Vascular Flashcards
Following a renal transplant, a 38-year-old woman on cyclosporine and prednisone develops
hypertension, encephalopathy, and seizures. Which of the following is the most likely cause of her
clinical syndrome?
A. Drug toxicity
B. Posterior reversible encephalopathy syndrome
C. Viral encephalitis
D. Subarachnoid haemorrhage
E. Reversible cerebral vasoconstrictor syndrome
Posterior reversible encephalopathy syndrome
Posterior reversible encephalopathy syndrome (PRES) is an acute condition which presents with
headache, confusion and seizures. Whilst the same is true for Subarachnoid hemorrhage,
Reversible Cerebral Vasoconstriction Syndrome (RCVS) and viral encephalitis, in this case the
history of renal transplant and immunosuppressants make PRES the more likely diagnosis. The exact pathophysiology of PRES is not known but includes a loss of cerebral autoregulation and hyperperfusion with break down of the blood brain barrier and cerebral odema. Imaging will demonstrate parietal and occpital lobe vasogenic oedema. Treatment is supportive, correcting the underying cause with many patients requiring admission to intensive care.
Sacral sparing of pain and temperature sensation is seen most often with which of the following
spinal cord syndromes?
A. Brown-Séquard syndrome
B. cauda equina syndrome
C. Central cord syndrome
D. anterior cord syndrome
E. posterior cord syndrome
Central cord syndrome
Sacral sparing of pain and temperature sensation is most often seen with central cord syndrome,
which typically effects upper extremities more than lower extremities. Brown-Séquard syndrome results in contralateral loss of pain and temperature sensation below the level of the lesion.
Anterior cord syndrome causes loss of pain and temperature at and below the level of injury.
Posterior cord syndrome is characterized by isolated loss of proprioception and vibratory
sensation. Cauda equina syndrome presents with perianal and saddle paresthesia with bowel,
bladder and/or sexual dysfunction.
Intravenous tissue plasminogen activator should be administered within a maximum of how many hours after a patient sustains an acute ischemic stroke?
A. 1.5
B. 3
C. 4.5
D. 6
E. 24
4.5
Both the American Stroke Association and European Stroke Association guidelines recommend administering IV alteplase within 4.5 hours of symptom onset. This includes wake-up strokes where the patient was last seen well <4.5hours ago. The 2014 meta-analysis by Emberson (cited in the ESO guidelines) contains 9 RCTs with 6700 patients and demonstrates a improved rate of mRS 0-1 outcomes at 3 months for all age groups and stroke severity up to 4.5 hours after symptom onset, however the groups receiving IV alteplase >4.5hr after symptom onset did not show a statistically significant benefit. A meta-analysis by Campbell of the EXTEND, EPITHET and ECASS4 trials did not show a benefit of alteplase after 4.5 hours when the wake up strokes were removed from analysis
Injury to the fornix can cause
A. poikilothermia
B. hemiplegia
C. anterograde amnesia
D. alexia
E. apraxia
anterograde amnesia
Isolated damage to the fornix has been reported to cause anterograde amnesia. Poikilothermia is
loss of normal thermoregulation that can result from hypothalamic injury. Hemiplegia is complete paralaysis of half of the body. It can be caused by a wide variety of medical conditions including brain and spinal cord injury. Alexia is a disorder of reading that is seen with injury of the dominant angular gyrus. Apraxia is a disorder of motor planning to perform tasks or movements. It is seen with posterior paretal cortex and corpus callosum injuries
Which of the following Fisher grades has the highest predictability of vasospasm when evaluating patients with a subarachnoid hemorrhage?
Answers:
A. Grade 0
B. Grade 1
C. Grade 2
D. Grade 4
E. Grade 3
Grade 3
Thick cisternal clot increases the risk of vasospasm. In the original Fisher scale, grade 3, thick cisternal clot, has the highest risk of vasospasm but in the modified scale, grade 4, thick cisternal clot with Intraventricular Hemorrhage (IVH), has the highest risk of vasospasm. In the original Fisher scale, no SAH nor IVH is grade 1 while diffuse thin SAH is grade 2 without clots, and grade 3 is locaized clots iand or layers of blood greater than one mm in thickness. IVH and ICH is grade 4. In the modified Fisher scale, focal or diffuse thin subarachnoid hemorrhage (SAH) with no IVH is grade 1, while focal or diffuse thin SAH with IVH is grade 2. Focal or diffuse thick SAH without IVH is grade 3 and focal or diffuse thick SAH with IVH is grade 4. No SAH seen on CT head is grade 0.
Which of the following types of aphasia is characterized by severely affected ability to repeat
words, relatively normal comprehension, awareness of the speech deficit, and fluent paraphasic
speech?
Answers:
A. anomic aphasia
B. expressive aphasia
C. transcortical sensory aphasia
D. global aphasia
E. conduction aphasia
conduction aphasia
Conduction aphasia is characterized by pronounced difficulty with repetion with intact comprehension and fluency in spontaneous speech. The lesion is located at the arcuate fasciculus. Patients with anomic aphasia have mild expressive language deficits in word finding especially specific nouns and verbs. Expressive (Broca’s) aphasia may result from injury to the dominant inferior frontal gyrus. Individuals with expressive aphasia have trouble speaking fluently but comprehension is relatively preserved. Transcortical sensory aphasia is an uncommon form of aphasia that may occur when a lesion functionally isolates Wernicke’s areas from the rest of the brain. This results in intact repetition and articulation, but compromised speech comprehension. Global aphasia is a severe form of nonfluent aphasia, caused by damage to the dominant hemisphere. Both receptive and expressive language skills as well as auditory and visual comprehension are compromised.
Which of the following is the most likely cause of an intracranial large vessel occlusion in a patient
with cryptogenic stroke?
Answers:
A. mitral stenosis
B. paroxysmal atrial fibrillation
C. thrombophilia
D. Arterial dissection
E. Atherosclerosis
paroxysmal atrial fibrillation
Paroxysmal atrial fibrillation is one of the most common underlying causes of cryptogenic stroke and large vessel occlusion. Cryptogenic stroke has been reported as an independent marker of paroxysmal atrial fibrillation. Antiplatelet therapy is the mainstay of treatment. The Trial of Org 10172 in Acute Stroke Treatment defines Acute Stroke Treatment defines cryptogenic stroke (CS) as a cerebral infarct not attributed to a definite source of cardioembolism, large-vessel atherosclerosis, or small-vessel disease, despite (1) extensive cardiac, vascular, hematologic, and serological evaluation; (2) evidence of >1 competing cause, or (3) incomplete diagnostic evaluation. The Causative Classification System definition requires a diagnostic evaluation, including brain and cerebrovascular imaging along with a cardiac evaluation. Causative Classification System divides cryptogenic stroke into 2 categories: cryptogenic embolism and other cryptogenic. Cryptogenic embolism refers to a stroke in which there is angiographic evidence of abrupt cutoff consistent with a blood clot within otherwise angiographically normal-looking intracranial arteries, imaging evidence of complete recanalization of previously occluded artery, or the presence of multiple acute infarctions that have occurred closely related in time without detectable abnormality in the relevant vessels. Other cryptogenic is reserved for those not fulfilling the criteria of cryptogenic embolism.
