Neuroanatomy Flashcards
- A lateral view or the cerebrum is shown in Figure 1. During a pterional exposure or the Sylvian fissure you encounter significant brain swelling. In order to achieve rapid brain relaxation, the BEST point to access the frontal horn or the lateral ventricle with a catheter would be at number.
A.5
B. I
C. 2
D. 3
E. 4
C. 2
The neurosurgeon should have a see-through type awareness of the position of the deep structures in relation to the cortical surface. The frontal horn is located deep to the inferior frontal gyrus (2), the atrium is located deep to the supramarginal gyrus (3), and the temporal horn is located deep to the middle temporal gyrus (6) The fomtal horn could also be cannulated through the middle frontal gyrus (1) With a catheter oriented perpendicular to the cortical surface This area however would not be typically exposed in a pterional approach.
- A lateral view of the cortical surface bordering the right sylvian fissure that is commonly exposed in a frontotemporal craniotomy IS shown in F’19ure 1. The lower ends of the preoen1ral (1) and post central (2) are are in the exposure. The supramarginal gyrus is indicated by number :
A. 9
B. 5
C. 6
D. 8
E. 7
E. 7
The surface of the inferior frontal gyrus is formed, from anterior to posterior. by the pars orbitalis (6), pars triangularis (5). and pars operrularis (4). The precentral gyrus (1) is positioned juSI behind the pars operrularis. The area below the lower apex of the pars triangular (4), .Which is commonly retractcd upward, away from the sylvian fissure, is the widest point along the fissure and a suitable point to begin opening the fissure. The postcentral gyrus (2) iS located just anterior to the supramarginal gyrus (7), which wraps around the uptumed posterior end of the sylvian fissure. The angular gyrus (8) is behind the supramarginal gyrus. The lower part of the pre- and postcentral gyri are commonly exposed at the posterior-superior edge of a frototemparal craniotomy in the area between the pars operrularis and the supramarginal gyrus. The transverse temporal gyri on the operrular surface of temporal lobe produce prominences (9 and 10) along the lower margin of the sylvian fissure at their lateral end. The most anterior of these is Heschi gyrus (9). A gyral bridge (3) commonly connects the lower ends of the pre and post central gyri and separates the lower
- A view from above Into the anterior part of the third ventricle is shown In Figure 1. The BEST location for performing a third ventriculostomy is indicated by number:
A. 8
B. 5
C. 6
D. 9
E. 7
A. 8
This view into the anterior part of the third ventricle exposes the columns of the fornix ( 1 ), inferior to the foramen of Monro, and the anterior commissure (2), crossing the anterior wall of the third ventricle in front
of the columns of the fornix (1) and just above the lamina terminalis (3). The chiasmatic recess (5) is located between the upper margin of the posterior edge of the optic chiasm (6) and the lamina terminalis (3).
The posterior edge of the optic chiasm (6) is located below the chiasmatic recess. The infundibular recess (7) extends into the base of the pituitary stalk, and the mamillary bodies (9) are located above the apex of
the basilar artery. An endoscopic third ventriculostomy would be completed at (8), where the floor of the third ventricle is thinnest.
- During a retrosigmoid approach for a small vestibular schwannoma resection, the artery shown In the figure(arrow) Is most at risk for injury. This vessel Is the:
A. Superior cerebellar artery.
B. Anterior Inferior Cerebelar artery
C. Posterior Inferior Cerebelar Artery
D. Vertebral artery.
E. Basilar Artery
B. Anterior Inferior Cerebelar artery
The anterior inferior cerebellar artery (AICA) Is most at risk during resection of a vestibular schwannoma regardless of approach. It can have a variable orientation in the CPA and meatus. In up to 40% of the cases it may actually deep Inside the IAC thus making it vulnerable to Injury even via a middle fossa approach.
- Figure 1 shows a posteorlorvlew of the fourth ventrlde. Willett of the foUowlng numbered structures represents the hypoglossal trigone area?
A. 3
B. 2
C. 1
D. 5
E. 4
D. 5
The median sulcus (1) divides the floor longitudinally in the midline. Each halter the floor Is divided
longitudinally by an Irregular sulrus. the sulcus limitans. which deepens lateral to the facial colliculus (2) and hypoglossal triangles (5) to form the superior (1) and Inferior foveae, respectively. The inferior fovea is located lateral to the hypogossal nucleus (5). A darkened area of cells, the locus ceruleus (8), is located at the rostral end of lhe sulcus limitans and medial to the superior cerebellar peduncle (6). The hypoglossal (5) and vagal (3) nuclei and the area postrema (4) are stacked one above the other in the lower part of the floor to give the configuration of a pen njb; thus, the area Is referred to as the calamus scriptorius. The stria medullaris crosses the floor at the level of the lateral recess.
- The BEST description of the relationship between the oculomotor nerve (CN III), P1 segment of the PCA and the SCA is that:
A. It has inconsistent relationship to the PCA and the SCA
B. It runs above PCA and the SCA
C. It runs between the PCA and the SCA
D. It runs below the PCA and the SCA
C. It runs between the PCA and the SCA
Once the oculomotor nerve exits the midbrain it reliably travels between the P1 segment of the PCA and the SCA
- Three days after clipping of a ruptured anterior communicating artery aneurysm, a patient develops contralateral paresis of the arm and face. as well as dysarthria A cerebral angiogram reveals focal vasospasm that eventually results in infarction of the corresponding vascular territory, confirmed by CT. What vessel was most likely affected by vasospasm in this case?
A Recurrent artery of Heubner
B. Anterior choroidal artery
C. Distal anterior cerebral artery
D. M1 branch of the middle cerebral artery
E. Posterior Communicating Artery
A Recurrent artery of Heubner
The recurrent artery of Heubner (also known as the medial distal striate artery) arises just distal (and less commonly proximal) to the anterior communicatmg artery. It supplies the head of the caudate. anterior limb of the internal capsule, anterior putamen and globus pallid us, the septal nuclei, and the inferior frontal lobe. It is termed & idguo;recurrent” due to its course from its origin backwards towards the ipsilateral Proximal A1 The artery is often at nsk of mjury during surgical treatment of an anterior communicating arterY aneurysm and may develop subsequent vasospasm. COmpromise of blood flow in the recurrent artery of Heubner classically results in contralateral arm and face weakness, and occasionally dysarthria.
Bilatera injury results in akinetic mutism. The CT image demonstrates infarction of the caudate head and internal capsule resulting from vasospasm of the recurrent artery of Heubner.
- What structure passes through the foramen demonstrated with the white arrow?
A. V2
B . V1
C. Vidian nerve.
D. VJ
E. Optic nerve.
A. V2
V2 travels throu h the foramen rotundum, which is the structure identified in the coronal CT in the figure. The foramen shq’wed immediately inferior and medially located inside the sphenoid bone is the pterygoid canal, Which contams the vidian nerve. The superior orbital fissure (SOF) is seen above the foramen rotundum and the optic canal s seen above the SOF.
- Which of the following structures of the superior orbital fissure pass around the annulus of Zinn:
A. Nasodliary nerve.
B. Inferior branch of oculomotor nerve.
C. Superior branch of oculomotor nerve.
D. Abducens nerve.
E. Trochlear nerve.
E. Trochlear nerve
The correct answer is the trochlear nerve. Four structures pass lateral to the annulus of Zinn in the superior fissure. These structures are the lacrimal nerve, the ophthalmic vein. the frontal nerve and the trochlear nerve.
Both inferior and superior branches of the oculomotor nerve pass through the annulus of Zinn as does the abducens nerve and the nasociliary nerve.
