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Stroke is the commonest cause of death in developed countries. Hypertension is the most treatable risk factor. Thromboembolic infarction (80%), cerebral and cerebellar haemorrhage (10%) and subarachnoid haemorrhage (about 5%) are the major cerebrovascular problems.

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Ischemic stroke usually results when an artery to the brain is blocked, often by a blood clot or a fatty deposit due to atherosclerosis

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Stroke is defined as the clinical syndrome of rapid onset of cerebral deficit (usually focal) lasting more than 24 hours or leading to death, with no apparent cause other than a vascular one. Completed stroke means the deficit has become maximal, usually within 6 hours. Stroke-in-evolution describes progression during the first 24 hours. Minor stroke. Patients recover without significant deficit, usually within a week. Transient ischemic attack (TIA). This means a focal deficit, such as a weak limb, aphasia or loss of vision lasting from a few seconds to 24 hours. There is complete recovery. The attack is usually sudden.

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An ischemic stroke is death of an area of brain tissue (cerebral infarction) resulting from an inadequate supply of blood and oxygen to the brain due to blockage of an artery

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Causes By forming in and blocking an artery:An atheroma in the wall of an artery may continue to accumulate fatty material and become large enough to block the artery By traveling from another artery to an artery in the brain: A piece of an atheroma or a blood clot in the wall of an artery can break off and travel through (the bloodstream (becoming an embolus

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By traveling from the heart to the brain: Blood clots may form in the heart or on a heart valve, particularly artificial valves and valves that have been damaged by infection of the heart's lining (endocarditis).

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Several conditions besides rupture of an atheroma can trigger or promote the formation of blood clots, increasing the risk of blockage by a blood clot. They include the following Blood disorders: Some disorders, such as an excess of red blood cells (polycythemia), antiphospholipid syndrome, and a high homocysteine level in the blood (hyperhomocysteinemia), make blood more likely to clot. In children, sickle cell disease can cause ischemic stroke

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Oral contraceptives: Taking oral contraceptives, particularly those with a high estrogen dose, increases the risk of blood clots

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Lacunar infarction is another cause of ischemic stroke. In lacunar infarction, one of the small arteries deep in the brain becomes blocked when part of its wall deteriorates and is replaced by a mixture of fat and connective tissuea disorder called lipohyalinosis.

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Blood clots in a brain artery do not always cause a stroke. If the clot breaks up spontaneously within less than 15 to 30 minutes, brain cells do not die and people's symptoms resolve. Such cases are called a transient ischemic attack

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Risk factors: The major risk factors for ischemic stroke Atherosclerosis (narrowing or blockage of arteries by patchy deposits of fatty material in the walls of arteries) High cholesterol levels High blood pressure Diabetes Smoking

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Other risk factors include Having relatives who have had a stroke Consuming too much alcohol Using cocaine or amphetamines Having an abnormal heart rhythm called atrial fibrillation Having another heart disorder, such as a heart attack or infective endocarditis (infection of the heart's lining) Having inflamed blood vessels (vasculitis) Being overweight, particularly if the excess weight is around the abdomen Getting too little physical activity Eating an unhealthy diet (such as one high in saturated fats, trans fats, and calories) Having a clotting disorder

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Determining the Location Large Vessel: Look for cortical signs Small Vessel: No cortical signs on exam Posterior Circulation: Crossed signs Cranial nerve findings Watershed: Look at watershed and borderzone areas Hypo-perfusion

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Stroke Symptoms Sudden numbness or weakness of face, arm or leg, especially on one side of the body Sudden confusion, trouble understanding or speaking Sudden trouble seeing in one or both eyes Sudden trouble walking, dizziness, loss of balance or coordination Sudden severe headache with no known cause

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Other Symptoms Sudden nausea, fever and vomiting, distinguished from a viral illness by rapid onset (minutes or hours vs. days) Brief loss of consciousness or period of decreased consciousness (fainting, confusion, convulsions or coma)

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Lacunar Stroke Syndromes Well-defined syndromes Pure motor hemiparesis (with dysarthria) Pure sensory stroke (loss or paresthesias) Dysarthria-clumsy hand (with contralateral face and tongue weakness) Ataxia-hemiparesis (contralateral face and leg weakness) Isolated motor-sensory stroke

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Large Vessel Stroke Syndromes MCA: Arm>leg weakness LMCA cognitive: Aphasia RMCA cognitive: Neglect,, topographical difficulty, apraxia, constructional impairment ACA: Leg>arm weakness, grasp Cognitive: muteness, perseveration, abulia, disinhibition PCA: Hemianopia Cognitive: memory loss/confusion, alexia Cerebellum: Ipsilateral ataxia

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Brainstem Stroke Syndromes Usually a combination of cranial nerve abnormalities, and crossed motor/sensory findings such as: Double vision Facial numbness and/or weakness Slurred speech Difficulty swallowing Ataxia Vertigo Nausea and vomiting Hoarseness

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Watershed: Look for the watershed pattern Think about reasons of hypo-perfusion Hypotension Stenosed vessel, etc