A 48-year-old man is evaluated because of dizziness, vertigo, and hoarseness after having
chiropractic neck manipulation. Examination shows nystagmus, paralysis of the right palate,
decreased sensation to pinprick on the right side of the face and left hemibody, and right-sided
ataxia. This patient most likely has a lesion in which of the following locations?
Answers:
A. Posterior Inferior Cerebellar Artery
B. Vertebral artery
C. Anterior spinal artery
D. Superior Cerebellar Artery
E. Basilar artery
Vertebral artery
The patient has lateral medullary syndrome which is most commonly due to occlusion of the Posterior Inferior Cerebellar Artery artery, followed by the vertebral artery. However arterial pathology following chiropractic neck manipulation is most likely vertebral artery dissection which makes this the best answer to this question. Lateral medullary syndrome (Wallenberg syndrome) is comprised of vertigo with nystagmus (due to inferior vestibular nucleus and pathways), ipsilateral Horner’s (due to sympathetic fibers), contralateral pain/temperature loss (due to spinothalamic tract), and dysphonia/dysphagia/dysarthria (due to different nuclei and fibers of the IX and X nerves). Sensory loss is the most common feature (90%) which can be a combination of hemibody and/or trigeminal distributions. The other symptoms are all found in 70-75% of cases.
Which of the following is clopidogrel bisulfate’s mechanism of action in stroke prevention?
Answers:
A. GPIIb/IIIa inhibitor
B. COX inhibitor
C. P2Y12 ADP antagonist
D. ATP analogue
E. PAR-1 antagonist
P2Y12 ADP antagonist
All answers are methods of platelet inhibition. The incorrect answers are: GPIIb/IIIa inhibitors (abciximab), COX inhibitors (aspirin), ATP analogues (cangrelor), and PAR-1 antagonists (vorapaxar). Clopiogrel is an irreversible, competitive P2Y12 ADP receptor antagonist. Initial platelet activation occurs through interaction of the platelet with the exposed subendothelium. Upon platelet activation ADP is released from platelet dense granules which creates a cascade of subsequent activation and recruitment to the platelet plug.
In a patient who has sustained an aneurysmal subarachnoid hemorrhage, what is the peak time for
development of symptomatic vasospasm?
Answers:
A. 1-3 days
B. 4-6 days
C. 7-10 days
D. 11-14 days
E. 15-18 day
7-10 days
The risk of vasospasm peaks at day 7-10. The risk of vasospasm is low on 1-3, then increases, reaching its peak from day 7-10. After day 10 the risk of vasospasm starts decreasing again. It is rare after day 14.
The Mini Mental State Examination (MMSE) tests the functionality of the right hemisphere by
which of the following methods?
Answers:
A. serial 7’s
B. orientation questions
C. copying a symbol
D. recall of objects
E. repeating the given sentence
copying a symbol
Copying symbols is a measure of constructional ability which is a function of the non-dominant parietal lobe. Serial 7s, orientation questions, object recall, and phrase repetition are all tests of the dominant hemisphere.
A 12-year-old boy is evaluated because of sudden severe headache, neck stiffness, and vomiting.
A CT scan of the head shows diffuse subarachnoid hemorrhage. Which of the following is the most
likely cause of these findings?
Answers:
A. ICA aneurysm
B. Vertebrobasilar dissecting aneurysm
C. ACA aneurysm
D. AVM
E. MCA aneurysm
ICA aneurysm
The correct answer is ICA aneurysm. Although most of our data regarding pediatric aneurysms comes from smaller retrospective series as these are so rare, there is general consensus that the locations for pediatric aneurysms differ from those seen in adults. The most comm site for a ruptured aneurysm in an adult is ACOM, followed by PCOM. In children, the most common site is the intracranial ICA, and in particular the ICA bifurcation. The incidence of ICA terminus aneurysms is estimated to be 5x higher in pediatric than in adult ruptured aneurysms. There is a higher incidence of giant aneurysms in the pediatric population, but these still account for a minority (10-20%) of cases in the literature. MCA aneurysm is incorrect. In the pediatric population, MCA aneurysms are approximately as commonly reported as ACA aneurysms and less common than ICA and vertebrobasilar aneurysms. There is some evidence that MCA aneurysms may be more commonly seen in children <1 year of age. AVM is incorrect. The most common cause of non-traumatic ICH in children is AVM. However, the question asks about diffuse SAH and ruptured AVM is not typically associated with SAH. Rupture of AVM-associated (feeding vessel or pre-nidal) aneurysms may result in SAH or pure IVH, in the case of a distal anterior choroidal or posterior medial choroidal artery feeding aneurysm, and so careful examination of non-invasive and angiographic images in cases of ruptured pediatric AVM is critical to identify the cases in which bleeding from the nidus is not the immediate cause of intracranial hemorrhage, be it intra-parenchymal, subarachnoid or intraventricular. ACA aneurysm is incorrect. In adults, ACOM aneurysms account for the highest single location of ruptured aneurysms. Distal ACA aneurysms are less common, and less commonly associated with rupture due to smaller vessel size and lower flow. They are a common location for mycotic aneurysms, however. In the pediatric population, ACA aneurysms are approximately as commonly reported as MCA aneurysms and less common than ICA and vertebrobasilar aneurysms. Overall, Acom aneurysms are thought to be the third most common location for pediatric ruptured aneurysms, occurring in about 12% of cases. Vertebrobasilar dissecting aneurysm is incorrect. Posterior circulation aneurysms are more common in children than in adults but are still less common than supraclinoid ICA aneurysms. There is a higher incidence of fusiform aneurysms in the pediatric population, but dissection is less likely to be a cause in this case due to the absence of trauma in the history. Spontaneous dissection causing aneurysmal dilatation or pseudoaneurysm in the pediatric population is rare, unless there is a concurrent history of a connective tissue disorder such as Ehlers-Danlos syndrome Type 4 or Marfan syndrome.
An increased risk for rupture of an asymptomatic intracranial aneurysm is most commonly
associated with which of the following disorders?
Answers:
A. Ehler-Danlos Type 4
B. Marfan syndrome
C. Pseudoxanthoma elasticum
D. Autosomal dominant polycystic kidney disease
E. Autosomal recessive polycystic kidney disease
Autosomal dominant polycystic kidney disease
The correct answer is autosomal dominant polycystic kidney disease (ADPKD). Autosomal recessive polycystic kidney disease is not associated with aneurysm formation. The other three options are all connective tissue disorders with an increased risk of aneurysm formation however are less common than ADPKD (1:2000). Amongst patients with ADPKD, 10% will have unruptured incidental aneurysm compared to 3% of the general population. The rupture risk is also x4 compared to standard unruptured incidental aneurysm.
Which of the following types of aphasia is characterized by preserved repetition?
Answers:
A. expressive aphasia
B. global aphasia
C. conduction aphasia
D. transcortical motor aphasia
E. receptive aphasia
transcortical motor aphasia
Transcortical motor aphasia resembles expressive aphasia but patients are able to repeat. The
other aphasia syndromes listed demonstrate impaired repetition.
