriovenous malformation near the motor cortex. Focal weakness lasting for 24 hours following a motor seizure is most likely attributable to which of the following?
a. Intracerebral hemorrhage
b. Subarachnoid hemorrhage
c. Encephalitis
d. Todd paralysis
e. Hyponatremia
58. A 16-year-old girl with complex partial seizures and mild mental retardation has a birthmark consisting of deep red discoloration extending over her forehead and left upper eyelid. A CT scan of her brain would be likely to reveal which of the following?
a. A hemangioblastoma
b. A Charcot-Bouchard aneurysm
c. An arteriovenous malformation
d. A leptomeningeal angioma
e. A fusiform aneurysm
59. A 72-year-old retired school teacher has the abrupt onset of right face and hand weakness, disturbed speech production, and a right homonymous hemianopsia. This is most likely attributable to occlusion of which of the following arteries?
a. Left middle cerebral artery
b. Left anterior cerebral artery
c. Left vertebrobasilar artery
d. Right anterior choroidal artery
e. Left posterior inferior cerebellar artery (PICA)
60. A 39-year-old woman has diplopia several times a day for 6 weeks. She consults a physician when the double vision becomes unremitting and also mentions a dull pain behind her right eye. When a red glass is placed over her right eye and she is asked to look at a flashlight off to her left, she reports seeing a white light and a red light. The red light appears to her to be more to the left than the white light. Her right pupil is more dilated than her left pupil and responds less briskly to a bright light directed at it than does the left pupil. Before any further investigations can be performed, the woman develops the worst headache of her life and becomes stuporous. Her physician discovers that she has marked neck stiffness and photophobia. The physician performs a transfemoral angiogram. This radiologic study is expected to reveal that the woman has which of the following?
a. An arteriovenous malformation
b. An occipital astrocytoma
c. A sphenoidal meningioma
d. A pituitary adenoma
e. A saccular aneurysm
61. A 43-year-old man presents with a left CN III deficit and headache. The ocular symptoms began with papillary dilation and then progressed to oculomotor impairment. Which of the following is the most likely site of the lesion responsible for this presentation?
a. Anterior communicating artery
b. Posterior communicating artery
c. Anterior cerebral artery
d. Brainstem white matter
e. Posterior cerebral artery
62. Three days after a subarachnoid hemorrhage, a patient begins to develop neck stiffness and photophobia. This is followed by left-sided weakness and hyperreflexia. Her left plantar response is upgoing. Her physician presumes that these deficits are a delayed effect of the subarachnoid blood. Which of the following is the most appropriate treatment?
a. Heparin
b. Warfarin
c. Nimodipine
d. Phenytoin
e. Carbamazepine
63. A 73-year-old man with a history of hypertension has a 10-minute episode of left-sided weakness and slurred speech. On further questioning, he relates three brief episodes in the past month of sudden impairment of vision affecting the right eye. His examination now is normal. Which of the following is the most appropriate next diagnostic test?
a. Creatine phosphokinase (CPK)
b. Holter monitor
c. Visual evoked responses
d. Carotid artery Doppler ultrasound
e. Conventional cerebral angiography
64. A 72-year-old woman with coronary artery disease and a history of cardiac artery stenting began developing episodes of transient visual loss several months ago. Each episode is restricted to her left eye and comes on suddenly. She says, “All of a sudden half of my vision is black.” Each time the vision returns within 30 minutes. There have been approximately 10 of these events within the past 3 months. These symptoms are most likely related to which of the following?
a. Retinal vein thrombosis
b. Central retinal artery ischemia
c. Posterior cerebral artery ischemia
d. Middle cerebral artery ischemia
e. Posterior ciliary artery ischemia
65. A thorough evaluation reveals that a 69-year-old patient has a symptomatic 90% stenosis of the right internal carotid artery at the bifurcation. Which of the following management options is most likely to prevent a future stroke?
a. Warfarin
b. Carotid artery angioplasty
c. Carotid endarterectomy
d. Extracranial-intracranial bypass
e. Aspirin
Questions 66 to 74
For each clinical scenario, pick the language disturbance that best explains the clinical picture. Each lettered option may be used once, more than once, or not at all.
