1	"G.A" G.A. Christoforidis, M. Kontzialis
2	"Review the pathophysiology of acute..." Review the pathophysiology of acute ischemic stroke including: Cascade of events leading to cell demise The penumbra concept Thresholds of metabolic disturbances and imaging thresholds Pathophysiologic events on cellular level Tissue viability contributing factors Review of an imaging-based treatment algorithm in acute ischemic stroke Review of endovascular treatment of acute ischemic stroke Treatment modalities Patient selection criteria Advantages/disadvantages of each method Review of predictors of stroke outcome Imaging Clinical
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10	"Non-contrast CT" Non-contrast CT T1W1 gradient echo T2*
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12	"Hyperdense MCA sign" Hyperdense MCA sign→ hyperdense arterial thrombus Loss of gray-white interface → Since gray matter is normally denser than white matter as a result of greater blood volume, oligemia leads to greater density loss in gray matter relative to white matter.
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19	"Relative Mean transit time (..." Relative Mean transit time (rMTT): Time for a bolus of contrast to travel through microvasculature relative to normal brain. The larger the delay the worse the less likely to have recovery. bad if ↑ Relative Cerebral blood flow (rCBF): Ratio of rCBV to rMTT. The lower the cerebral bad if ↓ Relative Cerebral blood volume (rCBV): Volume of contrast medium during first pass bolus of contrast. bad if ↓
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23	"Whereas MRP and CTP provide..." Whereas MRP and CTP provide relative perfusion values, xenon CT and PET imaging can provide absolute threshold values. The following table suggests approximate threshold values for irreversible ischemic damage in gray and white matter.
24	"Pial collateral score" Pial collateral score: Evaluation of delayed venous phase Angiographically visible pial collateral anatomic extent relative to site of occlusion Intraobserver agreement identical in 46/53
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27	"Intravenous tPA (3-hour window" Intravenous tPA (3-hour window) Intra-arterial thrombolysis (6-hour window) Mechanical thrombolysis MERCI retriever (8-hour window) Penumbra (8-hour window) Ultrasonification - ECOS Microsnare Laser thrombolysis Thrombus obliteration devices Percutaneous balloon angioplasty Stent placement
28	"The goal of endovascular treatment..." The goal of endovascular treatment for acute ischemic stroke is to recanalize the offended vessel and reperfuse the affected territory. Note that the term recanalization refers to the extent of removal of the offending thrombus, whereas reperfusion refers to the extent to which affected territories receive increased blood flow following recanalization. Several scoring systems have been developed to asses recanalization and reperfusion seperately The following slide presents example scoring systems for recanalization and reperfusion. Because these treatments are associated with potential life-threatening risks, adhering to patient selection criteria helps optimize results.
29	"Mori score for reperfusion" Mori score for reperfusion 0 for no reperfusion to the affected territory 1 for reperfusion of less than 50% of the affected territory 2 for reperfusion more than 50% of the affected territory but without complete reperfusion 3 for complete reperfusion of the affected territory. AOL score for recanalization 0 for no recanalization of the primary lesion 1 for incomplete or partial recanalization of the primary occlusive lesion with no distal flow 2 Incomplete or partial recanalization of the primary occlusive lesion with any distal flow 3 Complete recanalization of the primary occlusion with any distal flow
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33	"Angiography helps confirm tPA is..." Angiography helps confirm tPA is delivered throughout the offending thrombus to maximize the surface area of thrombus exposed to tPA.
34	"Method 1 (n=13" Method 1 (n=13) = Continuous microcatheter t-PA infusion within the clot randomly Method 2 (n=28) = t-PA infusion with intermittent microwire placement for manipulation within the clot (t-PA was not delivered around the wire) Method 3 (n=45) = Repeated microcatheter repositioning to distribute t-PA throughout the clot
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40	"Patients with a thrombus involving..." Patients with a thrombus involving a cerebral vessel distal to a parent vessel with a high grade stenosis can benefit from reconstitution from angiogplasty and stent. Re-establishment of flow to a territory containing a vessel occluded can lead to spontaneous resolution of an offending thrombus as illustrated in the following three cases.
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45	"Clinical Predictors for outcome" Clinical Predictors for outcome serum glucose level history of diabetes presenting NIHSS score time to treatment occlusion site extent of reperfusion Imaging Predictors for outcome pial collateral formation extent of diffusion abnormality CT hypodensity (ASPECTS score) perfusion (mean transit time) to the involved territory on MRI, CT SPECT or PET imaging.