The most reliable method of differentiating CSF rhinorrhea from other forms of rhinorrhea is
Answers:
A. target test
B. glucose oxidized test
C. chlorine concentration
D. beta-2 transferrin
E. glucose concentration
beta-2 transferrin
Beta-2 transferrin is only found in CSF, perilymph, and vitreous humor and is thus a marker with extremely high sensitivity and specificity. The target sign also called a double ring sign or a Halo sign is tested for by applying the fluid sample to filter paper. When positive, the target sign suggests that CSF is mixed with blood or nasal discharge as CSF moves away on the filter paper and blood moves closer, such that two rings are visible. The CSF glucose level from nasal or ear secretions can be used to test for CSF leak. Glucose oxidase strips show positive results when the sample has a concentration of glucose over 20 mg/dL. Nasal discharge has a normal concentration of 10 mg/dL of glucose, thus, if the glucose test is negative the presence of CSF can be ruled out. However, there is a high false positive rate since hyperglycemia, epithelial inflammation, and bacterial infection may confound the result. Identification of glucose in combination with chlorine concentration of 100 mEq/L in nasal secretion has also been reported for the identification of CSF.
Which of the following racial groups has the highest prevalence of intracranial atherosclerotic
disease?
A. caucasian
B. native american
C. african american
D. asian
E. no difference between racial grouops
african american
Intracranial atherosclerosis is considered to be more frequent in African American when compared to other racial groups. In the United States, it disproportionately affects African American, Latin Americans, and Asian Americans, and it is associated with multiple modifiable risk factors including smoking, hypertension, hyperlipidemia, and diabetes.
A healthy right-hand dominant 17-year-old boy has a generalized tonic-clonic seizure. MR image
of the brain shows an arteriovenous malformation of the left posterior superior temporal gyrus that
is 2.5 cm in diameter and has venous drainage into the basal vein of Rosenthal. Which of the
following is the most likely Spetzler-Martin grade?
Answers:
A. Grade 1
B. Grade 2
C. Grade 3
D. Grade 4
E. Grade 5
Grade 3
This patient receives 1 point for eloquent cortex, 1 point for deep venous drainage, and considering that the size of the AVM is less than 3 cm, the patient receives another 1 point. All together this patient has grade 3 AVM on the Spetzler-Martin grading system. If the venous drainage is superficial only, patient receives 0 points and if the area involved is non-eloquent, then the patient receives 0 points. Patients receive 2 points for AVM sizes between 3-6cm, and those with AVM sizes more than 6 cm receive 3 points. Spetzler-Martin grading system predicts the risk associated with surgical resection of the AVM, and the higher the grade the more the surgical risks.
Which of the following is the most appropriate first-line treatment for symptomatic intracranial
atherosclerotic disease?
Answers:
A. observation with tight blood pressure control
B. anticoagulation
C. Surgical intervention
D. endovascular treatment
E. antiplatelet medication
antiplatelet medication
Stict control of atherosclerotic risk factors and medical management with antithrombotic therapy preferably with antiplatelet medications is the first-line treatment of patients with symptomatic intracranial atherosclerotic disease. Open revascularization and endovascular therapy with balloon
angioplasty and stenting should be considered in elegible patients with failure of medical therapy.
A 24-year-old woman experiences pain in the anterior aspect of the neck after vigorous exercise.
Examination shows ptosis, miosis, and contralateral paresis. Which of the following is the most
appropriate diagnostic study?
Answers:
A. Diagnostic cerebral angiogram
B. CT angiography
C. MRI angiography
D. MRI
E. Carotid ultrasound
CT angiography
This young patient with sudden onset ptosis and miosis likely has carotid artery dissection due to trauma to the artery with vigorous exercise. This would cause anterior neck pain. Hemiparesis could be related to thromboembolic phenomenon or decreased perfusion. In an emergent setting CT/ CTA is the best modality for initial evaluation. CT angiogram (CTA) can be quickly obtained with a head CT to look for hemorrhage and stroke, and it is less invasive than cerebral angiography. MRI/ MRA are less sensitive for carotid dissection and more time consuming with limited availability at many hospitals. Diagnostic cerebral angiogram is an invasive test and more time consuming than CT/CTA and is generally not needed for the diagnosis of carotid dissection. Carotid ultrasound is also a less sensitive modality than CTA for carotid dissection.
A 55-year-old man with paroxysmal atrial fibrillation is brought to the emergency department two
hours after the acute onset of left facial droop, hemiparesis, and slurred speech. The patient is on
aspirin therapy. CT scans of the head are shown. Which of the following is the most appropriate
initial step in management?
Answers:
A. intravenous thrombolysis alone
B. intraarterial thrombolysis alone
C. endovascular intervention alone
D. medical management
E. intravenous thrombolysis followed by endovascular intervention
intravenous thrombolysis followed by endovascular intervention
Intravenous thrombolysis is recommended in eligible patients presenting within 4.5 hours of symptom onset. Mechanical thrombectomy is recommended in patients with large vessel occlusion within 6 hours of presentation, and may be considered in selected patients up to 16 to 24 hours of last known normal. Atrial fibrillation is a frequent cause of stroke and medical management should entail anticoagulation for patients with a CHAD2 score of >2. Aspirin is not considered effective for stroke prevention in patients with atrial fibrillation.
For each condition, select the most likely associated finding (A-E).
Tolosa-Hunt syndrome
Answers:
A. Trigeminal nerve palsy
B. Facial nerve palsy
C. Pupillary dilation
D. Optic nerve atrophy
E. Ocular motor nerve palsy
Ocular motor nerve palsy
According to the International Headache Society (IHS) 3rd guidelines Tolosa-Hunt syndrome is a clinical combination of unilateral periorbital pain with cranial nerve 3, 4 or 6 palsy. Cranial nerve palsy occurs within 2 weeks of headache onset. The causes of this sydrome classically include aneurysm, trauma, tumour, or inflammation affecting the cavernous sinus however the IHS guidelines specifically refer to a granulomatous cause. Optic, trigeminal, facial or parasymapthetic nerves can also be involved but are not required to meet the diagnostic criteria.
A 35-year-old woman comes to the emergency department because of new onset left hemiparesis.
Past medical history is significant for three miscarriages and a deep venous thrombosis ten years
ago. CT scan of the head and MR imaging of the brain show new areas of ischemic stroke. Her
workup should include which of the following tests?
Answers:
A. heparin-PF4 antibodies
B. TSH
C. von-willebrand factor
D. anticardiolipin antibodies
E. factor X deficiency
anticardiolipin antibodies
Antiphospholipid syndrome is an autoimmune, hypercoagulable state caused by antiphospholipid antibodies that can be primary or secondary to other autoimmune diseases such as Systemic Lupus Erythematosus. Diagnostic criteria include a clinical event related to thrombosis or pregnancy complications and two positive blood test results for lupus anticoagulant, antiapolipoprotein antibodies, or anti-cardiolipin antibodies. Treatment consists of anticoagulation therapy to prevent further thrombotic events.
The cranial nerve most commonly involved in CNS sarcoidosis is the
Answers:
A. CN III
B. CN IV
C. CN V
D. CN VI
E. CN VII
CN VII
The facial nerve is most commonly involved with CNS sarcoidosis and is seen in 25-50% of cranial neuropathy cases associated with CNS sarcoidosis. Cranial neuropathy of neurosarcoidosis can involve one or multiple cranial nerves simultaneously. CN III, IV, V, and VI neuropathies are rarely seen with CNS sarcoidosis.
A 24-year-old woman is referred for evaluation because of recurrent seizures refractory to medical therapy. MR images are shown. Which of the following is the most likely nonhemorrhagic postoperative complication following microsurgical resection of this lesion?