a. Broca aphasia
b. Wernicke aphasia
c. Transcortical sensory aphasia
d. Transcortical motor aphasia
e. Anomic aphasia
f. Global aphasia
g. Conduction aphasia
h. Mixed transcortical aphasia
66. A 62-year-old man with a history of myocardial infarction awakens with a dense right-sided hemiplegia. His eyes are tonically deviated to the left, and he does not respond to threat on the right side of his visual field. He appears to be alert and responds to pain on the left side of his body. His speech is unintelligible and nonfluent, and he follows no instructions. Efforts to get him to repeat simple phrases consistently fail.
67. A 45-year-old woman with chronic atrial fibrillation discontinues warfarin treatment and abruptly develops problems with language comprehension. She is able to produce some intelligible phrases and produces sound quite fluently; however, she is unable to follow simple instructions or to repeat simple phrases. On attempting to write, she becomes very frustrated and agitated. Emergency MRI reveals a lesion of the left temporal lobe that extends into the superior temporal gyrus.
68. A 71-year-old man develops headache and slight difficulty speaking while having sexual intercourse. He has a long-standing history of hypertension, but has been on medication for more than 7 years. He makes frequent errors in finding words and follows complex commands somewhat inconsistently. The most obvious defect in his language function is his inability to repeat the simplest of phrases without making repeated errors. An emergency CT scan reveals an intracerebral hemorrhage in the left parietal lobe that appears to communicate with the lateral ventricle.
69. A 24-year-old woman abruptly loses all speech during the third trimester of an otherwise uncomplicated pregnancy. She has a history of severe migraines during which she occasionally develops a transient right hemiplegia. Her comprehension is good, and she is frustrated by her inability to speak or write. She is unable to repeat simple phrases, but she does begin to produce simple words within 5 days of the acute disturbance of language.
70. A 78-year-old man has a cardiac arrest while being treated in an emergency room for chest pain. Resuscitation is initiated immediately, but profound hypotension is observed for at least 20 minutes. A cardiac rhythm is restored, but the patient remains unconscious for the next 3 days. When he is awake, alert, and extubated, his speech is limited to repetition of words and sounds produced by those around him. He has no apparent comprehension of language and produces few sounds spontaneously. Whenever the patient is spoken to, he fairly accurately repeats what was said to him.
71. A 62-year-old man has had a left hemisphere stroke. He has impaired naming and repetition. His speech is nonfluent. Comprehension is preserved.
72. An 82-year-old man has had a slow, stepwise cognitive deterioration. A brain MRI is consistent with the diagnosis of dementia caused by multiple cerebral infarcts. Naming is impaired. Comprehension, repetition, and fluency are relatively maintained.
73. A 53-year-old woman sustains a small left frontal embolic stroke during cardiac catheterization. She has poor naming ability and is nonfluent. Comprehension and repetition are relatively preserved.
74. A 28-year-old woman is hit in the left neck while playing lacrosse. Approximately 2 hours later she begins having language difficulties. Her speech is fluent and nonsensical. She cannot understand commands, but repeats well.
46. The answer is c. (Ropper, pp 774-775.) This is a good history for cardioembolic stroke—sudden onset, cortical symptoms, atrial fibrillation, and subtherapeutic INR. The immediate goal should be to rule out an intracranial hemorrhage and confirm the diagnosis. Tissue plasminogen activator is the treatment for acute stroke in specific circumstances. However, it is not yet certain that this is a stroke. It may be an intracranial hemorrhage, which would be a contraindication for tissue plasminogen activator. Additionally, an elevated INR in a patient on warfarin is a contraindication for tissue plasminogen activator. Carotid endarterectomy is indicated for some cases when a transient ischemic attack or stroke is believed to be caused by carotid artery narrowing. It is not yet known what caused this patient’s event, and this procedure would rarely be done emergently. A cerebral angiogram would be indicated if there was a strong suspicion of an aneurysm or vascular malformation. There is no reason to believe one of these is causing the patient’s symptoms. Heparin may be indicated if there is not an intracranial hemorrhage. This must first be established by CT or MRI.
