Ischemic Stroke Flashcards
Stroke is
Injury to the brain caused by interruption of bloodflow or by bleeding into or around. Produces teh abrupt onset of focal neurologic defects that frequently result in permanent disability or death.
Transient Ischemic attack
abrupt onset of focal neurological deficits that resolve in less than an hour.
What percentage of strokes are hemorrhagic and describe a hemorrhagic stroke
about 20%… Hemorrhagic strokes may be caused by bleeding into the parenchyma of the brain or around the surface of the brain.
Bleeding into parenchyma of brain called
Intracerebral hemorrhage
Bleeding around the surface of the brain called
subarachnoid hemorrhage
Ischemic stroke may have what 4 potential underlying causes?
1) Atherosclerotic occlusion of an intra/extracerebral blood vessel
2) Embolus
3) Lacunar infarcts ( disease of the lumen of small arterioles
4) 30% are cryptogenic (unknown cause)
Stroke risk factors
- Age: doubles each decade
- Gender: male at one and a half times higher risk
- Race: african americans
- Family Hx
Modifiable stroke risk factors
- HTN
- Diabetes
- Hyperlipidemia
- Smoking
- Carotid Artery Stenosis
- Atrial Fib
- Obesity
- Physical inactivity
In the absence of blood supplying glucose to the brain, each 100gm of brain has sufficient energy stores to last how long?
two and a half minutes. The brain has very little energy storage. Thus, important to keep blood flowing to it.
Hyperthermia and hyperglycemia accelerate and worse stroke brain injury
ok
Under normal conditions, neurons metabolize glucose delivered by the blood almost exclusively through what type of metabolism
aerobic
Within minutes of the loss of blood supply, brain energy stores are depleted through the metabolism of glucose via glycolytic pathways with the accumulation of lactic acid.
Lactic acid is bad. High temps will accelerate glycolytic lactic acid production as will high blood glucose levels. Body temperature and blood glucose should be brought down asap.
Ischemic core
The central area downstream of an embolus most affected by loss of bloodflow, fewer collaterals providing circulation.
Ischemic Prenumbra
Peripheral areas with less severe ischemia.
Ischemic core suffers irreversible injury how fast?
Within 1 hour or less
Ischemic prenumbra may survive for how long?
Hours
Therapeutic window for stroke intervention is generally recognized as being
4-6 hours
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