Answers:
A. Wound infection
B. Permanent mutism
C. Temporary akinesia
D. Deep vein thrombosis
E. Right leg weakness
Temporary akinesia
The correct answer is temporary akinesia. Resection of this lesion, which is located in the left superior frontal gyrus, is often associated with supplementary motor area syndrome, the clinical sequelae of which include global akinesia on the contralateral side, with preserved muscle strength and mutism. This syndrome typically completely resolve within weeks to months – although the timeline is variable, a full recovery is typically observed within about 3 months. The incidence of SMA syndrome after dorsomedial prefrontal lobe surgery ranges widely in the literature but has been reported at anywhere from 25% to near 100%. The higher the proportion of the anatomical SMA that is resected, the higher chance of observing the clinical syndrome. Permanent mutism is not a correct answer. Mutism is associated with SMA syndrome, but the condition is temporary and spontaneous speech tends to recover suddenly, but patients may have difficulties with speech fluency problems for a longer period of time. A full recovery can be expected in most cases. Wound infection is not the correct answer. The expected incidence of infection after craniotomy for brain tumors is 2-4%. Deep vein thrombosis is not the correct answer. The incidence of DVT after craniotomy for brain tumor in national database analyses is approximately 2.5%. Right leg weakness could be related to a right ACA infarction and is not the correct answer. The incidence of symptomatic ischemic stroke has been reported to occur in approximately 15% of patients undergoing resection of low grade gliomas, most commonly among patients undergoing recurrent surgery or with insular lesions.
A right-handed 55-year-old man has agraphia, alexia, acalculia, finger agnosia, right-left
disorientation, and difficulty spelling. Which of the following areas of the brain is the most likely site
of a lesion?
Answers:
A. Insula
B. Left pars triangularis
C. Calcarine Sulcus
D. Left Angular Gyrus
E. Parahippocampal Gyrus
Left Angular Gyrus
The constellation of agraphia, alexia, acalculia, finger agnosia, and right-left disorientation represents pure Gerstmann Syndrome, and typically occurs as a result from malfunction of cortex in the region of the dominant angular gyrus. The syndrome rarely appears in isolation. The insulae are involved in consciousness and are linked to emotion and regulation of body homeostasis. The triangular part of the dominant inferior frontal gyrus is a component of Broca’s area and is responsible for speech production. The peripheral visual field is located along the anterior portion of the calcarine sulcus and the central visual field is located in the posterior portion. The parahippocampal gyrus lies within the medial temporal lobe surrounding the hippocampus. It is important role in both spatial memory and navigation.
Which of the following findings is suggestive of a lateral medullary syndrome?
Answers:
A. decreased pain and temperature sensation from ipsilateral body
B. ipsilateral oculomotor palsy
C. contralateral parkinsonian rigidity
D. hoarseness
E. contralateral hemiparesis
hoarseness
Hoarseness is a common finding among patients with lateral medullary syndrome (Wallenberg’s syndrome) reflecting injury of the nucleus ambiguus. Additional bulbar symptoms include dysphonia, dysphagia, dysarthria, and decreased gag reflex. Loss of temperature and pain sensation typically occcurs ipsilaterally in the face and contralaterally in the body. Ipsilateral occulomotor palsy, contralateral parkinsonian rigidity, and contralateral hemiparesis are seen in Weber syndrome, a midbrain stroke syndrome involving the cerebral peduncle and ipsilateral fascicles of the oculomotor nerve.
An 80-year-old man with a history of dementia and prior intracerebral hemorrhage is found
unresponsive. A CT scan of the head is shown. Which of the following is the histopathologic
hallmark of this patient’s most likely condition?
Answers:
A. a-synuclein deposition
B. neurofibrillary tangles
C. Chronic lymphocytic inflamation
D. perivascular pseudorossettes
E. b-amyloid deposition
b-amyloid deposition
Cerebral amyloid angiopathy is a frequent cause of intracerebral hemorrhage and its characterized by its lobar distribution in elderly patients. Cerebral amyloid angiopathy is characterized by perivascular deposition of b-amyloid in small and middle sized vessels. a-synoclein is a protein commonly found in Parkinson’s disease. Neurofibrillary tangles are found in Alzheimer’s disease. Perivascular pseudorosettes are characteristic of ependymomas. Chronic lymphocytic inflamation is seen in inflammatory etiologies such as chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS).
Which of the following is a feature of the syndrome of alexia without agraphia?
Answers:
A. ideomotor apraxia
B. abulia
C. hemiplegia
D. right homonymous hemianopia
E. left homonymous hemianopia
right homonymous hemianopia
Alexia without agraphia is commonly caused by a left PCA infarct. It is often associated with right homonymous hemianopia. Ideomotor apraxia is characterized by the inability to correctly imitate hand gestures and voluntarily mime tool use. It is seen with injuries to the dominant parietal and premotor areas. Abulia is characterized by a lack of will or initiative and can be seen as a disorder of diminished motivation. It can be seen in frontal lobe injuries. Hemiplegia describes paralysis on one side of the body and can be seen in a range of injuries spanning the brain and spinal cord.
A 55-year-old woman with a history of type 2 diabetes mellitus is evaluated for a two-day history of
diplopia and ptosis of the left eye. Physical examination shows left ptosis; the left eye is deviated
down and out, and the pupil is 5 mm in diameter and unreactive. She is awake and alert, and her
neurological examination is otherwise nonfocal. Which of the following is the most likely diagnosis?
Answers:
A. Left posterior communicating artery aneurysm
B. Giant cavernous ICA aneurysm
C. Tolosa-Hunt syndrome
D. Diabetic third nerve palsy
E. Uncal herniation
Left posterior communicating artery aneurysm
A left posterior communicating artery aneurysm is the most likely of the listed causes for the patient’s symptoms, and is the correct answer. Any compressive lesion of the third nerve will cause similar symptoms. Direct compression of the nerve from the outside causes a third nerve palsy that also involves the pupil (i.e. the pupil is dilated and unreactive). The third cranial nerve has two parts: outer parasympathetic fibers that supply the ciliary muscles and sphincter; and inner somatic fibers that supply levator palpebrae superioris and extraocular muscles. The extraocular muscles supplied by the third nerve include the superior rectus, middle rectus, inferior rectus, and inferior oblique. Diabetic third nerve palsy causes ischemia of CNIII and is the most common cause of an acquired unilateral CNIII palsy. However, it is not the correct answer. Diabetic CNIII palsy is typically pupil sparing (i.e., the pupil will remain small) since the diabetic lesion is ischemic, affecting the vasa nervorum and thus sparing the pupillary fibers. Tolosa-Hunt syndrome is a rare painful ophthalmoplegia due to cavernous sinus inflammation. It is usually a clinical diagnosis of exclusion, and pain is a key feature. It typically responds to steroid treatment. Uncal herniation will cause a third nerve palsy that is similar to that caused by a PCOM aneurysm, however, this is typically caused by a compressive lesion such as an extradural hematoma, which would be associated with decreased LOC and other symptoms. A giant cavernous ICA aneurysm is not the correct answer. Although these may present with cranial neuropathies, it is more likely that multiple cranial neuropathies will be observed rather than an isolated CNIII palsy. Furthermore, the third nerve palsy will classically not produce a dilated pupil because the sympathetics that dilate the pupil are paralyzed along with the nerve itself. A sixth nerve palsy is typically the first cranial neuropathy associated with a giant ICA aneurysm.
