8. Physiology of cerebral ischemia and infarction **Ischemia produces** Biochemical Reactions Loss of ion homeostasis, Osmotically obligated water, anaerobic glucolysis Loss cell membrane function & Cytoskeletal integrity Cell death
9. Physiology of cerebral ischemia and infarction **Selective vulnerability** Most vulnerable = Neuron Follow by Astrocytes, oligodendroglia, microglia and endothelial cells
10. Physiology of cerebral ischemia and infarction **Collateral supply** Dual or even triple interdigitating supply : Subcortical white matter U-fiber, external capsule, claustrum Short arterioles from a single sourec : The cortex Large, long, single source vessels : Thalamus, basal ganglia, centrum semiovale
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12. Border zones / Vascular watershed Adult, term infants Fetus, preterm infant Cortex and cerebellum Deep periventricular region
40. Border zones / Vascular watershed Adult, term infants Fetus, preterm infant Cortex and cerebellum Deep periventricular region
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46. At 2 months of age, T1-weighted brain MR imaging shows high - signal regions in the periventricular area, atrophy of the white matter and serrated ventricular walls .
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Notas do Editor
CT scans were obtained for two patients with chronic infarctions . Note the marked hypodensity of each lesion with similar density similar to cerebrospinal fluid and how each conforms to a known vascular distribution - central sulcal middle cerebral artery stroke and posterior cerebral artery occipital stroke .