Cranial Vascular Neurosurgery Flashcards
Which one of the following pathologies is most likely to give the appearances shown?
a. Atrial myxoma
b. Ehlers-Danlos syndrome
c. Fibromuscular dysplasia
d. Marfan syndrome
e. Polycystic kidney disease
c. Fibromuscular dysplasia
Fibromuscular dysplasia. FMD occurs predominantly in middle-aged women and most often affects the cervical ICA (75%). The vertebral (12%) and external carotid arteries may also be involved. Disease is bilat- eral in 60% of cases. Angiographic images, almost always with non-invasive techniques, demonstrate alternating luminal narrowing and dilatation, the resulting appearance often described as a “string of beads.” This “corru- gation” typically affects the mid ICA, usually 2 cm distal to bulb. Uni- or multifocal tubu- lar stenoses are less common, and where observed, the degree of stenosis is usually modest (less than 40%). FMD can occasion- ally be observed intracranially and is associ- ated with aneurysms.
Which one of the following pathologies is most likely to give the appearances shown?
a. Anterior communicating artery aneurysm
b. Basilar tip aneurysm
c. Posterior communicating artery aneurysm
d.Posterior inferior cerebellar artery aneurysm
e. Middle cerebral artery aneurysm
a. Anterior communicating artery aneurysm
Anterior communicating artery aneu- rysm. The classical flame shaped hemorrhage associated with acute rupture of these aneu- rysms is depicted.
A33-year-oldmanpresentswithspontaneous tinnitus and nausea. Which one of the follow- ing is most likely based on the imaging shown?
a. Arteriovenous malformation
b. Cavernous angioma
c. Hemangioblastoma
d. Intracerebral hemorrhage
e. Medulloblastoma
b. Cavernous angioma
Cavernous angiomas are mulberry-like lesions consisting of vascular spaces with lit- tle intervening tissue and hemorrhage of dif- ferent ages. The incidence of clinically symptomatic hemorrhage remains uncertain, but is less frequent than with cerebral AVMs or dural fistulae. A previous bleed and infra- tentorial location are the main prognostic factors for recurrent hemorrhage. Lesions in or close to the cerebral cortex may cause epilepsy. They are occasionally intraventric- ular or arise on a cranial nerve. They appear as relatively well-defined, dense, or calcified lesions on CT, which may show patchy con- trast enhancement. On MRI they appear multilobular with mixed but predominantly elevated T2 signal intensity centrally sur- rounded by a dark hemosiderin rim. Not sur- prisingly, susceptibility-based sequences are the most sensitive. They may be multiple, particularly in familial cases. In many clinical situations the discovery of a cavernoma rep- resents an incidental finding.
A 49-year-old man attends the Emergency department complaining of headache and vomiting for the last 2 days and now he has clumsiness of his left hand. There is no history of trauma. His GCS is 15/15. CT head shows there is a right sided acute subdural hematoma with midline shift of 5 mm. Which one of the following would you perform next?
a. CT intracranial angiogram
b. CT head with contrast
c. CT perfusion scan
d.MRI head with diffusion weighted sequences
e. Transcranial Doppler
a. CT intracranial angiogram
Occasionally, rupture of a cerebral aneurysm may cause an acute subdural hematoma, most frequently a posterior communicating artery aneurysm lying next to the free edge of the tentorium cerebelli. A dural arteriovenous fistula may also bleed into the subdural space. Angiography is therefore indicated following a spontaneous acute subdural hematoma, particularly in a young patient prior to craniotomy and evacuation of the clot.
Which one of the following is most likely given the image below?
a. Arachnoid cyst
b. Cavernous sinus meningioma
c. Craniopharyngioma
d. Giant MCA aneurysm
e. Pituitary macroadenoma
d. Giant MCA aneurysm
On MRI imaging, giant aneurysms have a charac- teristic appearance, as in this case. Findings include signal void consistent with flow in the pat- ent lumen; phase artifact related to flow, as is seen in this case; and heterogeneous signal intensity representing thrombi of varying ages.