47. The answer is a. (Ropper, pp 773-778.) Atherosclerosis may produce cerebral infarction by a variety of mechanisms, including emboli to the brain and local occlusion of atheromatous vessels. Platelet emboli may form on ulcerated atheromatous plaques in major vessel walls and ascend to the brain. The atherosclerotic plaque involves subintimal proliferation of smooth muscle, fatty deposits in the intima, inflammatory cells, and excessive elaboration of the connective tissue matrix in the vessel wall. Thrombi may form on the surface of the plaque and occlude the vessel, even if the plaque is not large enough to produce substantial narrowing of the vessel. Fibromuscular dysplasia is a relatively uncommon cause of cranial vessel occlusion that develops with segmental overgrowth of fibrous and muscular tissue in the media. Meningovascular inflammation is a rare process that occurs in some infectious or inflammatory disorders, such as syphilis, tuberculous meningitis, or sarcoid.
48. The answer is a. (Ropper, pp 748-772.) Pure motor deficits are especially likely in hypertensive persons with small infarctions, called lacunae. The pure motor stroke is the most common type of lacunar stroke. The affected person usually has hemiplegia unassociated with cognitive, sensory, or visual deficits. The posterior limb of the internal capsule is the usual site of injury. The lacunae are assumed to develop because of an occlusive lesion in an arteriole that supplies the injured structure. Isolated lesions of the cerebellum may be associated with impaired coordination, but strength is generally preserved. Lesions of the caudate or putamen, which spare the internal capsule, will generally not cause weakness. They may be grossly asymptomatic or cause more subtle, possibly transient, cognitive or motor deficits. The amygdala is involved in memory formation and emotion.
49. The answer is b. (Ropper, pp 748-772.) Pure sensory strokes are most likely in the same persons who are susceptible to pure motor strokes and other lacunae. With hypertensive injury to the posteroventral nucleus of the lateral thalamus, the affected person will report contralateral numbness and tingling. During recovery from this type of stroke, paradoxical pain may develop in the area of sensory impairment. This paradoxical pain associated with decreased pain sensitivity is referred to as the thalamic pain syndrome. This style of stroke may also be secondary to a small embolus.
50. The answer is c. (Ropper, pp 748-772.) Wallenberg, or lateral medullary, syndrome is caused by infarction involving some or all of the structures located in the lateral medulla, including the nucleus and descending tract of the fifth nerve, the nucleus ambiguus, lateral spinothalamic tracts, inferior cerebellar peduncle, descending sympathetic fibers, vagus, and glossopharyngeal nerves. The patient with Wallenberg syndrome has ipsilateral ataxia and ipsilateral Horner syndrome. The trigeminal tract damage may produce ipsilateral loss of facial pain and temperature perception and ipsilateral impairment of the corneal reflex. The lateral spinothalamic damage produces pain and temperature disturbances contralateral to the injury in the limbs and trunk. Dysphagia and dysphonia often develop, with damage to the ninth and tenth nerves.
51. The answer is c. (Kandel, pp 884-885.) The nucleus ambiguus, located in the ventrolateral medulla, contains the motor neurons that contribute to the ninth (glossopharyngeal) and tenth (vagus) cranial nerves. The motor neurons of the nucleus ambiguus innervate the striated muscles of the larynx and pharynx as well as provide the preganglionic parasympathetic supply to thoracic organs, including the esophagus, heart, and lungs. Injury to this nucleus and its pathways causes hoarseness and dysphagia.
The nucleus solitarius combines afferents from CNs VII, IX, and X responsible for visceral sensation. Its projections are primarily to parasym-pathetic and sympathetic preganglionic neurons in the medulla and spinal cord.
52. The answer is b. (Ropper, pp 748-772.) Most cases of lateral medullary infarction are caused by occlusion of the vertebral artery. Several small branches of the distal vertebral artery supply the lateral medulla. In some cases, occlusion of the PICA causes this syndrome. The PICA is the last large branch of the vertebral artery, and, when it is occluded, there may also be infarction of the inferior cerebellum accompanying that of the medulla. The basilar artery supplies the entire posterior brain circulation, and an occlusion would likely cause a much more widespread stroke. The superior cerebellar artery supplies the superior portions of the cerebellum, whereas AICA supplies portions of the cerebellum and lower cranial nerves.
