- Which of the following should be done next?
a. Administer tissue plasminogen activator
b. Call a vascular surgery consult for possible endarterectomy
c. Order a brain CT
d. Order a cerebral angiogram
e. Start heparin
The answer is c. (Shuaib, p 58.) 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 you had 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 MRIThe answer is c. (Shuaib, p 58.) 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 you had 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
46. The patient has an MRI that is consistent with an acute stroke. The most common cause of stroke is a. Atherosclerosis b. Fibromuscular dysplasia c. Mitral valve prolapse d. Arterial dissection e. Meningovascular inflammation
- The answer is a. (Victor, p 825.) 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.
- A pure motor stroke is most likely with damage to the
a. Internal capsule
b. Cerebellum
c. Putamen
d. Caudate
e. Amygdala
- The answer is a. (Victor, p 831.) 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.
- A pure sensory stroke is most likely with damage to the
a. Internal capsule
b. Thalamus
c. Hippocampus
d. Globus pallidus
e. Pons
- The answer is b. (Victor, p 839.) 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.
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.
49. 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
- The answer is c. (Victor, pp 844–846.) Wallenberg, or lateral
medullary, syndrome is due to 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.
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.
50. The dysphagia in this case is secondary to involvement of which of the following structures? a. Nucleus solitarius b. Nucleus and descending tract of CN V5 c. Nucleus ambiguus d. Lateral spinothalamic tract e. Inferior cerebellar peduncle
- The answer is c. (Victor, pp 844–845.) 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.
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.
- Occlusion of which of the following arteries typically produces this
syndrome?
a. Basilar artery
b. Vertebral artery
c. Superior cerebellar artery
d. Anterior inferior cerebellar artery (AICA)
e. Anterior spinal artery
- The answer is b. (Victor, pp 842–846.) Most cases of lateral medullary
infarction are due to occlusion of the vertebral artery. Several small
branches of the distal vertebral artery supply the lateral medulla. In some
cases, occlusion of the posterior inferior cerebellar artery (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.
- 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. Computed tomography (CT) scan shows a right occipital
lobe hemorrhage with some subarachnoid extension of the blood. An
MRI scan with gradient echo sequences reveals foci of hemosiderin in the
right temporal and left frontal cortex. The likely cause of this patient’s symptoms
and signs is
a. Gliomatosis cerebri
b. Multi-infarct dementia
c. Mycotic aneurysm
d. Amyloid angiopathy
e. Undiagnosed hypertension
- The answer is d. (Osborn, pp 192–194.) Cerebral amyloid angiopathy
(CAA), 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’s disease) in brain
blood vessels leads to disruption of the vessel walls, which predisposes
them to hemorrhage. Patients are usually over age 70 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.
A 22-year-old male abuser of intravenous heroin complains of severe
headache while having sexual intercourse. Within a few minutes of that
complaint, 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 lesion of 3 to 4 cm
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.
53. The diagnostic study most likely to establish the basis for this patient’s neurologic deficits is a. HIV antibody testing b. Cerebrospinal fluid (CSF) examination c. Electroencephalography d. Nerve conduction studies e. Cardiac catheterization
- The answer is b. (Victor, pp 902–903.) This young man almost certainly
has numerous problems associated with his intravenous drug abuse,
but the cause of his current complaints 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. Electroencephalography would undoubtedly reveal an
asymmetric pattern associated with the left hemispheric lesion, but this too
would provide little insight into the cause of the problem. Nerve conduction studies would not clarify the basis for a lesion of the central nervous
system, because they only examine structures of the peripheral nervous
system. Cardiac catheterization might reveal valvular abnormalities, but
these need not be associated with disease of the central nervous system.
A 22-year-old male abuser of intravenous heroin complains of severe
headache while having sexual intercourse. Within a few minutes of that
complaint, 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 lesion of 3 to 4 cm
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.
- The patient’s HIV antigen test is positive, but he has no depression of his
CD4+ (helper) T lymphocyte count. Nerve conduction studies reveal generalized
slowing in the legs, and EEG exhibits depressed voltage over the left parietal
lobe. Cardiac catheterization suggests aortic valve disease, and his CSF is
xanthochromic (yellow). The probable site of injury in the CNS is
a. An arterial wall
b. The ventricular endothelium
c. The pia arachnoid
d. The dura mater
e. The perivenular space
- The answer is a. (Victor, pp 902–903.) 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
A 22-year-old male abuser of intravenous heroin complains of severe
headache while having sexual intercourse. Within a few minutes of that
complaint, 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 lesion of 3 to 4 cm
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.
