Term
| How do you describe a stroke? |
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Definition
| stroke is described as an acute episode of focal brain ischemia lasting longer than 24 hours |
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Term
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Definition
- 87% of strokes are ischemic
- AF is responsible for 15 to 20% of all ischemic strokes
- AF increases risk of stroke 5 fold
- Stroke is 3rd leading cause of death
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Term
| What are 2 types of strokes? |
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Definition
Hemorrhagic: due to a rupture of a blood vessel in the brain.
Ischemic: due to an occlusion of an artery in the brain or critically lowered blood flow to the brain. |
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Term
| what are 2 types of hemorrhagic strokes? |
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Definition
- Intracerebral (bleeding in the brain itself)
- Subarachnoid (bleeding between the brain and skull)
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Term
| What are 3 types of Ischemic Strokes? |
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Definition
- Thrombotic (ie; atherosclerosis).
- Embolic -thrombis fragment embolizes outside the brain and lodges
- Hypoperfusion - critically lowered blood flow to the brain
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Term
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Definition
| Transient Ischemic Attack - symptoms last less than 24 hours with no permanent damage. |
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Term
| What are the 4 major arteries to the brain. |
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Definition
| 2 Internal Carotid Arteries and 2 Vertebral which branch to form the anterior, middle and posterior cerebral arteries on both sides of the brain. |
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Term
| How does stroke disrupt brain function? |
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Definition
| stroke disrupts transmission of impulses from neuron to neuron, disrupting brain function. |
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Term
| what 2 regions result from a stroke? |
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Definition
Ischemic Core - the area of tissue death also called the infarct.
Ischemic penumbra - area surrounding the core of functionally impaired but structurally intact tissue. |
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Term
what harmful events occur as neurons become depleted of energy?
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Definition
- neuron flow into and out of ions becomes unregulated
- cell membranes and other proteins are damaged.
- excitatory compounds such as glutamate accumulate
- the abnormal ion movement causes water to move into the neurons and other nervous system cells, resulting in edema and swelling.
- whater can also accumulate outside of the cells resulting in interstitial edema that can cause increased intracranial pressure, vascular compression and herniation.
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Term
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Definition
- acute onset of a painless, focal neurologic deficit
- also: sudden numbness, weakness or paralysis of the face leg or arm.
- visual disturbances
- speech disturbances
- memory impairment
- stumbling
- loss of balance or coordination
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Term
| Diagnostic process for stroke? |
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Definition
| take vitals, patient history, physical exam, neurologic exam, ct scan, blood studies, insert access IV, obtain brain CT for preliminary interpretation. |
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Term
| Only approved acute treatment for ischemic stroke is? |
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Definition
thrombolytic therapy with TIssue Plasminogen Activator (tPA) given within 3 hours of onset of stroke: recent update from acc/asa noted that in some cases administration of tpa up to 4.5 hours after onset may be appropriate
Other recommendations:
- against urgent anticoagulation such as with Heparin or LMWH
- ASA 325mg within 24 - 48 hours after onset of symptoms for most patients
- recommendation against clopidogrel or glycoprotein IIb/IIIa inhibitors.
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Term
| following acute management what is the focus of treatment? |
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Definition
| prevention of a subsequent stroke by addressing risk factors, including antithrombotic therapies. |
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Term
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Definition
- hemi paresis - weakness on one side of the body
- aphasia - impaired ability to communicate
- 30% of AF patients who have a stroke die within 1 year.
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Term
- Describe the sequence of events in normal coagulation
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Definition
- vascular spasm - the smooth muscle layer of the vessel wall immediately contracts
- Adhesion - the circulating platelets stick to the injured site
- Activation- these platelets become activated, changing in shape to better interact with each other and releasing a variety of chemical messengers
- aggregation - additional platelets converge on the site and stick to the existing platelets forming a platelet plug which is loose
- coagulation cascade - a series of reactions termed the coagulation cascade then occurs, which turns the loose platelet plug into a firm clot
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Term
| describe the virchow triad |
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Definition
- blood stasis- most important- in af the atria contract in an uncoordinated fashion and are often dilated. these factors enable blood flow to slow and blood to stagnate in te left atrium, particularly in the left atrial appendage or LAA
- endothelial dysfunction - changes in the endothelium include a rough wrinkled appearance that is thought to be due to edema and fibrosis
- hypercoagulable state - blood clots more readily in part due to increased levels of several coagulation related factors
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