FNS 32 Vasculature of the Brain

  1. What is ischemia?
    Inadequate blood supply to an area
  2. What is infarction?
    Death of tissue due to ischemia
  3. "Bleeds"
    • Hemorrhage into the brain or subarachnoid space
    • Often from aneurysm
  4. What is an aneurysm?
    • Congenital abnormal sac on vessel
    • Weakens vessel wall
  5. "Blocks"
    1. Slow
    2. Fast
    • Occulisve process
    • 1. Arteriosclerosis produces thrombus
    • 2. Embolus produces sudden occlusion
  6. Transient Ischemic Attacks
    Temporary deficits (cerebral or retinal)
  7. Transient Global Amnesia
    • Temporary Memory disturbance
    • Anoxia of the hippocampus
  8. Major Vertebral A. Branches and supplied areas
    • Anterior Spinal Artery - medial medulla
    • Bulbar Branches - lateral medulla
    • Posterior Inferior Cerebellar Artery - lateral medulla
    • Basilar Artery
  9. What is the result of an Anterior Spinal A. Infarct?
    Inferior alternating hemiplegia
  10. What is the result of a PICA or Bulbar A. Infarct?
    • Lateral medullary snydrome of Wallenberg
    • - ipsilateral face - pain/thermal loss
    • - contralateral body - pain/thermal loss
    • - ipsilateral Horner's syndrome
  11. Major Basilar A. Branches and areas supplied
    • Anterior Inferior Cerebellar A. - caudal pons, caudal cerebellum
    • Labyrinthine A. - inner ear
    • Paramedian A. - medial pons
    • Circumferential A. - lateral pontine tegmentum
    • Superior Cerebellar A. - rostral pons, rostral cerebellum
    • Posterior Cerebral A. - crus cerebri
  12. What are the symptoms of a Paramedian Infarct?
    • Contralateral dorsal column deficits - medial lemniscus
    • Contralateral hemiplegia - corticospinal tract
    • CN III, VI, XII effected
  13. What are the symptoms of lateral Infarcts?
    • Ipsilateral Horner's syndrome
    • Ipsilateral V deficit
    • Contralateral spinothalamic deficit
  14. Major Branches of the ICA
    • Opthalmic
    • Posterior Communicating A.
    • Anterior Choroidal A.
    • Anterior Cerebral A.
    • Middle Cerebral A.
  15. What is the target of the cortical branches of the Circle of Willis?
    surface of the cerebral cortex
  16. What is the target of the central branches of the Circle of Willis?
    Deep structures (hypothalams, thalamus, basal ganglia, hippocampus, amygdala, globus pallidus)
  17. What are the Cortical branches of the Circle of Willis?
    • Anterior Cerebral A.
    • Posterior Cerebral A.
  18. Branches and targets of the Anterior Cerebral A.
    • Frontopolar A. - orbit and frontal lobe
    • Callosomarginal A. - Paracentral lobule and cingulate gyrus
    • Pericallosal A. - parietal lobe, precuneus, corpus callosum
  19. ACA Infarcts
    • Personality changes (prefrontal cortex)
    • UMN/sensory deficit in contralateral lower extremity (paracentral lobule)
  20. Branches and targets of the Posterior Cerebral A.
    • Anterior Br. - inferior temporal lobe
    • Calcarine A. - Primary visual cortex
  21. PCA Infarcts
    Contralateral homonymous hemianopsia (visual field)
  22. Target of the Middle Cerebral A.
    • Inf/middle frontal gyri
    • Pre/postcentral gyri
    • Sup/middle temporal gyri
    • Inf parietal lobule
    • Lat occipial lobe
  23. What is the Sylvian Triangle and what is its significance?
    • Insular branches of the MCA create a triangle shape
    • If displaced in angiogram, provides location of space-occupying lesion
  24. What is a "lacunar" infarct and why are we at risk?
    • Small, local infarctions due to bleeds or occlusions of small central branches of circle of willis
    • These do not anastomose effectively
  25. Branches and targets of the Medial Central branches of the Circle of Willis
    • Anteromedial - ant. hypothalamus and preoptic area
    • Posteromedial - post. hypothalamus, anteromedial thalamus, subthalamic nucleus
  26. Branches and targets of the Lateral Central branches of the Circle of Willis
    • Medial Striate (Huebner) - basal ganglia, ant. internal capsule
    • Lateral Striate (lenticulostriate) - basal ganglia, internal capsule
    • Posterior Lateral (thalamogeniculate) - post. thalamus
  27. What are the targets of the Anterior Choroidal A.?
    • Hippocampus
    • Amygdala
    • Globus Pallidus
    • Post. Internal Capsule
  28. Capsular Infarcts: affected fibers and resulting deficits
    1. Anterior limb
    2. Genus
    3. Posterior limb
    4. Retrolenticular Portion
    • 1. corticostriate - dyskinesia
    • 2. corticobulbar - central voluntary facial palsy
    • 3. corticospinal/somatosensory - contralateral hemiplegia and contralateral sensory loss
    • 4. optic & auditory radiations - contralateral homonymous hemianopsia, contralateral hearing diminution
Card Set
FNS 32 Vasculature of the Brain
FNS 32 Vasculature of the Brain