Which of the following common cardiac pathologies is most often associated with cerebral
embolism?
Answers:
A. Atrial fibrillation
B. Congestive heart failure
C. Recent myocardial infarction
D. Mechanical prosthetic valve
E. Mitral rheumatic stenosis
Atrial fibrillation
Atrial fibrillation most frequently results in cerebral embolism followed by myocardial infarction (1.5% - 25%). Myocardial infarction (2.5%) and congestive heart failure (2%) can also result in thromboembolism, however much less commonly than atrial fibrillation. Likewise mitral rheumatic stenosis and prosthetics heart valve are other rare causes of cerebral embolism.
Which of the following findings is most likely in a patient with a hemorrhage from a cranial dural arteriovenous fistula?
Answers:
A. Venous drainage into spinal perimedullary veins
B. Cortical venous drainage with more than one draining vein
C. Cortical venous drainage with venous aneurysm
D. Venous drainage into a dural venous sinus with retrograde flow
E. Supply to the fistula from the intracranial, as well as the extracranial, circulation
Cortical venous drainage with venous aneurysm
The correct answer is cortical venous drainage with venous aneurysm. Venous aneurysm, ectasia, stricture or a pseudophlebitic pattern are all evidence of venous hypertension and predispose to hemorrhagic presentation. Cortical venous drainage, alone more so than in combination with flow into a sinus, is a high-risk feature. Another angiographic feature that predisposes dAVFs to rupture is sinus thrombosis, which can be antegrade (usually thrombosis of the draining sigmoid sinus) and/or retrograde (e.g. superior sagittal sinus thrombosis). Patients who present with aggressive symptoms including progressive neurological signs are at higher risk of developing hemorrhage. Venous drainage into a dural venous sinus with retrograde flow represent an intermediate risk dAVF. Fistulae that drain into a sinus are generally lower risk than those that have cortical venous drainage, even if there is retrograde flow in the sinus. Venous drainage into spinal perimedullary veins represents a Cognard Type 5 dAVF. This is most often associated with progressive symptoms of myelopathy related to venous congestion/venous hypertension in the medulla or cervical cord. Although it is considered a high-risk feature and would be associated with an elevated risk of hemorrhage compared with a low grade dAVF, these lesions are rare. Cortical venous drainage with more than one draining vein is rare but can occasionally be seen at surgery or at endovascular intervention. In this case, the multiple routes of venous drainage would reduce, rather than increase, the risk of hemorrhage. Supply to the fistula from the intracranial, as well as the extracranial, circulation is not in and of itself a risk factor for hemorrhage. Commonly, transverse-sigmoid sinus fistulae can parasitize arterial supply from the artery of Bernasconi & Cassinari, a branch of the meningohypophyseal trunk of the ICA. This dural branch is not usually amenable to endovascular embolization and may necessitate a transvenous approach for complete cure in these cases.
Which of the following complications is most likely to occur as a result of a difficult surgical clipping
of an unruptured right choroidal artery aneurysm?
Answers:
A. Aphasia
B. Hemianesthesia
C. Contralateral hemianopia
D. Hemiparesis
E. Hemineglect
Hemiparesis
Hemiparesis is the most common neurological deficit that can happen after inadvertently clipping of the anterior choroidal artery during surgery for anterior choroidal artery aneurysms. This is due to the infarct of the posterior limb of the internal capsule. Hemianesthesia can also happen however this often this often recovers in majority of the case after time. Infarction is less frequent in the thalamus, midbrain, temporal lobe, and lateral geniculate body territories of the AChA. Homonymous upper-quadrant anopia, hemianopia, or upper- and lower-quadrant sector anopsia can be present. A homonymous defect in the upper and lower visual fields sparing the horizontal meridian indicates a lesion in the lateral geniculate body in the territory of the AChA. Aphasia does not typically happen from AChA infarct.
A patient has the new onset of expressive aphasia six days after clipping of a ruptured middle cerebral artery aneurysm. Which of the following is the most likely cause?
Answers:
A. Subdural hematoma
B. Cerebral vasospasm
C. Thromboembolism
D. Seizure
E. Aneurysm rebleeding
Cerebral vasospasm
Six days after SAH it is unlikely for the patient to suffer from other complications as compared to vasospasm. Risk of vasospasm peaks at day 7-10. Subdural hematoma is less likely to happen in such a delayed fashion. Aneurysm rebleeding is unlikely to cause expressive aphasia without significant headache and nausea and other symptoms. Seizure is a possibility however unlikely to result in isolated expressive aphasia. Thromboembolic cause is also much less likely this far out from surgery.
In a patient with an intracranial dural arteriovenous fistula, which of the following features is most
predictive of increased risk of hemorrhage?
Answers:
A. Transverse-sigmoid sinus junction location
B. Aggressive symptoms
C. Direct cortical venous drainage
D. Age > 50 years
E. Associated aneurysms
Direct cortical venous drainage
Direct cortical venous drainage is significantly associated with an increased risk of hemorrhage from the dAVF. Aggressive symptoms at presentation are also associated with an increased risk of hemorrhage of dAVF, however this risk is less than that associated with direct cortical venous drainage. Previous hemorrhage from the dAVF poses the highest risk for subsequent rehemorrhage. Frontal dAVF and the fistulas associated with sagittal sinus are associated with increased risk of hemorrhage as compared to other locations. Carotid-cavernous fistulas have a low risk of hemorrhage due to many venous outflow channels. Age more than > 50 years is inconsistently associated with increased risk of hemorrhage. Generally dAVF are not associated with aneurysms.
A 65-year-old patient is brought to the emergency department because of a 45-minute history of
acute onset gaze deviation, aphasia, and right-sided hemiplegia. Non-contrast CT scan is negative
for intracranial hemorrhage or other acute processes. Which of the following is the most
appropriate next step in management?
Answers:
A. intravenous thrombolysis
B. intraarterial thrombolysis
C. endovascular intervention
D. medical management
E. intravenous thrombolysis followed by endovascular intervention
intravenous thrombolysis followed by endovascular intervention
According to the American Heart Association (AHA) guidelines on management of acute ischemic stroke, intravenous thrombolysis is recommended in elegible patients that present within 4.5 hours of ischemic stroke symptom onset. Endovascular intervention with mechanical thrombectomy should be performed in patients with large vessel occlusion within 6 hours of symptom onset, and may be considered in selected patients with acute ischemic stroke within 16 to 24 hours of last known normal.
Which of the following structures is indicated by the arrow in the photograph of a right pterional
craniotomy shown?
Answers:
A. Membrane of Liliequist
B. Lamina terminalis
C. Optic chiasm
D. Cerebellar tentorium
E. Opticocarotid cistern
Lamina terminalis
The lamina terminalis is a thin sheet of gray matter and pia mater stretches upward between the optic chiasm and rostrum of the corpus callosum. It forms the anterior wall of the third ventricle. Its opening allows entry into the third ventricle and release of significant amount of CSF. This facilitates aneurysm dissection without excessive brain retraction. The membrane of Liliequist is an important landmark during dissection of the interpeduncular cisterns. It is stretched between the mammillary bodies and the dorsum sellae and laterally bordered by the oculomotor nerves. The cerebellar tentorium or tentorium is an extension of the dura mater that separates the cerebellum from the inferior portion of the occipital lobes. The opticocarotid cistern is accessed between the optic nerve and the internal carotid artery.
