By: Nicole Bass, Kara Forwith, Olivia Martin
What is an Ischemic Stroke?
Cerebral Thrombosis- refers to a thrombus, also known as a blood clot, that develops at the clogged part of the vessel.
Cerebral Embolism- refers generally to a blood clot that forms at another location in the circulatory system, usually the heart and large arteries of the upper chest and neck. A portion of the blood clot breaks loose, enters the bloodstream and travels through the brain's blood vessels until it reaches vessels too small to let it pass. A second important cause of embolism is an irregular heartbeat, also known as atrial fibrillation. It creates conditions where clots can form in the heart, dislodge and travel to the brain. Silent cerebral infarction, also known as a “silent stroke,” is a brain injury likely caused by a blood clot interrupting blood flow in the brain. It’s a risk factor for future strokes which could lead to progressive brain damage due to these strokes.
Ischemic Strokes are the most common types of strokes and account for 87% of all stroke cases (Mayo Clinic, 2015.)
Pathophysiolgy of Ischemic Strokes
Who is at Risk for Ischemic Strokes?
- History of Transient Ischemic Stroke
- Heart Disease
- Family History of Cerebrovascular Disease
- Alcohol Use
- Cardiac Arrhythmias, such as Atrial Fibrillation
- Diabetes Mellitus
- Use of Hormonal Contraceptives in Conjunction with Smoking and Alcohol Use
- High Red Blood Cell Count
- High Serum Triglyceride Levels
- Elevated Cholesterol and Triglycerides
- Use of Illegal Drugs
Tests and Procedures for Ischemic Strokes
- Anticardiolipin Antibodies, Antiphospholipid, Factor V Mutation, Antithrombin III, Protein S, and Protein C- these lab results may show increase for thrombotic risk.
- Coagulation Studies- to help determine eligibility for treatment.
- Magnetic Resonance Imaging and Angiography- to help determine the location and size of the lesion.
- Cerebral Angiography- helps to detail the disruption of cerebral circulation and is the test of choice for examining the entire cerebral blood flow.
- Computed Tomography Scanning (brain)- can help detect hemorrhage or structural abnormalities.
- Positron Emission Tomography- can provide data on cerebral metabolism and cerebral blood flow changes.
- Carotid Duplex Scanning- helps identify the cause of the stroke and helps evaluate for carotid stenosis.
- Lumbar Puncture- rules out meningitis and subarachnoid hemorrhage if computed tomography scanning is negative.
- Transcranial Doppler Studies- evaluate the velocity of blood flow and identify the location and degree of arterial occlusion.
- Carotid Artery Duplex Scanning- measures flow through the carotid arteries, identifying reduced blood flow.
- Two-Dimensional Echocardiography- evaluates the heart for dysfunction; transthoracic and transesophageal echocardiography identify a possible cardiac origin of the stroke.
- Cerebral Blood Flow Studies- measure blood flow to the brain.
- Electrocardiography- evaluates electrical activity in cortical infarction.
Clinical Manifestations of Ischemic Strokes
- With stroke in the left hemisphere, signs and symptoms on the right side
- With stroke in the right hemisphere, signs and symptoms on the left side
- With stroke that causes cranial nerve damage, signs and symptoms on the same side
- Change in level of consciousness
- With a conscious patient, anxiety along with communication and mobility difficulties
- Urinary incontinence
- Loss of voluntary muscle control
- Hemiparesis or hemiplegia on one side of the body
- Facial droop
- Monocular or binocular blindness, blurred vision, or visual field deficits
- Decreased deep-tendon reflexes
- Hemianopsia on the affected side of the body
- With left-sided hemiplegia, problems with visual-spatial relations
- Sensory losses
- Dysarthria or aphasia
- Ataxia, vertigo, nystagmus
Treatments of an Ischemic Stroke
- When the cause isn't hemorrhagic, Tissue Plasminogen Activator (Activase)- emergency care within 3 to 4½ hours of symptom onset
- Enteric-coated aspirin- with careful monitoring of patient
- Anticonvulsants- such as diazepam (Valium) and lorazepam (Ativan)
- Mannitol (Aridol)- to reduce increased ICP
- Stool softener- such as docusate sodium (Colace); to help a patient not become constipated
- Anticoagulants- such as heparin for deep vein prophylaxis, warfarin (Coumadin) or dabigatran etexilate mesylate (Pradaxa) to reduce the risk of atrial fibrillation (a major risk factor for stroke)
- Antiplatelets- such as aspirin or dipyridamole (Persantine)
- Lipid-lowering agents- such as atorvastatin (Lipitor) or pravastatin (Pravachol)- to help maintain cholesterol and triglycerides
- Antihypertensives- such as labetalol hydrochloride (Normodyne), enalapril (Vasotec), niCARdipine hydrochloride (Cardene), and sodium nitroprusside (Nipride)- to help maintain blood pressure.
- Insulin to maintain blood sugar between 80 and 140 mg/dL
- Extracranial-intracranial bypass
- Ventricular shunts
Medications and Surgery can be an immediate fix but patients may need more long term care such as controlling diet, physical therapy, and occupational therapy.
Swanson, J. (2015).
Ischemic Strokes. Retrieved November 30, 2015, from http://www.mayoclinic.org/diseases-conditions/stroke/home/ovc-20117264
Unbound Medicine, Inc. (2014). Nursing Central (1.22.) [Mobile application software]. Retrieved from < https://itunes.apple.com/us/app/nursing-central/id300420397?mt=8>