A 46-year-old female presents with sudden onset right facial numbness, hearing loss, and diplopia. CT head was unremarkable. Which one of the following therapies may be most appropriate based on the subsequent imaging shown?
a. Anticoagulant therapy
b. Balloon Angioplasty
c. Intra-arterial nimodipine
d. Surgical clipping
e. Thrombolytic therapy
a. Anticoagulant therapy
The MRI shows a spon- taneous right vertebral artery dissection—the main treatment for which is anticoagulation or antiplatelet therapy once subarachnoid hemorrhage has been excluded. Intra-arterial thrombolytics have only been used in selected cases.
A 37-year-old man presents with seizures. Which one of the following is NOT thought to increase risk of hemorrhage in this type of lesion?
a. Deep venous drainage
b. Intranidal aneurysm
c. Prior hemorrhage
d. Single draining vein
e. Smoking
e. Smoking
Brainarteriovenousmalforma- tions (AVMs) are abnormal vascular anoma- lies within the brain, presumably congenital in nature, but tend to present later in life (20-40 years). There are several subgroups, including the glomerular (most common) and fistulous (less common) types of AVMs. AVMs, often pial-based, are defined by presence of arteriovenous shunting through a nidus of coiled and tortuous vascular con- nections that connect feeding arteries to draining veins, without a capillary bed. Most (approximately 60-70%) of AVMs are located in the cerebral hemispheres, 11-18% within the cerebellum, and 13-16% in the brainstem; 8-9% are deep-seated. Factors that increase risk of hemorrhage from an AVM include history of hypertension or pre- vious hemorrhage, flow-related aneurysm, intranidal aneurysm, deep venous drainage, deep (periventricular) location, small nidus size (<3 cm), high feeding artery pressure, slow arterial filling, and venous stenosis. Presence of intracranial hemorrhage indi- cates a poorer prognosis and is associated with an increasing morbidity and mortality. Presence of AVMs can lead to arterial steal phenomenon, venous congestion, gliosis, or hydrocephalus.
Which one of the following supraclinoid internal carotid artery aneurysm locations is most frequent?
a. Anterior choroidal artery aneurysm
b. Carotid bifurcation aneurysm
c. Hypophyseal artery aneurysm
d. Posterior communicating artery aneurysm
e. Supraopthalmic aneurysm
d. Posterior communicating artery aneurysm
Thirty-five percent of all intracranial aneurysms arise at one of the following five sites along the supraclinoid ICA
Which one of the following pathologies is most likely demonstrated by the angiogram
a. Anterior choroidal artery aneurysm
b. Basilar tip aneurysm
c. MCA bifurcation
d. PCA aneurysm
e. Supraopthalmic aneurysm
e. Supraopthalmic aneurysm
These typi- cally arise from the superior wall of the carotid artery at the distal edge of the origin of the ophthalmic artery close to the roof of the cavernous sinus. At this point, the ICA changes direction from superior toward pos- terior, so the maximal hemodynamic force is directed toward the superior wall of the carotid artery just distal to the ophthalmic artery. Therefore, these aneurysms project upward toward the optic nerve and are often large with complex, multi-lobulated shape. Surgical exposure may be difficult as the oph- thalmic artery has a variable origin and course and because multiple folds of the dura enclose the region of the optic foramen and clinoid process. Many are wide-necked aneu- rysms that may require remodeling tech- niques. Unruptured aneurysms may become symptomatic due to headaches or compres- sion of cranial nerves.
Which one of the following is most likely based on this AP view of a right ICA injection?
a. A1 branch of ACA
b. Acomm artery
c. MCA bifurcation
d. M3 branch of MCA
e. Superior hypophysial artery
e. Superior hypophysial artery
Superior hypophysial artery aneurysms arise just distal to the origin of the superior hypophysial artery from the medial or poste- rior wall of the ICA where the curvature of
the ICA is convex medially. In this location they lie lateral to the pituitary stalk and point medially under the optic chiasm. Medial expansion of the aneurysm may compromise the perforating arteries to the floor of the third ventricle, the optic nerves, the chiasm, the pituitary stalk, and the hypophysial vascu- lar supply.