Occlusion of which of the following arteries is the cause of the stroke in the MR image shown?
Answers:
A. anterior choroidal artery
B. recurrent artery of Heubner
C. subcallosal artery
D. pericallosal artery
E. posterior choroidal artery
subcallosal artery
The MR image shows infarction of the left anterior column of the fornix. Typical presentation consists of memory deficit including amnesia with impairment of delayed recall. The subcallosal artery is a perforating branch of the anterior communicating artery and is an important vascular supply to the anterior column of the fornix, while the posterior choroidal branches of the posterior cerebral artery are an important vascular supply to the body of the fornix.
Projection axons in the olfactory tract originate in which of the following cells?
Answers:
A. Olfactory tract
B. Olfactory cells
C. Mitral cells of olfactory bulb
D. Piriform cortex
E. Entorhinal cortex
Mitral cells of olfactory bulb
Bipolar primary olfactory neurons originate in the olfactory cells within the olfactory epithelium, and project to secord order neurons in the olfactory bulb called mitral cells. Axons from mitral cells leave the olfactory bulb through the olfactory tract located under the frontal lobe to the primary olfactory cortex (piriform cortex), which is located on the inferior surface of the temporal lobe. The entorhinal cortex is an area of the brain’s allocortex, located in the medial temporal lobe, whose functions include being a widespread network hub for memory, navigation, and the perception of time.
Which of the following structures is most responsible for processing proteins for cellular secretion?
Answers:
A. Lysosomes
B. Nucleolus
C. Smooth endoplasmic reticulum
D. Golgi apparatus
E. Rough endoplasmic reticulum
Golgi apparatus
The Golgi apparatus is responsible for packing proteins produced by the rough endoplasmic reticulum into vesicles that are then released at the cell membrane. Lysosomes are membranebound organelles that contain hydrolytic enzymes that can break down many kinds of biomolecules. The nucleolus is the site of ribosome biogenesis. The endoplasmic reticulum (ER) is made up of two subunits – rough endoplasmic reticulum (RER), and smooth endoplasmic reticulum (SER). The two types of ER share many of the same proteins and engage in activities such as synthesis of certain lipids and cholesterol.
In the endoscopic view of the floor of the third ventricle shown, which of the following structures is
indicated by the arrow?
Answers:
A. Mammillary bodies
B. Infundibular recess
C. Lamina terminalis
D. Thalamus
E. Pineal gland
Infundibular recess
The infundibular recess is pictured. The endoscope is advanced through the foramen to visualize the third ventricle. The floor proper extends from the optic chiasm to the inlet to the cerebral aqueduct. The lamina terminalis lies anteriorly and rostrally. Immediately below the lamina terminalis, the optic chiasm will be apparent as a horizontal white or yellow band. Inferior to the chiasm is the infundibular recess, a brown or red dimple in the ependyma which gives rise to the pituitary stalk inferiorly. The infundibular recess is almost always visualized, is always midline, and serves as an anatomic landmark. The mammillary bodies lie posterior to the infundibular recess and are part of the posterior part of the hypothalamus. The third ventrile lies between the medial aspects of both thalami. The pineal gland lies posterior to the third ventricle.
A 36-year-old woman postpartum day 10 presents with a one-week history of headache and mild
confusion. MR imaging shows patchy diffusion restriction with surrounding edema and
intraparenchymal hemorrhage in the same region. MR venogram shows left transverse sinus
thrombosis. Which of the following is the most appropriate initial treatment for this patient?
Answers:
A. Warfarin
B. Aspirin
C. Heparin
D. Mechanical thrombectomy
E. Alteplase
Heparin
Both the American Stroke Association and European Stroke Association guidelines recommend commencing anticoagulation with heparin, even in the setting of venous sinus thrombosis causing intracranial hemorrhage. Thrombolysis and thrombectomy are reserved for cases of deteriorating neurological condition and commenced on a case by case basis. Warfarin is not suitable for initial anticoagulation due to the time taken to reach therapeutic levels. There is debate on whether Low Molecular Weight Heparin or Unfractionated Heparin are more appropriate, and the evidence for either is weak. The European guidelines favor low Molecular Weight Heparin due to lower rates of hemorrhagic complications, however the American Stroke Association states that either is appropriate.
Before intravenous administration of recombinant tissue plasminogen activator to treat a patient
with acute ischemic stroke, which of the following studies is most appropriate to obtain?
Answers:
A. PET
B. MR DWI
C. CT perfusion
D. CT angiogram
E. Non contrast CT
Non contrast CT
American Stroke Association guidelines on Acute Ischaemic Stroke 2018 recommend non-contrast CT imaging to rule out Intracranial Hemorrhage before commencing IV alteplase. Imaging to demonstrate large vessel occlusion or ischaemic reversibility are not required before commencing thrombolysis.
A 20-year-old man is evaluated because of a one-week history of intensely painful and recurrent
headaches accompanied by nasal congestion. The headaches develop in the right periorbital
region and last approximately 80 minutes. Which of the following findings is most likely to be found
on examination of the eyes during or soon after the headaches?
Answers:
A. Extra-ocular muscle palsy
B. Ptosis
C. Mydriasis
D. Miosis
E. Conjunctival injection
Conjunctival injection
Cluster headaches are a type of trigeminal autonomic cephalgia.They are orbital, supraorbital or temporal and last up to 180 minutes. They typically occur in men aged 20-40 years. They are associated with conjunctival injection, tearing, nasal congestion, facial/eyelid swelling, miosis or ptosis. Conjunctival injection and tearing are the most common features found in up to 80% of cases.
Which of the following venous drainage patterns of a dural arteriovenous malformation is most
predictive of an increased risk of hemorrhage?
Answers:
A. Drainage into a cortical vein with venous ectasia
B. Drainage into spinal perimedullary veins
C. Drainage into a dural sinus with retrograde flow in the sinus
D. Drainage into a dural sinus with retrograde flow in the sinus and cortical venous reflux
E. Drainage into a cortical vein
Drainage into a cortical vein with venous ectasia
This question asks you to know the Cognard classification of dural arteriovenous fistulae. There are various classification schemes for dAVFs, most commonly the Borden and the Cognard classifications. In each of the classification schemes, higher grades are associated with a higher rate of hemorrhagic presentation.
The correct answer to the question is drainage into a cortical vein with venous ectasia. This represents a Cognard grade 4 (Borden 3) lesion and was associated with the highest risk for hemorrhagic presentation in Cognard’s original description, and has been supported by more modern series as well. Drainage into a dural sinus with retrograde flow in the sinus (Borden 1, Cognard 2a) is a relatively low risk lesion; although there is retrograde flow in the sinus (implying occlusion of the ipsilateral sigmoid sinus), there is no evidence of venous strain or venous hypertension in this case and the hemorrhage risk is not particularly elevated. Drainage into a cortical vein (Borden 3, Cognard 3) does have a higher risk of hemorrhage than fistulae with drainage into a sinus, but the risk is lower compared with cases in which there is also venous ectasia.
