Acute Ischemic Stroke : Diagnosis & Treatment

Acute Ischemic Stroke, also known as cerebrovascular accident, is an acute compromise of the cerebral perfusion or vasculature.1 Essentially, it is a condition that affects the arteries leading to and within the brain. This condition is the fifth leading cause of death in the United States and is considered the leading cause of disability. The incidence of stroke is roughly 800,000 people annually. In the past decade, the incidence of stroke has declined, but the related morbidity has increased.

A stroke can be classified into three main categories: ischemic, hemorrhagic, or transient ischemic attack. A hemorrhagic stroke is when a blood vessel within the brain ruptures and prevents adequate blood flow to the brain. A transient ischemic attack is considered a “mini stroke” and is caused by a temporary clot in the brain vasculature. An ischemic stroke, which is what will be discussed in this article, is caused by a clot complicating the flow of blood to the brain. Approximately 85% of strokes that occur are ischemic, with the rest being hemorrhagic.

The etiology of an acute ischemic stroke is due to either a thrombotic or embolic event that interrupts normal blood flow to the brain.2 This ultimately leads to ischemia, or lack of oxygen, to tissues of the brain. The pathophysiology behind this condition is the Na+/K+/ATPase pumps fail due to the poor production of adenosine triphosphate (ATP) and failure of aerobic mechanisms. The resulting ischemia causes cell hypoxia and depolarization. This causes an increase of calcium influx into cells, elevated lactic acid, acidosis, and free radicals. Eventually cell death occurs, thus, increasing glutamate which leads to a cascade of damaging chemicals.1

Clinical Presentation

 The American Stroke Association has suggested the acronym ACT FAST to recognize early symptoms of stroke in an individual. This includes:

  • F (Face) = a droop or an uneven smile on an individual’s face
  • A (Arms) = arm numbness or weakness and can examined by asking individual to raise their arms
  • S (Speech) = slurred speech or difficulty understanding speech
  • T (Time) = if any of the above symptoms are present without a reasonable cause, even if transient, it is time to seek emergency attention

This acronym is extremely helpful for both clinicians and caregivers to suspect if an individual is experiencing an acute ischemic stroke. Additional symptoms that an individual may present with include sudden numbness, confusion, trouble seeing or walking, or severe headache. Most of the above symptoms have an abrupt onset without an associated cause. Risk factors for developing an acute ischemic stroke include gender (female), advanced age, hyperlipidemia, hyperglycemia, cardiac arrhythmias, hypertension, smoking, obesity, drug use, and atherosclerotic disease.1,2 Common complications that arise from the disease can either cause temporary or permanent disabilities. These include loss of muscle movement, difficulty talking or swallowing, memory loss or thinking difficulties, emotional issues or depression, pain, and changes in behavior. Stroke patients can also be at an increased risk for brain edema, pneumonia, seizures, urinary tract infection, pressure sores, deep vein thrombosis, pulmonary embolism, anxiety, and recurrent stroke. It is extremely vital to identify and treat this condition with haste in order to reduce morbidity and mortality of the patient.1,2

Diagnosis

 Time is essential when an individual is being evaluated for a possible ischemic stroke, so things tend to move very quickly. An initial evaluation of the patient’s airway, breathing, circulation, and vital signs is needed to fully assess the condition of the patient. A fingerstick glucose check should be performed in order to rule out hypoglycemia as a cause of neurological abnormalities. A CT head or MRI is highly recommended within 20 min of patient presentation. This will help rule out a hemorrhagic stroke as the cause and help rule in the diagnosis of major or minor ischemic stroke.1,2

Other diagnostic tests include an electrocardiogram (ECG), troponin, complete blood count, electrolytes, blood urea nitrogen (BUN), creatinine, and coagulation factors. An ECG and troponin are necessary because stroke is often associated with coronary artery disease. A complete blood count can evaluate the possibility of infection or the presence of anemia. Electrolytes need to be drawn because they will need to be corrected to prevent further morbidity. BUN and creatinine need to be monitored due to the risk of contrast-induced kidney damage from a CT scan. Coagulation factors, which include INR, PTT, and PT, need to be evaluated because elevated levels may suggest hemorrhagic stroke as the underlying cause rather than ischemic stroke. To get proper diagnosis, then chat with doctor online today by visiting our website: https://justhealthexperts.com/

Treatment

 Patients with acute ischemic stroke who meet the specific criteria for Alteplase and do not have any contraindications should receive IV Alteplase. This medication is a fibrinolytic and works by dissolving the blood clot causing the ischemic stroke, thus, restoring blood flow to the brain and potentially preventing additional brain cells from dying. This medication can only be given within 4.5 hours of stroke onset (preferably 3 hours) and the dose is 0.9 mg/kg, with a max dose of 90 mg. The first 10% of the dose is given over the first minute, while the remainder is given over the next 60 minutes. Patients are excluded from receiving Alteplase if they present between 3 and 4.5 hours and are either over the age of 80, have severe stroke (NIHSS>25), history of diabetes prior to stroke, or taking an oral anticoagulant. Other contraindications to alteplase at any time frame within 4.5 hours include:

  • Severe head trauma or ischemic stroke within 3 months
  • Current severe uncontrolled hypertension (>185/110 mmHg)
  • Current intracranial or subarachnoid hemorrhage
  • Unclear time of symptom onset
  • Active internal bleed
  • Cranial or spinal surgery within 3 months
  • GI malignancy or bleed within 21 days
  • Direct thrombin inhibitors or direct factor Xa inhibitors
  • Coagulopathy
  • Received LMWH within 24 hours
  • Infective endocarditis
  • Glycoprotein IIb/IIIa receptor inhibitors

All patients, even individuals treated with Alteplase, should be considered for mechanical thrombectomy with a stent retriever in patients over 18 years of age. The indications for this procedure include minimal pre-stroke disability, causative occlusion of the internal carotid artery or proximal MCANIHSS of >6, reassuring non-contrast head CT, and if the patient can be treated within 6 hours of last known normal. Aspirin should be given to all individuals within 24-48 hours. The addition of another antiplatelet agent is still unclear and should be a patient specific decision. The POINT trial demonstrated that the combination of clopidogrel with aspirin had a lower risk of major ischemic events but a higher risk of major hemorrhage at 90 days, compared to those who received aspirin alone.3 If patients have minimal or no bleed risk, they may receive more benefit of dual antiplatelet therapy than those with an increased bleed risk. The benefits and risks need to be weighed in order to make the most appropriate clinical decision.

Complications of the underlying acute ischemic stroke will also need to be addressed. For example, anti-seizure medications, such as Keppra, will need to be given to patients who are or at increased risk of developing seizures. Also, if cerebral edema is present mannitol, which is an osmotic diuretic, can be given to help correct this condition. Blood glucose, DVT prophylaxis, addition of high intensity statin therapy, and patient temperature will need to be evaluated in order to reduce additional morbidity and mortality.  To learn more about nervous support related supplements, kindly link on this link: natural approaches to nervous system support 

References 

  1. Khaku AS, Tadi P. Cerebrovascular Disease (Stroke) [Updated 2020 Mar 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430927/
  2. Hui C, Tadi P, Patti L. Ischemic Stroke. [Updated 2020 Feb 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK499997/
  3. Johnston SC, Easton JD, Farrant M, et al. Clopidogrel and Aspirin in Acute Ischemic Stroke and High-Risk TIA. N Engl J Med. 2018;379(3):215‐225. doi:10.1056/NEJMoa1800410

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