Which one of the following clinical findings would you look for in this patient?
a. Abducens palsy
b. Absent corneal reflex
c. Bitemporal hemianopia
d. Oculomotor palsy
e. Pituitary dysfunction
d. Oculomotor palsy
The posterior communicating artery arises from the posterior wall of the ICA where it forms a posteriorly convex curve as it ascends to its termi- nal bifurcation under the anterior perforated sub- stance. These aneurysms arise near the apex of the posteriorly convex turn, immediately superior to the distal edge of the origin of the posterior communicating artery. They point downward and posteriorly toward the oculomotor nerve, so the posterior communicating artery is usually found inferomedial to the neck of the aneurysm (the anterior choroidal artery is found superior or superolateral to the neck of the aneurysm). The oculomotor nerve enters the dural roof of the cavernous sinus lateral to the posterior clinoid process and medial to a dural band that runs between the tentorium cerebelli and the anterior clinoid process. Posterior communicating artery aneurysms larger than 4-5 mm may compress the oculomotor nerve at its entrance into the dural roof, causing opthalmoplegia.
The aneurysm type shown below constitutes which one of the following proportions of all intracranial aneurysms?
a. 1%
b. 5%
c. 15%
d. 25%
e. 35%
b. 5%
Aneurysms arise at the apex of the T-shaped carotid bifurcation and point superiorly in the direction of the long axis of the pre-bifurcation segment of the artery. As they grow, they lie lateral to the optic chiasm and may indent the undersur- face of the anterior perforated substance. The perforating branches arising from the choroidal segment of the internal carotid and the proximal segments of the anterior and middle cerebral arteries are stretched around the posterior aspect of the neck and wall of the aneurysm.
Which one of the following pathologies is most likely demonstrated by the angiogram?
a. Anterior communicating artery aneurysm
b. Basilar artery aneurysm
c. Basilar invagination
d. Left PCA artery aneurysm
e. Superior hypophyseal artery aneurysm
a. Anterior communicating artery aneurysm
Aneurysms of the ACA typically form close to the anterior communicating artery complex. They constitute about 30% of all intracranial aneu- rysms and are considered one of the most com- mon types of aneurysm. They are frequently associated with anatomical variants. Aneurysms often occur when one A1 segment is hypoplastic and the dominant A1 gives rise to both A2s. In such case, the aneurysm arises at the level of the anterior communicating artery at the point where the dominant A1 segment bifurcates to give rise to both the left and right A2 segments. The direction in which the dome of the aneurysm points is determined by the course of the domi- nant A1 segment proximal to its junction with the anterior communicating artery. Thus, these aneurysms usually point away from the dominant segment toward the opposite side. Approaches to anterior communicating artery aneurysms must ensure that the anterior communicating artery and the adjacent recurrent artery of Heubner remain patent. The AcomA gives rise to small perforating branches for the dorsal surface of the optic chiasm and suprachiasmatic area that perfuse the fornix, corpus callosum, and septal region. Occlusion of the anterior communicating artery may lead to personality disorders, even if both A2 segments are perfused from their respec- tive A1 segments. The recurrent artery of Heubner arises, variably, from the distal A1, the proximal A2, or the frontopolar branch of the ACA before looping forward on the gyrus rectus or the posterior part of the orbital surface of the frontal lobe and then passing back over the carotid bifurcation to accompany the MCA and enter the anterior perforating substance.
Occlusion of the recurrent artery of Heubner may cause hemiparesis or aphasia.
The following appearances are seen during endovascular treatment of an anterior communicating artery aneurysm. What is the next appropriate management step?
a. Ask the anesthetist to reduce systolic blood pressure to 100 mmHg
b. Check pupillary reflexes and perform CT head
c. Continue with endovascular treatment
d. ICP monitoring
e. Insertion of external ventricular drain
b. Check pupillary reflexes and perform CT head
Check pupillary reflexes and perform CT head. This angiogram shows active extravasation of contrast material into the subarachnoid spaces, suggesting acute rupture of this aneurysm necessitating clinical reassessment and surgical intervention if appropriate.
Which one of the following pathologies is most likely demonstrated by the angiogram?
a. A1 branch of ACA aneurysm
b. Corpocallosal AVM
c. MCA bifurcation aneurysm
d. Pericallosal aneurysm
e. Posterior communicating artery aneurysm
d. Pericallosal aneurysm
The second most common aneurysm of the ACA
is the so-called pericallosal aneurysm, which arises at the origin of the callosomarginal artery from the pericallosal artery, usually in close prox- imity to the anterior portion of the corpus callo- sum, near the point where the genu of the ACA has its greatest angulation. Pericallosal aneurysms account for approximately 3% of all intracranial aneurysms. They point distally into the window between the junction of the pericallosal and callo- somarginal arteries.