53. The answer is d. (Osborn, pp I[4]:72-75.) Cerebral amyloid angiopathy, or congophilic angiopathy, is the most common cause of lobar hemorrhage in elderly patients without hypertension. The deposition of β-amyloid protein (the same as that found in Alzheimer disease) in blood vessels of the brain leads to disruption of the vessel walls, which predisposes them to hemorrhage. Patients are usually more than 70 years old and may present with multiple cortical hemorrhages, with or without a history of dementia. At times, additional hemorrhages may be seen only on special imaging techniques, such as gradient echo MRI, which magnifies the effects of hemosiderin in regions of prior hemorrhage.
54. The answer is b. (Ropper, pp 684, 816.) This young man almost certainly has numerous problems associated with his intravenous drug abuse, but the cause of his current problems is most likely bleeding from a mycotic aneurysm. Aneurysms are especially likely to bleed during exertion, such as that associated with sexual intercourse or defecation. The fact that the lesion appeared largely the same on unenhanced and enhanced CT scans suggests that it is a hematoma. HIV antibody testing might reveal evidence of exposure to HIV, but, aside from establishing that the patient was at increased risk of opportunistic infections, that test would provide little insight into the cause of the acute neurologic syndrome. The CSF would be expected to be xanthochromic (yellow), with many (> 20/μL) red blood cells (RBCs), or grossly bloody, thereby providing evidence of a recent subarachnoid hemorrhage. EEG would very likely reveal an asymmetric pattern associated with the left hemispheric lesion, but this too would provide little insight into the cause of the problem. NCS would not clarify the basis for a lesion of the CNS, because they examine only structures of the peripheral nervous system. Cardiac catheterization might reveal valvular abnormalities, but these need not be associated with disease of the CNS.
55. The answer is a. (Ropper, pp 684, 816.) The most likely explanation for this patient’s deficits is bleeding from a mycotic aneurysm. This type of aneurysm is usually relatively small and might not be evident on CT scanning or even on arteriography. An arteriogram would miss the lesion if it had destroyed itself when it bled or if the aneurysmal sac was completely thrombosed. The name mycotic is misleading. It suggests a fungal etiology, but it actually refers to the appearance of these aneurysms, which tend to be multiple. These aneurysms occur with either gram-positive or gram-negative infections, but the responsible organisms usually have relatively low virulence. Mycotic aneurysms form over the cerebral convexities with subacute bacterial endocarditis. The aneurysm develops from an infected embolus originating on the diseased heart valves and lodging in the arterial wall. Bleeding from these small aneurysms is largely directed into the subarachnoid space. More virulent organisms that produce valvular heart disease are more likely to produce a meningitis or multifocal brain abscess with seeding of infected emboli to the brain. With acquired immune deficiency syndrome (AIDS), a fungus could be the causative agent, but patients with endocarditis more typically have streptococcal or staphylococcal infections. Even if mycotic aneurysms form with endocarditis, they need not inevitably become symptomatic.
56. The answer is d. (Ropper, pp 332, 334.) Anticoagulation with warfarin or heparin and thrombolysis with r-TPA or urokinase are contraindicated in anyone with an intracranial hemorrhage. Focal seizures that secondarily generalize after an intracerebral or subarachnoid hemorrhage occur frequently and are appropriately treated with an antiepileptic drug, such as levetiracetam. Lamotrigine is an anticonvulsant, but would be a very poor choice in this case because this patient needs a drug that will be immediately therapeutic. Lamotrigine must be slowly titrated over many weeks when first started because of the risk of severe rash.
57. The answer is d. (Ropper, p 309.) Weakness after seizure activity is evidence of a postictal paralysis, or Todd paralysis. Postictal weakness does not suggest bleeding or new areas of cerebrocortical damage, but imaging with CT scan is appropriate to exclude these possibilities. Postictal paralysis may last for many hours, or even days. The precise cause is unknown, but it appears to be caused by some kind of neuronal exhaustion occurring after frequent repetitive discharges. It may reflect depletion of glucose in the neurons in the epileptic focus.
