Anatomical Basis of Stroke Flashcards
The basilar artery bifurcates to give rise to ..
Where does this occur?
posterior cerebral artery
interpeduncluar fossa, just caudal to the mammillary bodies
The base of the posterior cerebral arteries give rise to…
which course along the lateral margin of the interpeduncular fossa (lateral to mammillary bodies) to anastomose with what?
posterior communicating artery
internal carotid artery
The rostral surface of the internal carotid artery gives rise to… that courses over…
anterior cerebral artery
the superior surface of the optic nerve
After giving rise to the anterior cerebral artery, the internal carotid continues superiorly as the …
middle cerebral artery
The paired anterior cerebral arteries are connected by a small…
typically near the level of the caudal end of …
anterior communicating artery
the olfactory tract
What is the arterial ring around the ventral surface of the brain at the level of the hypothalamus called?
Circle of Willis
Each half of the ring consists of (from caudal to rostral):
- posterior cerebral artery
- posterior communicating artery
- internal carotid artery
- anterior cerebral artery
- anterior communicating artery
The Circle of Willis is primarily supplied by what artery?
Internal carotid artery
What is the most important branch coming off of the Circle of Willis?
middle cerebral artery
The anterior cerebral artery, after passing over the superior surface of the optic nerve, enters the inferior aspect of the… to course along the surface of the ….
This artery follows an arching course caudally, remaining close to the superior surface of…
Longitudinal Cerebral Fissure
Cerebral Hemisphere
Corpus Callosum
What does the anterior cerebral artery perfuse?
- medial surface of the frontal and parietal lobes
- medial portion of the inferior (orbital) surface of the frontal lobe
- superolateral surfaces of the frontal and parietal lobe (less than 1 inch in breadth)
- perforating branches get the corpus callosum except for the caudal end (splenium)
The Cingulate Sulcus gives rise to two dorsally directed branches; one branch occurs over the body of the corpus callosum, typically remaining on the medial surface of the brain. What is the other branch called, and what direction does it go?
Marginal Sulcus
forms the caudal end of the cingulate sulcus and extends onto the superolateral surface of the brain
Immediately rostral to the marginal sulcus is a relatively small U shaped gyrus called…
Why is this an important landmark?
Paracentral gyrus
- caudal limb of the gyrus is the medial continuation of the somatosensory cortex (parietal lobe)
- while the rostral limb is the medial continuation of the primary motor cortex (frontal lobe)
How does the Central Sulcus anatomically relate to the Paracentral Gyrus?
it rests between the tips of the paracentral gyrus on the superior surface of the brain, but does not continue onto the medial surface
All of the medial surface of the brain superior to the cingulate sulcus and rostral to the paracentral gyrus is the …
superior frontal gyrus
The medial surface of the parietal lobe is represented primarily by a large rectangular field the …
What are its borders?
precuneus
- bordered rostrally by marginal sulcus
- caudally by parieto-occipital sulcus
- inferiorly by cingulate sulcus
What horizontal sulcus is present on the medial surface of the occipital lobe?
calcarine sulcus
The lobe dorsal to the calcarine sulcus is the … while the lobe ventral to the calcarine sulcus is the…
cuneus
lingual gyrus
What are common manifestations of CVAs involving the anterior cerebral artery?
- paralysis and sensory disruption in foot/leg
- urinary incontinence
- gait apraxia
- transcortical motor aphasia
- cognitive impairment
- ideomotor apraxia
What higher-order control centers are located in the paracentral gyrus? What artery supplies this area?
micturition and defecation
anterior cerebral artery
The superior frontal gyrus contains the supplementary motor cortex that is generally in charge of what that could be affected by an anterior cerebral artery stroke?
“normal” gait
What is transcortical motor aphasia? Where would there be injury in the brain that could cause this symptom?
difficulty with spontaneous vocalization
antero-superior portion of frontal lobe
Ideomotor apraxia, the inability to perform simple hand gestures, particularly with tool use is a manifestation of damage to what?
corpus callosum
What does the posterior cerebral artery perfuse off of its main branches?