- Within 1 day of admission, the patient’s right-sided weakness began to
abate, and within 1 week it completely resolved. On the fourth 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 min, but he had residual right-sided weakness
for 24 h. CT scan was unchanged from that obtained on admission.
The most appropriate treatment to institute involves
a. Heparin
b. Recombinant tissue plasminogen activator (r-TPA)
c. Lamotrigine
d. Phenytoin
e. Warfarin
- The answer is d. (Victor, pp 356–360.) 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
phenytoin (Dilantin). 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.
A 22-year-old male abuser of intravenous heroin complains of severe
headache while having sexual intercourse. Within a few minutes of that
complaint, 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 lesion of 3 to 4 cm
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.
- The focal weakness lasting for 24 h was most likely attributable to
a. Intracerebral hemorrhage
b. Subarachnoid hemorrhage
c. Encephalitis
d. Todd’s paralysis
e. Hyponatremia
- The answer is d. (Victor, pp 345–346.) That the patient had weakness
after the seizure activity is evidence of a postictal paralysis, or Todd’s paralysis. Postictal weakness does not suggest extension of the 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 due to some
kind of neuronal exhaustion occurring after frequent repetitive discharges.
It may reflect depletion of glucose in the neurons in the epileptic focus.
- A 16-year-old girl with complex partial seizures and mild mental retardation
has an area of deep red discoloration (port-wine nevus) extending
over her forehead and left upper eyelid. A CT scan of her brain would be
likely to reveal
a. A hemangioblastoma
b. A Charcot-Bouchard aneurysm
c. An arteriovenous malformation
d. A leptomeningeal angioma
e. A fusiform aneurysm
- The answer is d. (Greenberg, 2/e, p 601. Victor, pp 1077–1078.) 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 CN
#6, 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 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.
- A 72-year-old woman 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 the
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
- The answer is a. (Victor, pp 834–835.) 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 speech disorder likely
with an injury of the left frontal lobe is a Broca’s aphasia. Comprehension
would be expected to be largely intact, but if the patient has damage to
enough of the temporal lobe cortex, a Wernicke’s 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.
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 complains of 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.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 complains of 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
a. An arteriovenous malformation
b. An occipital astrocytoma
c. A sphenoidal meningioma
d. A pituitary adenoma
e. A saccular aneurysm
- The answer is e. (Victor, pp 890–892.) The clinical picture suggests
that a saccular aneurysm has become symptomatic by compressing structures
about the base of the brain and subsequently leaking. 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
forties and fifties, 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 will reveal relatively
large aneurysms if the system is calibrated and programmed to look at
blood vessels. 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.
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 complains of 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.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 complains of 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.
60. The cranial nerve injury likely to be responsible for all of these observations is one involving a. The second cranial nerve b. The third cranial nerve c. The fourth cranial nerve d. The sixth cranial nerve e. None of the above
- The answer is b. (Victor, p 285.) The red glass test produces two
images because the eyes are not moving in concert. That the red image
appears to the left indicates that the eye covered by the red glass is not
moving to the left as much as the other eye. A convenient way to remember
this is simply to assume that the eye is not moving where the red image
appears to be. This assumes that the red glass is over the impaired eye and
that ocular motor function in the other eye is completely normal. That the patient has pain behind the right eye and that the pupil of this eye reacts
less vigorously to light than the pupil of the other eye suggests that the
right eye is solely (or at least disproportionately) involved. Since the medial
rectus and pupillary constrictor are involved, the lesioned nerve must be
CN #3.
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 complains of 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.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 complains of 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
61. The site of the lesion responsible for this woman’s symptoms and signs is most probably the a. Anterior communicating artery b. Posterior communicating artery c. Anterior cerebral artery d. Middle cerebral artery e. Posterior cerebral artery
- The answer is b. (Victor, pp 888–892.) 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 cranial nerve, 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 upon the third-nerve fibers that supply the medial rectus muscle,
weakness of which was responsible for this woman’s 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, is performed in the
evaluation for subarachnoid hemorrhage and third-nerve palsy.