58. The answer is d. (Ropper, p 985.) This patient has encephalofacial angiomatosis (Sturge-Weber syndrome), a congenital disturbance that produces facial cutaneous angiomas with a distinctive and easily recognized appearance, along with intracranial abnormalities such as leptomeningeal angiomas. Persons with the syndrome may be mentally retarded and often exhibit hemiparesis or hemiatrophy on the side of the body opposite the port-wine nevus. Both men and women may be affected, and seizures may develop in affected persons. The nevus associated with Sturge-Weber syndrome usually extends over the sensory distribution of the first division of the trigeminal nerve. The lesion usually stays to one side of the face. Affected persons will usually also have an angioma of the choroid of the eye. Intracranial angioma is unlikely if the nevus does not involve the upper face. Deficits develop as the person matures and may be a consequence of focal ischemia in the cerebral cortex that underlies the leptomeningeal angioma. Hemangioblastomas are vascular tumors seen in association with polycystic disease of the kidney and telangiectasias of the retina (von Hippel-Lindau syndrome). Charcot-Bouchard aneurysms are very small and may be microscopic. They develop in patients with chronic hypertension and most commonly appear in perforating arteries of the brain. The lenticulostriate arteries are most commonly affected. Hemorrhage from these aneurysms is likely, and the putamen is the most common site for hematoma formation. Hemorrhage may extend into the ventricles and lead to subarachnoid blood. Other locations commonly affected include the caudate nucleus, thalamus, pons, and cerebellum. The dentate nucleus of the cerebellum is especially susceptible to the formation of Charcot-Bouchard aneurysms. Fusiform aneurysms are diffusely widened arteries with evaginations along the walls, but without stalks such as occur with the typical berry-shaped structures of the saccular aneurysm. This type of aneurysm may be a late consequence of arteriosclerotic damage to the artery wall.
59. The answer is a. (Ropper, pp 748-772.) The left middle cerebral artery supplies the cortex around the sylvian fissure, as well as some of the frontal lobe structures involved in speech. The optic radiation loops through the temporal lobe on its way to the occipital cortex and is usually damaged with occlusion of the middle cerebral artery. The likely speech disorder with an injury of the left frontal lobe is a Broca aphasia. Comprehension would be expected to be largely intact, but if the patient has damage to enough of the temporal lobe cortex, a Wernicke aphasia might develop. Choroidal artery occlusions might produce focal weakness, but speech problems would be less likely. Occlusion of the PICA can produce a variety of brainstem and cerebellar signs, but this combination of deficits would be unlikely with a lesion outside the cerebral cortex. Anterior cerebral artery stroke would be expected to cause lower extremity weakness and would not affect vision, although it could result in decreased speech production. Vertebral or basilar artery occlusion would primarily affect brainstem or cerebellar structures. If either posterior cerebral artery had its blood supply compromised, there could be visual loss and a posterior (fluent) aphasia.
60. The answer is e. (Ropper, pp 808-816.) The clinical picture suggests that a saccular aneurysm has become symptomatic by compressing structures about the base of the brain and subsequently leaking. The patient has papillary dilation of the right eye and weakness of extraocular muscles, suggesting compression of CN III by the aneurysm. Aneurysms enlarge with age and usually do not bleed until they are several millimeters across. Persons with intracerebral or subarachnoid hemorrhages before the age of 40 are more likely to have their hemorrhages because of arteriovenous malformations than because of aneurysms. Aneurysms occur with equal frequency in men and women below the age of 40; however, in their 40s and 50s, women are more susceptible to symptomatic aneurysms. This is especially true of aneurysms that develop on the internal carotid on that segment of the artery that lies within the cavernous sinus. An angiogram is useful in establishing the site and character of the aneurysm. A CT scan would be more likely to reveal subarachnoid, intraventricular, or intraparenchymal blood, but it would reveal the structure of an aneurysm only if it were several (>5) millimeters across. An MRI or magnetic resonance angiography (MRA) will also reveal relatively large aneurysms. This patient had a transfemoral angiogram, a technique that involves the introduction of a catheter into the femoral artery; the catheter is threaded retrograde in the aorta and up into the carotid or other arteries of interest.