- inferior surface of temporal lobe except for the rostral tip (temporal pole)
- far enough laterally to cover a strip on the inferolateral surface of the temporal lobe
- inferior to medial surface of occipital lobe
- all of the medial surface of occipital lobe
- lateral surface of occipital pole
What does the posterior cerebral artery course over? As it goes over this, what branches does it give rise to?
cerebral peduncle
perforating branches - thalamic branches
What do thalamic branches of the posterior cerebral artery perfuse?
- crus cerebri
- substantia nigra
- caudal portion of the thalamus
The portion of the frontal lobe medial to the olfactory sulcus is called what? The portion lateral to the olfactory sulcus is called what?
gyrus rectus
orbital gyrus
The uncus sits at the same level as what other prominent feature?
mammillary bodies
The uncus is part of what gyrus?
parahippocampal gyrus
What sulcus is medial to the parahippocampal gyrus?
What sulci are lateral to the parahippocampal gyrus?
parahippocampal sulcus
Rhinal sulcus (rostrally)
Collateral sulcus (caudally)
What is between the inferior temporal sulcus (laterally) and the collateral and rhinal sulci (medially) on the inferior surface of the temporal and occipital lobes?
occipitotemporal gyri
What forms the inferomedial surface of the occipital lobe?
lingual gyrus
What will be clinical deficits of a posterior cerebral artery CVA?
- blindness or other visual defects
- memory deficiencies
- partial or total anosmia
The primary visual cortex and the visual association cortex are perfused by what vessel?
posterior cerebral artery
Why would you get memory deficiencies with a posterior cerebral artery CVA?
perfusion of the parahippocampal gyrus and the underlying hippocampus would be stunted
Anosmia is seen with CVA to posterior cerebral artery because it disrupts the olfactory cortex which is found where?
area around the rhinal sulcus, the underlying amygdala
The middle cerebral artery originates from the internal carotid and courses…
laterally in the rostral end of the lateral sulcus
The initial part of the middle cerebral artery gives rise to multiple perforating branches named…
What do they perfuse?
Striate Arteries
- basal ganglia,
- red nucleus,
- majority of the internal capsule
- posterior crus and genu
The striate artery that originates most proximally off of the middle cerebral artery is called…
Artery of Cerebral Rupture
Besides giving off striate arteries, the middle cerebral artery also gives off branches to perfuse what other areas?
inferolateral surface of occipital lobe
temporal pole
The middle cerebral artery reaches the lateral surface of the brain and deflects caudally along the lateral fissure. During this part of its route, what does it perfuse?
majority of teh lateral surfaces of the frontal, parietal, occipital, and temporal lobes of the brain
What sulcus courses roughly horizontally across most of the parietal lobe, beginning just caudal to the postcentral sulcus?
What two lobules does it create?
intraparietal sulcus
creates superior and inferior parietal lobules
What two sulci are within the inferior parietal lobule?
caudal end of the lateral fissure
caudo inferiorly the caudal end of teh superior temporal sulcus
What is the area around the caudal end of the lateral sulcus called?
supramarginal gyrus
What is the area surrounding the caudal end of the superior temporal sulcus called?
angular gyrus
How is the lateral surface of the occipital lobe divided?
into superior and inferior occipital gyri
What are common deficits seen with a middle cerebral artery CVA?
- paralysis and hyperesthesia in face and arm
- breakdown of conjugate gaze
- “global” aphasia
To cause damage of sensory and motor function, what was the middle cerebral artery perfusing?
lateral portion of the premotor cortex
striate arteries got internal capsule with corticobulbar and corticospinal tracts and somatosensory radiation from the thalamus
How does a middle cerebral artery CVA damage conjugate gaze?
both frontal eye fields and parietal eye fields are perfused by the middle cerebral artery
What is damaged when the middle cerebral artery has a CVA and the pt now has aphasia?
Broca’s (inferolateral frontal lobe) and Wernicke’s area (between superior temporal gyrus and the angular gyrus)
The middle cerebral artery does not perfuse…
peripheral margin of any of the lobes of the brain
The posterior cerebral artery does not perfuse..
What artery does?
the temporal pole
middle cerebral artery
The middle cerebral artery does not perfuse the inferomedial portion of…
the frontal lobe
