Cerebral Vascular Accident/Test 3 Flashcards
Stroke:
- Third most common cause of death in the US and Canada
* After a stroke, nearly 25% will die within a year
Stroke/CVA/Brain attack occurs when
There is ischemia to a part of the brain or hemorrhage into the brain that results in death of brain cells.
The goals of stroke/cva/brain attack are:
-early recognition of s/s, dx&tx within 3 hours of onset, increase cerebral blood flow and reverse the ischemic process to the viable brain cells
Transient Ischemic Attack:
A temporary focal loss of neurologic function caused by ischemia of one of the vascular territories of the brain; lasts less than 24 hours and often less than 15 minutes
Risk factors for stroke/cva/brain attack. Nonmodifiable:
- Age
- gender
- men more likely to have stroke
- women more likely to die from it
- Race
- Hereditary
- Atherosclerosis
- thrombus formation contribute to emboli
Risk factors for stroke/cva/brain attack.
Modifiable
- Hypertentions-single most important modifiable risk factor
- Heart disease-a-fib, MI, cardiomyopathy, cardiac valve abnormalties and cardiac congenital defects
- Diabetes
- Cholesterol
- Smoking
- Excessive alcohol use
- Obesity
- Physical inactivity
- Poor diet
- Drug abuse
- Oral contraceptives
Warning signs of a stroke: FAST
Sudden onset:
- Face- weakness, numbness or loss of sensation on one or both sides of the body
- Difficulty speaking or understanding speech, confusion
- Severe headache, occuring without apparent reason or different from usual
- Dizziness, loss of balance or coordination, falling, unsteady gait without apparent reason
Pathophysiology of stroke:
Blood is supplied to the brain by 2 major pairs of arteries
- the internal carotid arteries (anterior circulation)
- the vertebral arteries (posterior circulation)
- Circle of willis unites the anterior and posterior circulations
- Auto regulation maintains blood flow at a rate of 750 ml/min
Anterior Cerebral Artery:
Supplies most of the medial surface of the cerebral cortex (anterior 3/4) frontal pole via cortical branches and anterior portions of the corpus callosum. Perforating branches (including the recurrent artery of Heubner and Medial Lenticulostriate arteries) supply the anterior limb of the internal capsule, the inferior portions of head of the caudate and anterior globus pallidus . Bilateral occlusion of anterior cerebral arteries at their stems results in infarction of the anteromedial surface of the cerebral hemispheres (SEE SLIDE)
Stroke Types
Ischemic
Hemorrhage
Ischemic stroke
A clot blocks blood flow to an area of the brain
Hemorrhage stroke
bleeding occurs from inside or around brain tissue
CT Scan will
indicate size and location
*differentiates between ischemic or hemorrhage
Clinical distinction between meningitis and encephalitis is based on
brain function
Meningitis
uncomfortable, lethargic, disctracted by headache but cerebral function remains normal
Encephalitis:
abnormalties in brain function are common, including altered mental status; motor or sensory deficits; speech/movement disorders
Ischemic stroke:
80% of all strokes
-inadequate blood flow from partial or complete occlusion
Thrombotic stroke
- injury to a blood vessel wall
- formation of a blood clot
- narrowed blood vessel lumen
- if it becomes occluded, infarction occurs
Embolic Stroke:
- embolus lodges in and occludes
- resulting in infarction
- What dysrhythmia predisposes patients to an embolic stroke-
Hemorrhagic stroke:
*bleeding into the brain tissue, subarachnoid space, or ventricles
Intracerebral hemorrhage
- caused by vessel rupture
* poor prognosis
Subarachnoid hemorrhage
*bleeding into the cerebrospinal fluid-filled space between the arachnoid and pia mater commonly caused by rupture of aneurysm