Drainage into a dural sinus with retrograde flow in the sinus and cortical venous reflux (Borden 2, Cognard 2a+b) represents an intermediate risk lesion and is not the correct answer. Drainage into spinal perimedullary veins (Borden 3, Cognard 5) is not the correct answer. This is considered a high-risk feature, but these rare lesions most commonly present with evidence of myelopathy.
In the endoscopic view of the right foramen of Monro shown, which of the following structures is
indicated by the arrow?
Answers:
A. Thalamus
B. Choroid plexus
C. Fornix
D. Septum pellucidum
E. Lamina terminalis
Fornix
The foramen of Monro lies in the venous angle between the septal vein (medial) and the thalamostriate vein (lateral). Both veins join the internal cerebral vein. Between these veins lies the choroid plexus which runs rostral to the thalamus. The column of the fornix forms the anterior wall of the foramen, and the anterior pole of the thalamus forms the posterior wall. The septum pellucidum is a thin membrane separating the anterior horns of the left and right lateral ventricles. The lamina terminalis lies anteriorly and rostrally within the third ventricle.
A 40-year-old man has a 2-week history of diplopia. A CT scan, MR image, and angiograms are
shown. In addition to left abducens palsy, which of the following is the most likely finding on
physical examination?
Answers:
A. Horner’s syndrome
B. V1 distribution dysesthesia
C. Pupil-involving third nerve palsy
D. Pupil-sparing third nerve palsy
E. Fourth nerve palsy
Pupil-sparing third nerve palsy
The most common symptom of an enlarging cavernous aneurysm is diplopia, due to ophthalmoplegia. The third nerve palsy will classically not produce a dilated pupil because the sympathetics that dilate the pupil are paralyzed along with the nerve itself. Diplopia is found in over 60% of patients with symptomatic cavernous aneurysms. Headache, retro-orbital pain or pain in the V1 distribution is the second most common presenting symptom, seen in about 50-60% of cases in retrospective series. Cavernous aneurysms are associated with a higher risk of growth over time than intracranial aneurysms in other locations. Other causes of pupil-sparing oculomotor palsies include diabetic neuropathy, myasthenia gravis, chronic progressive ophthalmoplegia and vasculopathies (e.g. temporal arteritis). This is due to the fact that ischemic lesions affect the vasa nervorum, leading to infarction of the nerve but sparing the parasympathetic fibers that are located on the outside of the nerve. A CN3 palsy that involves the pupil is more commonly a symptom of lesions that compress the nerve after it exits the sinus, including chordomas, clival meningiomas, PCOM aneurysms or distal basilar aneurysms. A fourth nerve palsy is not as commonly seen as an abducens or oculomotor palsy and is most commonly seen in combination with a third nerve palsy. In the largest series of patients with cavernous aneurysms investigating natural history, fourth nerve palsy was never seen without other ocular motor nerve palsies. Dysesthesias in the distribution of the trigeminal nerve are relatively common findings in patients with cavernous aneurysms and are more commonly seen in the V1 distribution than V2 or V3, but are less common overall than oculomotor palsy. Corneal hypoesthesia is probably the most common trigeminal symptom associated with these lesions. Horner’s syndrome, consisting of pupillary constriction and partial ptosis, is a relatively common symptom in extracranial ICA dissection, but is not as common as isolated head or neck pain. In series of cavernous aneurysms, Horner’s pupil, which is caused by ocular sympathetic paresis without third nerve palsy, was very uncommon. The Horner’s syndrome of carotid dissection or aneurysm is postganglionic, and so anhidrosis is not seen.
The cerebral angiogram images demonstrate an anterior cerebral artery arteriovenous
malformation (AVM). Which of the following is the principal risk factor indicating a high risk for
hemorrhage in the illustrated AVM?
Answers:
A. Venous varix
B. Single draining vein
C. Deep AVM location
D. Feeding artery aneurysm
E. Diffuse nidus
Venous varix
Venous ectasia is the correct answer. This question asks you to identify high risk features for hemorrhage after examining the figure carefully. Remember, the Spetzler-Martin and LawtonYoung grading scales identify risk factors for surgical complications; they do not predict rupture risk of an unruptured AVM. The risks for rupture among patients with unruptured AVMs include angiographic, patient and demographic factors. Increasing age and prior ruptured status are important patient factors for future hemorrhage. Other factors associated with hemorrhage in retrospective cohorts in multivariate analyses include deep brain location, exclusive deep venous drainage, single draining vein, feeding artery aneurysm, and presence of venous varix or varices. Of these, the feature illustrated in this case, is venous varix. The figure demonstrates a small right medial frontal AVM that is fed primarily by a branch of the right ACA. The lateral view demonstrates that there are two main draining veins. One drains anteriorly into the superior sagittal sinus, and the other (major) draining vein drains into the deep drainage system. You can see the internal cerebral vein outlined in the figure. There is a venous varix just at the outflow point from the AVM and prior to the drainage into the internal cerebral vein. Deep AVM location is related to AVM hemorrhage risk, but the AVM illustrated here would not be considered a deep location. Deep location refers to basal ganglia, internal capsule, thalamus or corpus callosum. Feeding artery aneurysm is related to AVM hemorrhage risk, but the DSA illustrated here does not show any feeding artery aneurysm. Single draining vein is related to AVM hemorrhage risk, but as mentioned above this AVM has both superficial and deep venous drainage. Diffuse nidus is one of the elements of the Lawton-Young grading scale which is a supplementation to the Spetzler-Martin scale and helps predict neurological outcome and morbidity after surgery. It is not related to hemorrhage risk.
The cell viewed under electron microscopy in the figure shown is generally found adjacent to which
of the following?
Answers:
A. Neurons
B. Astrocytes
C. Microglia
D. Ventricle wall
E. Oligodendocytes
Ventricle wall
An ependymal cell is pictured. Ependymal cells line the ventricles and interface with the periventricular white matters. Tight junctions prevent CSF movement across this layer, but novel evidence has suggested a possible role in CSF production and homeostasis. Neurons are electrically excitable cells that communicates with other cells via specialized connections called synapses. They are the main component of nervous tissue. Astrocytes are characteristic starshaped glial cells in the brain and spinal cord. They perform many functions, including biochemical support of endothelial cells that form the blood–brain barrier, provision of nutrients to the nervous tissue, maintenance of extracellular ion balance, regulation of cerebral blood flow, and a role in the repair and scarring process of the brain and spinal cord following infection and traumatic injuries. Microglia are the macrophage cells of the brain an spinal cord. They act as the first and main form of active immune defense in the central nervous system. Oligodendrocytes create myelin sheath to support and insulate axons in the central nervous system.
A 73-year-old woman develops a brain-stem syndrome from loss of a paramedian perforator
caused by progressive enlargement of an aneurysm. CT angiograms three years apart are shown.
Which of the following deficits are most likely to be detected on this patient’s neurological
examination?
Answers:
A. ipsilateral facial numbness
B. contralateral hemianesthesia
C. ipsilateral hemiparesis
D. ipsilateral ophthalmoplegia
E. contralateral loss of facial pain and temperature
Correct Answer:
ipsilateral ophthalmoplegia
The aneurysm is causing mass effect on the left cerebral peduncle at the midbrain level. Involvement of perforators at this level may result in Weber syndrome from midbrain stroke. Weber syndrome typically involves the substantia nigra, corticospinal fibers, corticobulbar tract, and oculomotor nerve fibers. Common presenting symptoms include CNIII palsy, contralateral hemibody weakness, contralateral parkinsonism, and lower facial muscle wekaness. The aneurysm size on MRI appears larger than what is filling on the vascular imaging with CTA. Therefore, this likely represents a partially thrombosed aneurysm.