61. The answer is b. (Ropper, pp 808-816.) An aneurysm on the posterior communicating artery is especially likely to compress the oculomotor (third) nerve. Because the pupilloconstrictor fibers lie superficially on this nerve, problems with pupillary activity are routinely early phenomena. An ischemic injury to the third CN, such as that seen with diabetes mellitus, will usually spare these superficial fibers, presumably because they have a vascular supply that is fairly distinct from that of the rest of the third nerve. The pupillary response to both direct and consensual stimulation will be impaired with compression of these parasympathetic nerve fibers. This means that the pupil in the right eye will not constrict in response to light shining into either the right or the left eye. The normal pupil on the left will constrict with light shining into either the left or the right eye because the sensory input from the right eye is unimpaired. As the aneurysm enlarges, it impinges on the third-nerve fibers that supply the medial rectus muscle, weakness of which will be responsible for double vision. Lesions of the superior cerebellar artery and posterior cerebral artery can also compress the third nerve, which exits between them. It is therefore important that a complete angiogram, evaluating all four vessels, be performed in the evaluation for subarachnoid hemorrhage and third-nerve palsy.
62. The answer is c. (Ropper, pp 808-816.) Vasospasm is a relatively common complication of subarachnoid blood and may result in stroke. Nimodipine is used because it decreases the probability of stroke, but it does not prevent it completely. Anticoagulation with heparin or warfarin worsens the patient’s prospects because it increases the risk of additional bleeding. Antiepileptic drugs, such as phenytoin and carbamazepine, may reduce the risk of seizure associated with subarachnoid blood and are sometimes given prophylactically. This patient does not have evidence of seizures, however.
63. The answer is d. (Ropper, pp 778-787.) This patient is experiencing the classical symptoms of extracranial internal carotid artery disease, which include episodes of ipsilateral transient monocular blindness (amaurosis fugax) and contralateral transient ischemic attacks consisting of motor weakness. Patients with symptomatic extracranial carotid artery disease have a high likelihood of going on to develop strokes (approximately 26% over 2 years on medical therapy). The appropriate test to confirm the suspicion of carotid stenosis is a Doppler ultrasound of the carotid arteries. This test utilizes the fact that sound waves will bounce back from particles moving in the bloodstream—primarily RBCs—at a different frequency depending on the velocity and direction of the blood flow. A great deal of important information about the structure of the blood vessel can be obtained in this way. Although angiography can also provide this information, it is invasive, carries a risk of causing a stroke, and is more expensive. MRI and MRA would also be an appropriate next step in evaluation, but is not one of the answer choices.
64. The answer is b. (Ropper, pp 225, 233.) The presumed mechanism of transient monocular blindness in carotid artery disease is embolism to the central retinal artery or one of its branches. Although classic teaching has emphasized the role that cholesterol emboli play in causing this blindness, it has been noted that cholesterol emboli (Hollenhorst plaques) may be seen on funduscopic examination even of asymptomatic individuals. Retinal vein thrombosis may produce a rapidly progressive loss of vision, with hemorrhages in the retina, but would not be associated with the transient attacks of amaurosis fugax. Although both posterior and middle cerebral artery ischemia can cause visual loss, they would not be expected to cause the monocular blindness of amaurosis fugax. Posterior ciliary artery ischemia can cause ischemic optic neuropathy, but this is usually acute, painless, and not associated with preceding transient monocular blindness or TIAs.
65. The answer is c. (Ropper, pp 783, 788, 789.) Based on the results of the North American Symptomatic Carotid Endarterectomy Trial (NASCET), it is known that carotid endarterectomy can reduce the risk of stroke in patients with symptomatic stenosis by 70% or more. The risk of ipsilateral stroke was reduced from 26% in the medically treated group to 9% in the surgically treated group. Carotid endarterectomy should be offered to all eligible patients with symptomatic disease of the internal carotid artery. Carotid angioplasty with stenting is an alternative for management of these patients. However, it is less established than endarterectomy. Angioplasty without stenting is not indicated. Extracranial–intracranial bypass has been tried unsuccessfully, although it may still play a role for certain patients with inaccessible lesions or hypoperfusion in the setting of complete occlusions. Aspirin would be appropriate after endarterectomy.
