Ischaemic Stroke

Ischemic Stroke Synonyms : brain attack, cerebrovascular accident, It is a sudden loss of function resulting from disruption of the blood supply to a part of the brain. The event is the result of long-standing cerebrovascular disease.

Ischaemic strokes divided into five different types according their cause : large artery thrombosis : atherosclerotic plaques in the large blood vessels of the brain. Thrombus formation and occlusion at the site of the atherosclerosis – ischaemia and infarction small penetrating artery thrombosis : one or more vessels are affectedmost common. Also called lacunar strokes because of the cavity that is created when the infarcted brain tissue disintegrates cardiogenic embolic stroke : associated with cardiac arrhythmias : atrial fibrillation. Emboli may be prevented by the use of anticoagulation therapy cryptogenic and others : no known cause

Major Types of Stroke and Their Causes CLASSIFICATION CAUSES Ischemic large artery thrombosis small penetrating artery . thrombosis cardiogenic embolic cryptogenic (no known cause) others Hemorrhagic intracerebral haemorrhage Subarachnoid haemorrhage cerebral aneurysm arteriovenous malformation

Pathophysiology In ischemic brain attack : disruption of blood flow due to obstruction of a blood vessel  ischaemic cascade Early in the cascade, an area of low cerebral blood flow, referred to as the Penumbra region exists around the area of infarction Timely intervention may prevent infarction from spreading into the penumbra region

Clinical Manifestations Neurological deficits Numbness or weakness of the face, arm, or leg, especially on one side of the body Confusion or change in mental status Trouble speaking or understanding speech Visual disturbances Difficulty walking, dizziness, or loss of balance or coordination Sudden severe headache Motor, sensory, cranial nerve, cognitive, and other functions may be disrupted

Motor loss : hemiplegia or hemiparesis Communication loss : dysarthria, dysphasia or aphasia expressive or receptive or global (mixed) aphasia Apraxia : inability to perform a previously learned action - combing using fork Perceptual disturbances : homonymous hemianopsia – same side as paralysis Sensory loss : touch sensation; proprioception, visual, tactile, and auditory stimuli Cognitive impairment and psychological effects: frontal lobe damage : learning capacit, memory, or other higher cortical intellectual functions may be impaired. Memory affected. Inattention +, lack of motivation, depression, emotional lability, hostility, frustation, resentment, lack of cooperation

Assessment And Diagnostic Findings History and neurological examination Transient ischaemic attack Reversible ischemic neurologic deficit Stroke in evolution Completed stroke Initially non-contrast CT brain – ischaemic or haemorrhagic ECG, carotid ultrasound cerebral angiography, transcranial doppler flow studies, transthoracicor transesophageal echocardiography, manetic resonance imaging of the brain or neck, xenon CT, single photon emission CT. , digital subtraction angiography for carotid artery

An ischemic stroke occurs when an artery in the brain becomes blocked.

A major ischemic stroke

Ischemic Stroke

Haemorrhagic stroke

CT angiogram of the neck with arrow pointing to blockage in the internal carotid artery)

Carotid endarterectomy

Carotid stenting

Ischemic stroke Acute care: Thrombolysis ("clot busting") is sometimes used to dissolve the clot causing an acute stroked. This involves administering a medication into the blood stream (either intravenous or directly into the clot within an artery) within hours of the stroke. Studies indicate that after three hours of symptom onset the damage to the brain is irreversible, and that thrombolysis provides no benefit. Long term care: This type of stroke is usually caused by hypoperfusion as a result of narrowing or occlusion of the arteries in the neck which supply blood to the brain. Often, this can be surgically corrected by a procedure called carotid endarterectomy, which cleans out the involved

Prevention Treat hypertension Treat hyperglycemia Stop smoking Reduce high cholesterol Reduce obsity Low cholesterol low fat diet exercise

Medical treatment AF : warfarin or aspirin or clopidogrel (antiplatelet regimen) Administration of t-PA – loading dose and then infusion Low molecular weight heparin – dalteparin If ICT is increased – mannitol, maintaining PaCO2 within the range of 30 – 35 mmHg. , positioning to avoid hypoxia Elevation of head end Intubation if needed Bp within 180/100 mmHg

Nursing interventions Improving and preventing joint deformities Preventing shoulder adduction Positioning the hand and fingers Changing positions Establishing an exercising program Preparing for ambulation Preventing shoulder pain Enhancing self care Managing dyphagia Managing tube feeding

Nursing interventions Attaining bladder and bowel control Improving thought processes Improving communication Maintaining skin integrity Improving family coping Helping the patient cope with sexual dysfunction Teaching self care and continuing care

Glossary Agnosia : failure to recognize familiar objects perceived by the senses Aneurysm : a weakening or bulge in an arterial wall Aphasia : inability to express oneself or to understand language Apraxia : inability to perform previously learned purposeful motor acts on a voluntary basis Ataxia : impaired ability to coordinate movement, often seen as a staggering gait or postural imbalance Dysarthria : difficulty in articulation due to neurologic causes Expressive aphasia : inability to express oneself often associated with damage to th left frontal lobe area Hemianopsia : blindness of half of the field of vision on one or both eyes