Cerebral Vascular Disease

1. Cerebral Vascular Disease Vicki Gamez

2. Cerebrovascular accidents (CVA) are classified as either ischemic or hemorrhagic. The extent of CVA depends on how quickly onset occurred, the size of lesion/hemorrhage, the presence of collateral circulation, and how quickly the patient is treated. A CVA can impair many body functions and the functions that are affected depend directly to the artery that is involved and the areas of the brain that blood is supplied to from that artery.

3. Ischemic CVA • Results from inadequate blood flow to the brain due to a partial or complete occlusion of the artery. • Responsible for 80% of the CVAs. • Two types: Thrombotic and Embolic.

4. Thrombotic Stroke • Occurs from a formation of blood clot, which causes damage to a blood vessel. • This is the most common type of stroke and accounts for about 60% of strokes. The blood vessel becomes narrowed and occluded. • Thrombotic strokes frequently occur due to narrowed blood vessels by atherosclerotic plaques. • Many of these patients previously suffered a TIA.

5. Embolic Stroke • Occurs when embolus (blood, fat, air) occludes the cerebral artery causing an infarction and edema of local area. • Embolic stroke is responsible for 24% of strokes. • The majority of embolic strokes results when a plaque is broken from the endocardium and enters in circulation. The embolus travels to cerebral circulation and becomes lodged in a narrow vessel or at the bifurcation of vessels. • The patient will have a rapid onset of symptoms and prognosis depends on amount of cerebral tissue that is deprived of it blood supply. This occurs frequently with patients who have underlying cardiac condition such as atrial fibrillation, myocardial infarction, and atrial septal defects

6. Hemorrhagic CVA • Occurs due to bleeding into the brain tissue or into the subarachnoid space or ventricles. • Hemorrhagic strokes account for 15% of all strokes. • Intracerbral hemorrhage (ICH) occurs due to a rupture of the vessel and prognosis is poor due to a mortality rate for 30 days is 40-80%. • The major cause of ICH include hypertension however other causes include vascular malformation, ruptured aneurysm, trauma, and brain tumors. Symptoms occur rapidly and depend on extent of bleeding.

7. Hemorrhagic CVA • Subarachnoid hemorrhages (SAH) occur due to bleeding between the arachnoid and pia matter membranes on surface of the brain. • These occur frequently due to rupture of cerebral aneurysm; however, arterivenous malformations, trauma, and illicit drugs can cause SAH. • Depending on the size and location of the bleed, patients may have warning signs; however, 35% or people with a rapid ruptured aneurysm die during the first episode of bleeding.

8. Signs and Symptoms • Change in mental status • Weakness/paralysis of one side • Change in vision or speech • Severe headache • Heart rate increase or decrease • Unequal pupils • Hypertension • Facial drooping /A new drift • Nausea and/or vomiting • New onset of seizures

9. Right Side vs. Left Side CVA

10. Diagnostic Tests • CT and CTA will indicate the size, location, and differentiate between ischemic and hemorrhagic stroke. If the stroke is ischemic and less than 3 hours old than CT will normal. • CTA will show for any intracranial or extracranial occlusive disease • MRI used to determine the extent of injury to the brain. • MRA will assess the vascular occlusive disease in the head or neck.

11. Cardiac Assessment and Blood Studies • Angiography will identify cervical and cerebrovascular occlusions, atherosclerotic plaques, and malformations of vessels. • Transcranial Doppler (TCD) measures the velocity of blood flow in the major cerebral arteries. TCD detects if there are microemboli and vasopasm • EKG and Holter assess for dysrhythmias that can be cause of ischemic CVA. • Transesophageal echocardiogram (TEE) allows visualization of size of heart, valvular abnormalities and possible source of thrombi. Contrast dye used frequently to evaluate if there is arterial or septal defect.

12. Treatment • Ischemic Stroke: Tissue plasminogen activator (tPA) if CT is normal & patient last seen at baseline within 3 hrs or Merci Retriever • Embolic Stroke: Treatmentof underlying cause • Hemorrhagic Stroke: Surgical decompression if indicated. Clipping, wrapping or coiling of aneurysm.

13. Collaborative Management • Document time of change or when patient was last time seen at baseline due to this can affect treatments such as tPA. • Contact stroke team/ physician and have patient ready for transport for imaging. Stroke team consists of a RN, neurologist, radiologist, and CT technician. • Place patient on oxygen to maintain SaO2>93%, head of bed at 30 degrees, and patient on NPO status to decrease risk of aspiration.

14. Obtain vital signs and finger stick, complete an EKG. In first phase of CVA, blood pressure is usually elevated and EKG can identify atrial fibrillation and other causes of CVA. An elevated BP is a protective response to maintain cerebral perfusion, however a BP >220 mmHg should be treated. Obtain a finger stick due to hypoglycemia can mimic signs and symptoms of CVA. Monitor temperature due to pyrexia in first 24 hrs after CVA is associated with greater neurological deficit and elevated temperatures in the first 72 hrs are associated with increased mortality. • Insert two large bore IVs and obtain labs. Labs to assess patient’s cholesterol, glucose, electrolytes, cardiac markers, and sedimentation rate to help determine cause of CVA. • Hold anticoagulation, sedatives, and narcotics until imaging has ruled out brain hemorrhage and not to mask any other neurological changes.

15. Case Study • The patient is a 68 y/o male who was found by his nurse with right side weakness, aphasic, and right gaze preference. The nurse initiated stroke protocol and contacted the physician. CT of the head showed an embolic left middle cerebral artery occlusion. The patient underwent an embolization.