66. The answer is f. (Ropper, pp 466-470.) Given the patient’s history of cardiovascular disease, one must suspect that this man has sustained a stroke of the left cerebral hemisphere. Either the left internal carotid artery or the left middle cerebral artery is probably occluded. The area of infarction would be expected to include the frontal, temporal, and parietal lobe cortices. The tonic gaze deviation indicates damage to the frontal eye field on the left, which normally directs the eyes contralaterally. The right visual field loss occurs with damage to the optic radiation in the left hemisphere. Such large left hemisphere lesions are associated with a global aphasia, which is characterized by impaired comprehension, repetition, and fluency.
67. The answer is b. (Ropper, pp 466-470.) Presumably, an embolus from this woman’s heart traveled to a branch of the middle cerebral artery that supplied her dominant hemisphere. The left hemisphere is usually the speech-dominant hemisphere. Wernicke aphasia is the most common of the so-called fluent aphasias: The affected person produces a string of sounds that may sound like a real language, but the sounds are generally meaningless. The patient seems to be unaware that his or her speech is incomprehensible. Comprehension and repetition are impaired. Typically, efforts at speaking produce only a meaningless string of phonemes that retain the rhythm and intonation of normal speech.
68. The answer is g. (Ropper, pp 466-470.) According to one classic model of language organization formulated by the neurobehaviorist Norman Geschwind, the expressive language centers in the frontal lobe and the receptive centers in the temporal lobe communicate in large part along the arcuate fasciculus, which extends through the temporal and parietal lobes. This man appears to have suffered an acute hemorrhage associated with chronic hypertension. The blood extended into the lateral ventricle, which was the probable cause of the headache. Patients with the rare syndrome of conduction aphasia have problems with repetition that are more obvious than their problems with comprehension. Their speech usually does not sound very fluent.
69. The answer is a. (Ropper, pp 466-470.) Cerebrovascular occlusions are unusual at the age of 24, but this woman had two risk factors for stroke: her migraine headaches and her pregnancy. The stroke probably involved the frontal lobe cortex about the third frontal convolution on the dominant side. Speech becomes telegraphic (ie, consisting of short phrases with omission of small connecting words such as articles and conjunctions) with a Broca aphasia, but permanent loss of all ability to produce meaningful language is unlikely if the area of infarction is less than a few centimeters across. The most persistent difficulty usually exhibited by patients with this type of stroke is a permanent loss of syntax.
70. The answer is h. (Ropper, pp 466-470.) With protracted hypotension, this patient suffered a watershed infarction. The cortex at the limits of the supply of the principal cerebral arteries was inadequately perfused, and the resulting infarction isolated the speech areas in the frontal and temporal lobes from the cortex in other parts of the cerebrum. Language usually does not recover substantially after this type of infarction.
71. The answer is a. (Ropper, pp 466-470.) Broca is the classic anterior (nonfluent) aphasia and is characterized as described in the question. It is most often associated with a lesion of the left inferior frontal gyrus.
72. The answer is e. (Ropper, pp 466-470.) Anomic aphasia consists of an isolated word-finding deficit. It is the least localizable of the major aphasias. It is common in patients with diffuse brain dysfunction.
73. The answer is d. (Ropper, pp 466-470.) Transcortical motor aphasia is similar to Broca aphasia with the exception of preserved repetition. Anatomically, the lesion generally occupies left frontal white matter and spares the overlying cortex.
74. The answer is c. (Ropper, pp 466-470.) Transcortical sensory aphasia is similar to Wernicke aphasia with the exception of preserved repetition. Anatomically, the lesion generally occupies the white matter underlying the cortex of Wernicke area. In most cases, the prognosis for improvement is better than that for Wernicke aphasia.