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Flashcards in stroke and radiology Deck (17):
1

Most common cause of ischemic stroke

1/3 are from emboli: artery to artery (carotid/vertebral/aortic arch or intracranial stenosis) or cardiac source ( Afib, dilated cardiomyopathy, endocarditis/valvular dz)

2

Treatment of ischemic stroke

Primary/secondary prevention: treat HTN, DM, hypercholesterolemia, prophylactic treatment of carotid artery stenosis. Tertiary treatment: minimize long term effects from acute stroke

3

Describe cell death following stroke (ie. How long it takes to begin and how many cells die)

Cell death will begin in less than 5 minutes under normal conditions. 2 million neurons die per minute

4

Differential for sudden onset neurological deficit

Infarct, Transient ischemic attack, Seizure – post-ictal, Hematoma, Neoplasm

5

Time course of IV thrombolytic therapy

Need to know if there is ischemic but not infarcted brain tissue in <4.5 hrs.

6

Stroke protocol

Noncontrast head CT, Perfusion CT, CT angiogram of head and neck

7

What is non contrast CT used for in stroke

(look for hematoma, hemorrhage, neoplasm, large infarct or other contraindication for antithrombolytic agent)

8

What is perfusion CT

Using an intravenous contrast bolus determine the amount of blood flow, blood volume and timing of the bolus to areas of the brain. Continuous imaging at 2 or 4 locations for about 1 minute. High dose of radiation

9

Perfusion CT algorithm for strokes

Increased time to start or mean transit time,
increased time to peak and decreased blood volume equals completed infarct. Increased time to start, increased time to peak and normal or increased blood volume equals brain at risk Increased time to start or mean transit time,
increased time to peak and decreased blood volume equals completed infarct. Increased time to start, increased time to peak and normal or increased blood volume equals brain at risk

10

CT angiogram -what is it

Using an intravenous contrast bolus and thin sections moving through the anatomy depict vascular anatomy

11

What does a CT of an infarct look like

Confined to a vascular territory. 1- 6 hours: loss of gray matter density. 6 hours – 4 days: progressive swelling and hypodensity. 4 – 14 days: return towards normal density and volume. 14 days on: – varying degrees of
hypodensity and volume lossConfined to a vascular territory. 1- 6 hours: loss of gray matter density. 6 hours – 4 days: progressive swelling and hypodensity. 4 – 14 days: return towards normal density and volume. 14 days on: – varying degrees of
hypodensity and volume loss

12

What does an infarct look like on MRI

1 hour – 10 days: bright on diffusion weighted imaging
Swelling and increased signal on FLAIR and T2-weighted scans follows same pattern as swelling ang and low density on CT. DWI great for small infarcts and telling new from old1 hour – 10 days: bright on diffusion weighted imaging
Swelling and increased signal on FLAIR and T2-weighted scans follows same pattern as swelling ang and low density on CT. DWI great for small infarcts and telling new from old

13

What is the NIH stroke scale

Score from 0-42 (higher score means greater neurological deficit). Based on Level of consciousness, language, gaze, extinction, face, motor, ataxia

14

Acute stroke treatment

IV thrombolytics – tpa: NINDS trial - established
benefit to administration within 3 hr window. Some evidence for extending window to 4.5 hrs
Intra-arterial thrombolytics: IA thrombolysis shown
beneficial up to 6 hrs. 2 FDA approved devices for
mechanical intracranial embolectomy (MERCI and
Penumbra). Several devices used off label
(balloons and stents) or in developmentIV thrombolytics – tpa: NINDS trial - established
benefit to administration within 3 hr window. Some evidence for extending window to 4.5 hrs
Intra-arterial thrombolytics: IA thrombolysis shown
beneficial up to 6 hrs. 2 FDA approved devices for
mechanical intracranial embolectomy (MERCI and
Penumbra). Several devices used off label
(balloons and stents) or in development

15

What is penumbra

Aspiration microcatheters + suction pump

16

Prognosis of basilar artery thrombosis

very poor without thrombolysis.  Significant improvement with treatmentcan occur up to 24 hours

17

stent-trievers

using a stent to remove a clot