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 complains of 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.
- Three days after developing neck stiffness and photophobia, the woman
develops 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 and so would treat her with
a. Heparin
b. Warfarin
c. Nimodipine
d. Phenytoin
e. Carbamazepine
- The answer is c. (Victor, pp 894–895.) 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.
A 73-year-old man with a history of hypertension complains of a 10-min
episode of left-sided weakness and slurred speech. On further questioning,
he relates three brief episodes in the last month of sudden impairment of
vision affecting the right eye. His examination now is normal.
63. Which of the following would be 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
- The answer is d. (Osborn, pp 332–335.) 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 red blood cells—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
A 73-year-old man with a history of hypertension complains of a 10-min
episode of left-sided weakness and slurred speech. On further questioning,
he relates three brief episodes in the last month of sudden impairment of
vision affecting the right eye. His examination now is normal.
63. Which of the following would be 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
- The answer is d. (Osborn, pp 332–335.) 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 red blood cells—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
A 73-year-old man with a history of hypertension complains of a 10-min
episode of left-sided weakness and slurred speech. On further questioning,
he relates three brief episodes in the last month of sudden impairment of
vision affecting the right eye. His examination now is normal.
- The episodes of visual loss are most likely related to
a. Retinal vein thrombosis
b. Central retinal artery ischemia
c. Posterior cerebral artery ischemia
d. Middle cerebral artery ischemia
e. Posterior ciliary artery ischemia
- The answer is b. (Victor, pp 254–256.) 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
ischemic attacks (TIAs) described here. Although both posterior and middle
cerebral artery ischemia can cause visual loss, they would not be expected
to cause the monocular blindness described here. 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. - The answer is c. (Shuaib,
A 73-year-old man with a history of hypertension complains of a 10-min
episode of left-sided weakness and slurred speech. On further questioning,
he relates three brief episodes in the last month of sudden impairment of
vision affecting the right eye. His examination now is normal.
- A thorough evaluation reveals that the patient has a 90% stenosis of
the right internal carotid artery at the bifurcation. The management option
most likely to prevent a future stroke is which of the following?
a. Warfarin
b. Carotid artery angioplasty
c. Carotid endarterectomy
d. Extracranial-intracranial bypass
e. Aspirin
- The answer is c. (Shuaib, pp 503–506.) 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. There is
currently no randomized, controlled trial data to support the use of warfarin,
carotid angioplasty, or stenting in the management of these patients,
although studies of angioplasty are under way. Extracranial-intracranial by pass 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.
- 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. (SELECT 1
DISTURBANCE)
For each clinical scenario, pick the language disturbance that best explains
the clinical picture.
a. Broca’s aphasia
b. Wernicke’s aphasia
c. Transcortical sensory aphasia
d. Transcortical motor aphasia
e. Anomic aphasia
f. Global aphasia
g. Conduction aphasia
h. Mixed transcortical aphasia
- The answer is f. (Victor, pp 504–515.) Given the patient’s history of
cardiovascular disease, one must suspect that this man has suffered 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 lobe center
on the left, which directs the eyes contralaterally. The right visual field loss
occurs with damage to the optic radiation in the left hemisphere
- 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. (SELECT 1 DISTURBANCE
For each clinical scenario, pick the language disturbance that best explains the clinical picture. a. Broca’s aphasia b. Wernicke’s aphasia c. Transcortical sensory aphasia d. Transcortical motor aphasia e. Anomic aphasia f. Global aphasia g. Conduction aphasia h. Mixed transcortical aphasia
- The answer is b. (Victor, pp 504–515.) 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’s 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 only produce a meaningless string of phonemes that
retain the rhythm and intonation of normal speech.
-
headache and fascial pain17
-
epilepsy and seizures22
-
neoplasm26
-
eye disease40
-
Infections45
-
Disorder of Myelination20
-
CerebroVascularDisease27
-
The Neurological Examination and Diagnostic Test45
-
traumatic and occupational injuries15
-
NEUROMUSCULAR DISORDERS20
-
Spinal Cord and Root Disease26
-
Nutritional and Metabolic Disorders30
-
Dementia and Cognitive Disorders20
-
Movement Disorders25
-
Disturbance of hearing balance and test20
-
Developmental and hereditary disorders40
-
Toxic Injury15
