View stunning SlideShares in full-screen with the new iOS app!Introducing SlideShare for AndroidExplore all your favorite topics in the SlideShare appGet the SlideShare app to Save for Later — even offline
View stunning SlideShares in full-screen with the new Android app!View stunning SlideShares in full-screen with the new iOS app!
stroke is the clinical term for acute loss of circulation to an area of the brain, resulting in ischemia and a corresponding loss of neurologic function . Classified as either hemorrhagic or ischemic ,
Regions of the brain without significant flow are referred to collectively as the core, and these cells are presumed to die within minutes of stroke onset .
Zones of decreased or marginal perfusion are collectively called the ischemic penumbra .
Tissue in the penumbra can remain viable for several hours because of marginal tissue perfusion, and currently studied pharmacologic interventions for preservation of neuronal tissue target this penumbra
Arterial sources are atherothrombolic or cholesterol emboli that develop in the arch of the aorta and in the extracranial arteries ( ie, carotid and vertebral arteries ). Embolic strokes tend to have a sudden onset, and neuroimaging may demonstrate previous infarcts in several vascular territories
Thrombotic strokes include large - vessel strokes ( 70% ) and small - vessel or lacunar strokes ( 30% ).
They are due to in situ occlusions, characteristically on atherosclerotic lesions in the carotid, vertebrobasilar, and cerebral arteries, typically proximal to major branches . Thrombogenic factors include injury to and loss of endothelial cells exposing the subendothelium and platelet activation by the subendothelium, activation of the clotting cascade, inhibition of fibrinolysis, and blood stasis
Thrombotic strokes are thought to originate on ruptured atherosclerotic plaques .
Intracranial atherosclerosis may be the cause in patients with widespread atherosclerosis .
In other patients, especially younger patients, other causes should be considered, including coagulation disorders ( eg, antiphospholipid antibodies, protein C deficiency, protein S deficiency ) , sickle cell disease, fibromuscular dysplasia, arterial dissections, and vasoconstriction associated with substance abuse
Lacunar strokes represent 20% of all ischemic strokes .
They occur when the penetrating branches of the middle cerebral artery ( MCA ) , the lenticulostriate arteries, or the penetrating branches of the circle of Willis, vertebral artery, or basilar artery become occluded .
Causes of lacunar infarcts include microatheroma, lipohyalinosis, fibrinoid necrosis secondary to hypertension or vasculitis, hyaline arteriosclerosis, and amyloid angiopathy .
The great majority are related to hypertension .
Of all stroke types, lacunar strokes have the best prognosis
These infarcts, also known as border zone infarcts, develop from relative hypoperfusion in the most distal arterial territories and can produce bilateral symptoms . Frequently, these are associated with surgical procedures .
Stroke is the third leading cause of death in the United following cardiac diseases and cancer - related deaths . Approximately 29% of patients die within 1 year following a stroke; this percentage rises in patients older than 65 years .
Stroke is the leading cause of disability in the United States; 31% of stroke survivors need help in taking care of themselves after a stroke, 20% need some type of assistance for walking, and 16% need to be placed in some form of institution providing assisted living .
At least one third of stroke survivors have depression
Young blacks have a 2-3 times greater risk of ischemic stroke than the white population of the same age, and they are 2.5 times more likely to die of stroke .
White males have a stroke incidence of 62.8 per 100,000, with death being the final outcome in 26.3% of cases, compared with women who have a stroke incidence of 59 per 100,000 and a death rate of 39.2%
Hispanics have a lower overall incidence of stroke than whites and blacks but more frequent lacunar strokes and stroke at an earlier age
Focus medical history on identifying risk factors for atherosclerotic and cardiac disease, including hypertension, diabetes mellitus, tobacco use, high cholesterol, and a history of coronary artery disease, coronary artery bypass, or atrial fibrillation
In younger patients, elicit history of trauma, coagulopathies, illicit drug use ( especially cocaine ) , migraines, or use of oral contraceptives or over - the - counter medications ( especially those containing phenylpropanolamine
If the patient is a candidate for thrombolytic therapy, a thorough review of the inclusion and exclusion criteria from the NINDS trial must be performed . The exclusion criteria largely focus on identifying risk of hemorrhagic complication associated with thrombolytic use .
3-Cardiac : Cardiac arrhythmias, such as atrial fibrillation
4-Extremities : Carotid or vertebrobasilar dissections, and less commonly, thoracic aortic dissections, may cause ischemic stroke
5 -The neurologic examination must be thorough.
A directed and focused examination can be performed in minutes and not only provides great insight into the potential cause of the patient's deficits, but also helps determine the intensity of treatment required .
1-Glucose and Electrolyte disorders tests: Hypoglycemia is the most common electrolyte abnormality that produces stroke like symptoms . It is easily corrected, and correction leads to rapid resolution of symptoms .
Hyperglycemia and uremia should be considered carefully as the cause of ongoing mental and physical deficits.
2-Complete blood count : provides key information regarding hemoglobin and hematocrit, thus evaluating for anemia and possible deficiencies in oxygen - carrying capacity . Additionally, sickle cell disease, polycythemia, and thrombocytosis increase the risk for stroke.
7-In select patients with possible hypercoagulable states, protein C, protein S, antithrombin III, and Factor V Leiden testing may be required . These blood abnormalities mainly contribute to venous thrombosis but may be relevant in patients with cardiac shunts or cerebral venous thromboses
8-The anticardiolipin antibody and the lupus inhibitor, both antiphospholipid antibodies, correlate with arterial stroke, as well as with deep venous thrombosis, pulmonary embolism, myocardial infarction, and miscarriage
A dense MCA sign suggests a clot in the MCA . These patients are at risk for significant hemispheric strokes . Some authorities believe that these patients may benefit most from aggressive thrombolytic therapy, including intra - arterial therapies, but this has not been specifically proven in double - blind randomized trials .
Diffusion - weighted MRI ( DW - MRI ) can detect areas of ischemic brain injury earlier in the evolution of ischemia than standard T1 / T2-weighted MRI images or CT scan by detecting changes in water molecule mobility
Perfusion-weighted MRI ( PW - MRI ) uses injected contrast material to demonstrate areas of decreased perfusion .
These sequences in combination with DW - MRI yields areas of diffusion - weighted imaging / perfusion - weighted imaging ( DW - MRI / PW - MRI ) mismatch, theoretically identifying potentially salvageable tissues
ECG : Stroke and cardiovascular disease share many risk factors . ECG may demonstrate cardiac arrhythmias, such as atrial fibrillation, or may indicate acute ischemia . All patients with stroke should have an ECG as part of their initial evaluation
Chest radiography should be performed when clinically indicated
We should decide from the history, duration of onset and clinical presentation wither the case is anterior circulation (contralateral hemiparesis, dysphasia, apraxia, agnosia, preserved consciousness and visual field defect) or posterior circulation (vertigo, ataxia, dysphagia, diplopia, disturbed level of consciuosness, crossed hemiparesis and bilateral presentation) because if we received the patient within 160mins or less and there is no contraindications for thrombolytic therapy we decide this line of treatment accordingly.
Sodium nitroprusside 0.5 mcg / kg / min; may reduce approximately 10-20% SBP >220 or DBP 121-140 mm Hg or MAP >130 mm Hg
Labetalol 10-20 mg IVP over 1-2 min; may repeat and double every 10 min up to maximum dose of 150 mg or nicardipine 5 mg / h IV infusion and titrate SBP< 220 mm Hg or DBP 105-120 mm Hg or MAP <130 mm Hg Antihypertensive therapy indicated only if AMI, aortic dissection, severe CHF, or hypertensive encephalopathy present