A 61-year-old man is evaluated for acute onset of a right homonymous hemianopia. Which of the
following vessels, thought to be the conduit for an artery-to-artery embolus, is indicated by the
arrow in the right internal carotid angiogram shown?
Answers:
A. Persistent proatlantal artery
B. Persistent trigeminal artery
C. Otic artery
D. fetal posterior communicating artery
E. persistent hypoglossal artery
Persistent trigeminal artery
A persistent trigeminal artery is the most common type of persistent fetal carotid-vertebrobasilar anastomoses: anatomical variants of arterial communications between the anterior and posterior circulations. The persistent trigeminal artery arises from the proximal cavernous internal carotid artery to join the basilar artery and may lead to posterior circulation embolic stroke originating from the carotid circulation. Other carotid-vertebrobasilar anastomoses include the hypoglossal artery, which originates from the internal carotid artery between C1-3 levels traversing the hypoglossal cannal to join the basilar artery, and the otic artery, which originates from the petrous internal carotid artery within the carotid canal and runs through the internal auditory canal to join the proximal basilar artery. The other anastomosis is the proatlantal artery which originates from the common, internal (Type I), or external (Type II) carotid arteries at the C2-4 levels and joins the vertebral artery at the suboccipital region after traversing the foramen magnum.
Which of the following areas is entered when opening the structure under the tip of the white arrow in the photograph shown?
Answers:
A. ambient cistern
B. third ventricle
C. sylvian fissure
D. interpeduncular cistern
E. interhemispheric fissure
third ventricle
The lamina terminalis is a thin sheet of gray matter and pia mater stretches upward between the optic chiasm and rostrum of the corpus callosum. It forms the anterior wall of the third ventricle. Its opening allows entry into the third ventricle and release of significant amount of CSF. This facilitates aneurysm dissection without excessive brain retraction. The ambient cistern is a thin, sheet-like extension of the quadrigeminal cistern that extends laterally around the midbrain. The interpeduncular cistern (or basal cistern) is an unpaired CSF-filled subarachnoid cistern located between the cerebral peduncles. It contains the proximal portion of the third cranial nerve and the basilar apex. The interhemispheric fissure lies within the midline and seperates both cerebral hemispheres. It contains the falx cerebri. The sylvian fissure is the subarachnoid space separating the frontoparietal and temporal lobes.
A 24-year-old woman on oral contraceptives is evaluated for new-onset headache and a
generalized seizure. A CT scan without contrast (Figure 1) and MR images without contrast
enhancement (Figures 2 and 3) are shown. Which of the following is the most appropriate
management?
Answers:
A. Reverse anticoagulants by administering FFP and/or specific reversal agents
B. Take for urgent cerebral angiogram
C. Initiate heparin infusion
D. Reverse antiplatelet medications and administration of platelets
E. Obtain MRI and MRV
Initiate heparin infusion
The correct answer is to initiate heparin infusion. The patient has a hemorrhage related to a transverse and superior sagittal sinus thrombosis, and the most important initial step is to start treatment with anticoagulant medication. Figure 1 demonstrates hyperdensity in the region of the left transverse sinus with a low-density area in the temporal lobe which is a likely area of venous infarct. Figures 2 and 3 demonstrate an area of hemorrhagic conversion. The hint in the question stem to clue you in to the diagnosis is that the patient is currently taking oral contraceptive. OCP use, pregnancy, local infection (e.g. otitis media), trauma, malignancy and sickle cell trait (among many other factors) are all associated with an increased risk of the development of cortical or dural sinus thrombosis. The most common locations for dural sinus thromboses are in the SSS and right transverse sinus. In cases of sinus thrombosis, treatment should be initiated immediately and aggressively, as this has been shown to reduce mortality and improve neurological outcomes. Administration of platelets or reversal of antiplatelet agents is usually among the first steps of management for hypertensive or general ICH. However, in this case, the better answer is to initiate heparin first. MRI is an excellent imaging tool for diagnosis and follow-up of cerebral venous thrombosis, but it would not be the best choice here. MRI can differentiate between clots of different ages, as well as differentiate cerebral edema and non-acute hemorrhage. MRV tends to over-estimate the degree of thrombosis. Catheter angiography is useful in diagnosis, although studies suggest that diagnostic accuracy of MRI and DSA are similar. DSA may falsely suggest an occluded transverse sinus when in fact nonopacified blood filling a sinus can mimic a filling defect. DSA can also be used for treatment, although this is typically reserved for patients who are refractory to, or have progressive neurological decline, despite anticoagulation. Reversal of anticoagulant medications and/or administration of specific agents such as andexanet or prothrombin complex concentrate (Kcentra), would not be recommended. Again, this is a recommended early course of action after hypertensive or general ICH. However, among patients with hemorrhage from sinus thrombosis, initiation of heparin therapy is the first step.
A previously healthy 40-year-old woman is evaluated because of a two-day history of severe
headache. Her only medication is an oral contraceptive. CT scan and CT angiography of the brain
are shown. Which of the following is the most appropriate next step in management of this patient?
Answers:
A. Reverse antiplatelet medications and administration of platelets
B. Initiate heparin infusion
C. Obtain MRI and MRV
D. Take for urgent cerebral angiogram
E. Reverse anticoagulants by administering FFP and/or specific reversal agents
The correct answer is to initiate heparin infusion. The patient has a hemorrhage related to a transverse and superior sagittal sinus thrombosis, and the most important initial step is to start treatment with anticoagulant medication. The figure shows the filling defect in the right transverse sinus, along with the associated venous hemorrhage. The hint in the question stem to clue you in to the diagnosis is that the patient is currently taking oral contraceptive. OCP use, pregnancy, local infection (e.g. otitis media), trauma, malignancy and sickle cell trait (among many other factors) are all associated with an increased risk of the development of cortical or dural sinus thrombosis. The most common locations for dural sinus thromboses are in the superior sagittal sinus and right transverse sinus. In cases of sinus thrombosis, treatment should be initiated immediately and aggressively, as this has been shown to reduce mortality and improve neurological outcomes. Administration of platelets or reversal of antiplatelet agents is usually among the first steps of management for hypertensive or general ICH. However, in this case, the better answer is to initiate heparin first. MRI is an excellent imaging tool for diagnosis and follow-up of cerebral venous thrombosis, but it would not be the best choice here. MRI can differentiate between clots of different ages, as well as differentiate cerebral edema and non-acute hemorrhage. MRV tends to over-estimate the degree of thrombosis. Catheter angiography is useful in diagnosis, although studies suggest that diagnostic accuracy of MRI and DSA are similar. DSA may falsely suggest an occluded transverse sinus when in fact nonopacified blood filling a sinus can mimic a filling defect. DSA can also be used for treatment, although this is typically reserved for patients who are refractory to, or have progressive neurological decline, despite anticoagulation. Reversal of anticoagulant medications and/or administration of specific agents such as andexanet or prothrombin complex concentrate (Kcentra), would not be recommended. Again, this is a recommended early course of action after hypertensive or general ICH. However, among patients with hemorrhage from sinus thrombosis, initiation of heparin therapy is the first step.