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Diagnosis Doctors can usually diagnose an ischemic stroke based on the history of events and results of a physical examination Computed tomography (CT) is usually done first CT helps distinguish an ischemic stroke from a hemorrhagic stroke, a brain tumor, an abscess, and other structural abnormalities

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Imaging CT scan Non- contrast CTH remains the gold standard as it is superior for showing IVH and ICH CT with contrast may help identify aneurysms, AVMs, or tumors but is not required to determine whether or not the patient is a tPa candidate

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MRI Superior for showing underlying structural lesion

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If available, diffusion-weighted magnetic resonance imaging (MRI), which can detect ischemic strokes within minutes of their start, may be done next Electrocardiography (ECG) to look for abnormal heart rhythms Imaging testscolor Doppler ultrasonography, magnetic resonance angiography, CT angiography, or cerebral (standard) angiographyto determine whether arteries, especially the internal carotid arteries, are blocked or narrowed

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Blood tests to check for anemia, polycythemia, blood clotting disorders, vasculitis, and some infections (such as heart valve infections and syphilis) and for risk factors such as high cholesterol levels or diabetes

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Treatment The first priority is to restore the person's breathing, heart rate, blood pressure (if low), and temperature to normal. An intravenous line is inserted to provide drugs and fluids when needed doctors do not immediately treat high blood pressure unless it is very high (over 220/120 mm Hg) because when arteries are narrowed, blood pressure must be higher than normal to push enough blood through them to the brain.

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Management Most likely related to decreased level of consciousness (LOC), dysarthria, dysphagia GCS < 8 - INTUBATE Avoid Hyperventilation or Hypoventilation NPO until swallow assessment completed- high aspiration risk Begin mobilization as soon as clinically safe

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very high blood pressure can injure the heart, kidneys, and eyes and must be lowered If a stroke is very severe, drugs such as mannitol may be given to reduce swelling and the increased pressure in the brain

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Hyperthermia Treat fevers! Evidence shows that fevers > 37.5 C that persists for > 24 hrs correlates with ventricular extension and is found in 83% of patients with poor outcomes

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BP Management The goal is to maintain cerebral perfusion!! CPP = MAP ICP (needs to be at least 70) Higher BP goals with Ischemic stroke Lower BP goals with Hemorrhagic stroke (avoid hemorrhagic expansion, especially in AVMs and aneurysms)

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BP increase is due to arterial occlusion (i.e., an effort to perfuse penumbra) Failure to recanalize (w/ or w/o thrombolytic therapy) results in high BP and poor neuro outcomes Lowering BP starves penumbra, worsens outcomes

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Supportive Therapy Glucose Management Infarction size and edema increase with acute and chronic hyperglycemia Hyperglycemia is an independent risk factor for hemorrhage when stroke is treated with t-PA Antiepileptic Drugs Seizures are common after hemorrhagic CVAs ICH related seizures are generally non-convulsive and are associated to with higher NIHSS scores, a midline shift, and tend to predict poorer outcomes

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Thrombolytic (fibrinolytic) drugs In certain circumstances, a drug called tissue plasminogen activator (tPA) is given intravenously to break up clots and help restore blood flow to the brain Before tPA is given, CT is done to rule out bleeding in the brain To be effective and safe, tPA, given intravenously, must be started within 3 hours of the beginning of an ischemic stroke

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Intravenous rTPA IV thrombolytic therapy remains the cornerstone of evidence-based acute ischemic stroke therapy (Class I; level A) IV rt-PA is efficacious and cost-effective for patients with acute ischemic stroke treated within 3 hours of symptom onset 6.6% complication of symptomatic intracranial hemorrhage (sICH)

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In patients with acute ischemic stroke in whom treatment can be initiated within 3 h of symptom onset, we recommend IV recombinant tissue plasminogen activator (r-tPA) over no IV r-tPA (Grade 1A).

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In patients with acute ischemic stroke in whom treatment can be initiated within 4.5 h but not within 3 h of symptom onset, we suggest IV r-tPA over no IV r-tPA (Grade 2C).

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Inclusion criteria Diagnosis of AIS causing measurable neurological deficit Onset of symptoms < 3hours before beginning treatment Age >18 or older

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Exclusion Criteria Significant head trauma or prior stroke in the last 3 months Symptoms suggest SAH Arterial puncture in non compressible site 185 or DBP> 110 mm Hg) Active internal bleeding Platelet count 15 secs Current use of Direct Thrombin inhibitors or factor Xa inhibitors Blood glucose concentration 1/3 of cerebral hemisphere)

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RELATIVE EXCLUSION CRITERIA CONSIDER RISK TO BENEFIT OF IVrTPA ADMINSTRATION CAREFULLY IF ANY OF THESE RELATIVE CONTRAINDICATIONS EXISTS: MINOR OR RAPIDLY IMPROVING SYMPTOMS SEIZURE AT ONSET WITH POST ICTAL IMPAIRMENTS MAJOR SURGERY OR SERIOUS TRAUMA