46	"Clinical Predictors for hemorrhage" Clinical Predictors for hemorrhage systolic blood pressure serum glucose level history of diabetes platelet level presenting NIHSS score time to treatment occlusion site extent of reperfusion Imaging Predictors for hemorrhage pial collateral formation large diffusion abnormality CT hypodensity on presentation poor perfusion to the involved territory
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51	"Tissue viability in acute ischemic..." Tissue viability in acute ischemic stroke depends on the time to treatment, the severity of the ischemic insult, individual susceptibility determinants and therapeutic intervention Treatment is guided by the time to treatment, the presence of salvageable tissue on imaging, individual conditions and thrombolysis contraindications, and operator experience and familiarization with newer modalities Outcome in acute ischemic stroke is influenced by both imaging and clinical predictors
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53	"Which of the following is..." Which of the following is true concerning infarction cerebral blood flow thresholds (CBF) and CBF thresholds of metabolic disturbances during acute ischemic stroke? The thresholds are usually time dependent Gray matter has lower infarction threshold than white matter Neuronal loss occurs only below the infarction threshold The SI rise in DWI in the first few hours following ischemic stroke is due to vasogenic edema Density loss on CT occurs at a blood flow range higher than the SI rise in DWI
54	"Which of the following is..." Which of the following is true concerning infarction cerebral blood flow thresholds (CBF) and CBF thresholds of metabolic disturbances during acute ischemic stroke? The thresholds are usually time dependent Gray matter has lower infarction threshold than white matter Neuronal loss occurs only below the infarction threshold The SI rise in DWI in the first few hours following ischemic stroke is due to vasogenic edema Density loss on CT occurs at a blood flow range higher than the SI rise in DWI
55	"Which imaging method is more..." Which imaging method is more accurate in identifying tissue with irreversible ischemic damage during hyperacute (< 8 hrs) ischemic stroke? Non-contrast CT Relative mean transit time map on perfusion CT FLAIR MRI Diffusion weighted imaging Relative mean transit time map on perfusion MRI
56	"Which imaging method is more..." Which imaging method is more accurate in identifying tissue with irreversible ischemic damage during hyperacute (< 8 hrs) ischemic stroke? Non-contrast CT Relative mean transit time map on perfusion CT FLAIR MRI Diffusion weighted imaging Relative mean transit time map on perfusion MRI
57	"A patient with acute ischemic..." A patient with acute ischemic stroke symptoms undergoes cerebral angiogram. The neurointerventionalist reports good (grade 2) pial collateral circulation and complete recanalization of an m1 occlusion using intra-arterial thormbolytics. The patient has no history of diabetes and high platelet levels. Which of the following is true? The patient has increased risk for intracerebral hemorrhage The patient has favorable predictive factors Stent placement is necessary The patient may benefit from platelet transfusion Prophylactic craniotomy should be performed in case the patient hemorrhages.
58	"A patient with acute ischemic..." A patient with acute ischemic stroke symptoms undergoes cerebral angiogram. The neurointerventionalist reports good (grade 2) pial collateral circulation and complete recanalization of an m1 occlusion using intra-arterial thormbolytics. The patient has no history of diabetes and high platelet levels. Which of the following is true? The patient has increased risk for intracerebral hemorrhage The patient has favorable predictive factors Stent placement is necessary The patient may benefit from platelet transfusion Prophylactic craniotomy should be performed in case the patient hemorrhages.
59	"Acute ischemic stroke patient presents..." Acute ischemic stroke patient presents 4 hours after the onset of symptoms. No hemorrhage on CT. DWI/PWI is shown. What is the most appropriate course of action? IV thrombolysis IA thrombolysis Mechanical recanalization No intervention at this point, the infarct is complete No intervention at this point, because DWI revealed hemorrhage
60	"Acute ischemic stroke patient presents..." Acute ischemic stroke patient presents 4 hours after the onset of symptoms. No hemorrhage on CT. DWI/PWI is shown. What is the most appropriate course of action? IV thrombolysis IA thrombolysis Mechanical recanalization No intervention at this point, the infarct is complete No intervention at this point, because DWI revealed hemorrhage
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62	"The three leaders shown" The three leaders shown, besides their Alliance and their will to defeat Germany, they had another thing in common. What is it? The formed the first stroke coalition. They all instituted programs for ischemic stroke research. All suffered a stroke around the time of the Yalta conference. They all visited New Orleans They had nothing in common
63	"The three leaders shown" The three leaders shown, besides their Alliance and their will to defeat Germany, they had another thing in common. What is it? The formed the first stroke coalition. They all instituted programs for ischemic stroke research. All suffered a stroke around the time of the Yalta conference. They all visited New Orleans They had nothing in common