Advanced Posterior Cerebral Artery Quiz

Q1. Why can a unilateral occipital PCA infarct produce contralateral homonymous hemianopia?

• Each occipital cortex represents only the ipsilateral eye
• One occipital visual cortex represents the opposite visual hemifield
• The PCA directly controls extraocular muscles
• The optic nerves cross completely at the chiasm

Q2. Which vascular arrangement can help explain macular sparing in some PCA territory infarcts?

• Complete absence of PCA supply to the macula
• Direct retinal projections to the cerebellum
• A separate cranial nerve for central vision
• Collateral flow to the occipital pole from middle cerebral artery branches

Q3. Why can a dominant PCA infarct involving the occipital cortex and splenium produce alexia without agraphia?

• Broca area is necessarily destroyed
• Visual information is disconnected from dominant language networks
• Reading is performed entirely by the cerebellum
• The primary hand motor cortex is necessarily destroyed

Q4. Why can a proximal PCA occlusion produce both thalamic and occipital deficits?

• All thalamic arteries arise from the MCA
• Both deep perforators and distal cortical branches can be compromised
• The PCA supplies only the occipital pole
• The thalamus is supplied by cerebral veins

Q5. How can proximal PCA disease directly affect the midbrain?

• The PCA enters the cervical spinal cord
• The PCA remains outside the subarachnoid space
• The midbrain is supplied exclusively by the ACA
• Proximal PCA perforators supply parts of the rostral midbrain

Q6. What is the artery of Percheron?

• A single PCA perforator supplying both paramedian thalami
• A venous channel connecting the thalami
• A meningeal branch supplying both frontal lobes
• A duplicated middle cerebral artery

Q7. Why can occlusion of the artery of Percheron cause bilateral paramedian thalamic infarction?

• The thalami receive blood only from one basilar perforator
• A single arterial trunk supplies both paramedian thalamic territories
• Both thalami normally share one MCA
• The artery drains both thalami into the straight sinus

Q8. Why can fetal-type PCA anatomy alter the consequences of internal carotid artery disease?

• The basilar artery becomes part of the venous system
• The PCA territory may depend substantially on internal carotid inflow
• The internal carotid supplies only the cerebellum
• The PCA no longer supplies neural tissue

Q9. Which relationship explains why vascular lesions near the proximal PCA can affect the oculomotor nerve?

• The oculomotor nerve lies within the basilar artery
• The oculomotor nerve accompanies the MCA in the lateral sulcus
• The oculomotor nerve passes through the ACA lumen
• The oculomotor nerve passes between the PCA and superior cerebellar artery

Q10. Which statement best integrates the anatomy of the posterior cerebral artery?

• It is an internal carotid terminal branch supplying only lateral frontal cortex
• It is a terminal basilar branch supplying visual cortex, inferomedial temporal cortex, and important deep structures
• It is a meningeal artery supplying only dura
• It arises from the ACA and supplies only the cerebellum