Enawgaw Mehari, M.D.
Founder and CEO, p2p Inc.
Morehead, KY, USA
Why is stroke a medical emergency? Both ischemic stroke and hemorrhagic stroke are medical emergency, because in case of ischemic stroke patients can benefit from intravenous thrombolysis (IVT) and mechanical thrombectomy if they present to the emergency department within the recommended time frame, 3 hours of onset. Hemorrhagic stroke is also an emergency, because it is recommended to lower blood pressure rapidly, to treat coagulation disorders, and if warranted to do surgery. Time is crucial to save the brain. The typical clinical presentation of a stroke consists of a sudden focal neurological deficit with maximum intensity at onset, such as aphasia, hemiplegia, or hemianopia. There are also other medical disorders which can present with similar clinical presentations, such as false positives and called “stroke mimics”.
Ischemic stroke is caused by occlusion or severe stenosis of a cerebral artery due to embolus or thrombosis resulting in reduced cerebral blood flow and impaired delivery of oxygen and glucose to the tissue supplied by that artery. The normal cerebral blood flow rate is 50 to 55 ml/100 gm/min. When this falls to 18 ml/100 mg/min neuronal electrical function fails. When it goes below 8 ml/100mg /min, cellular energy metabolism fails resulting to cell death. In general terms, stroke is therefore a reduction of perfusion to the brain. Transient ischemic attack (TIA) is a transient neurologic deficit of vascular origin, mostly lasting only 10 to 20 minutes. It is equivalent to unstable angina and should be treated aggressively. The term mini stroke is misleading as it may suggest the problem is less severe than stroke. They can have also a recurrent episode and therefore it is imperative to expedite the work up to avoid potential stroke.
The management of treatable risk factors and common mechanisms of brain ischemia is important for reducing the risk of ischemic stroke. Generally, a head computed tomographic (CT) scan is obtained immediately to rule out intracranial hemorrhage from ischemic stroke. The only therapy for restoring blood flow for which there is strong evidence of clinical benefit is intravenous (IV) recombinant tissue plasminogen activator (rt-PA) given within 3 hours of onset. The major risk of this intervention is symptomatic intracranial hemorrhage, which occurs in about 6% of patients who receive IV rt- pa according to the established guidelines. The major modifiable risk factors for ischemic stroke include hypertension, diabetes mellitus, smoking, dyslipidemia, physical inactivity, atrial fibrillation and carotid artery stenosis. The risk of stroke is particularly increased in patients with two or more risk factors. TIA should be treated with all available risk reduction strategies. Currently, viable strategies include blood pressure reduction, antithrombotic therapy, statin therapy, and life style modification. Selected patients with symptomatic cervical internal carotid artery disease may benefit revascularization. There is now a notion that by effectively modifying risk factors for stroke and heart attack, death can be optional.
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