Cerebrovascular Accident (CVA) mashehabat@just.edu.jo

Cerebrovascular Accident (CVA)

mashehabat@just.edu.jo

Definition

Ischemia is inadequate blood flow

Brain attack (Stroke) occurs when there is ischemia to a part of the brain that results in death of brain cells

Incidence

3rd Cause of death in US and Canada Statistics

2/3 in people >65 = in men and women Higher incidence and death rates

among African-Americans, Hispanics, Native-American, Asian Americans

Risk Factors

Non Modifiable Age Gender Race Heredity

Risk Factors

Modifiable Obesity HTN Smoking Heavy alcohol

consumption Hypercoagulability Hyperlipidemia

Asymptomatic carotid stenosis

Diabetes mellitus Heart disease,

atrial fibrillation Oral

contraceptives Physical inactivity Sickle cell disease

Review of Cerebral Circulation

Blood supply by arteries

Blood is supplied to the brain by two major pairs of arteries Internal carotid arteries Vertebral arteries

Blood supply by arteries

Carotid arteries branch to supply most of the Frontal, parietal, and temporal lobes Basal ganglia Part of the diencephalon

Thalamus Hypothalamus

Blood supply by arteries

Vertebral arteries join to form the basilar artery, which supply the Middle and lower temporal lobes Occipital lobes Cerebellum Brainstem Part of the diencephalon

“Brain Attack” means:

Blood flow to the brain is totally interrupted

Etiology

Atherosclerosis – Disease of the arteries; hardening and thickening of the arterial wall because of soft deposits of intraarterial fat and fibrin that harden over time.

Common sites for the development of Atherosclerosis

Transient Ischemic Attack (TIA)

Transient ischemic attack (TIA) is a temporary focal loss of neurologic function caused by ischemia

Most TIAs resolve within 3 hours TIAs are a warning sign of

progressive cerebrovascular disease

Types of Stroke

Strokes are classified based on the underlying pathophysiologic findings

Ischemic Hemorrhagic

Ischemic vs. Hemorrhagic

Ischemic Stroke

Ischemic strokes result from inadequate blood flow to the brain from partial or complete occlusion of an artery

85% of all strokes are ischemic strokes

Ischemic Stroke

Thrombotic or Embolic

Most patients with ischemic Most patients with ischemic stroke do not have a stroke do not have a decreased level of decreased level of consciousness in the first 24 consciousness in the first 24 hourshoursMay progress in the first 72 May progress in the first 72 hourshours

Thrombotic stroke

Thrombosis occurs in relation to injury to a blood vessel wall and formation of a blood clot

Result of thrombosis or narrowing of the blood vessel

Most common cause of stroke

Embolic stroke

Occur when an embolus lodges in and occludes a cerebral artery

Results in infarction and edema of the area supplied by the involved vessel

Second most common cause of stroke

Embolic stroke Majority of emboli originate in the

inside layer of the heart, with plaque breaking off from the endocardium and entering the circulation

Patient with an embolic stroke commonly has a rapid occurrence of severe clinical symptoms

Hemorrhagic Stroke

Account for approximately 15% of all strokes

Result from bleeding into the brain tissue itself or into the subarachnoid space or ventricles

Hemorrhagic Stroke Intracerebral hemorrhage

Bleeding within the brain caused by a rupture of a vessel

Hypertension is the most important cause

Hemorrhage commonly occurs during periods of activity

Hemorrhagic Stroke Intracerebral hemorrhage

Manifestations include neurologic deficits, headache, nausea, vomiting, decreased levels of consciousness, and hypertension

Hemorrhagic Stroke Subarachnoid hemorrhage

Occurs when there is intracranial bleeding into cerebrospinal fluid-filled space between the arachnoid and pia mater

Commonly caused by rupture of a cerebral aneurysm

Clinical Manifestations Affects many body functions

Motor activity Elimination Intellectual function Spatial-perceptual alterations Personality Affect Sensation Communication

Clinical Manifestations

Brain attack Term increasingly being used to

describe stroke and communicate urgency of recognizing stroke symptoms and treating their onset as a medical emergency

Clinical ManifestationsMotor Function

Most obvious effect of stroke Include impairment of

Mobility Respiratory function Swallowing and speech Gag reflex Self-care abilities

Clinical ManifestationsMotor Function

An initial period of flaccidity may last from days to several weeks and is related to nerve damage

Spasticity of the muscles follows the flaccid stage and is related to interruption of upper motor neuron influence

Clinical ManifestationsCommunication

Patient may experience aphasia when a stroke damages the dominant hemisphere of the brain Aphasia is a total loss of

comprehension and use of language

Diagnostic Studies

When symptoms of a stroke occur, diagnostic studies are done to Confirm that it is a stroke Identify the likely cause of the stroke

CT is the primary diagnostic test used after a stroke

Diagnostic Studies

Additional studies Complete blood count Platelets, prothrombin time, activated

partial thromboplastin time Electrolytes, blood glucose Renal and hepatic studies Lipid profile

Collaborative CarePrevention

Goals of stroke prevention include Health management for the well

individual Education and management of

modifiable risk factors to prevent a stroke

Collaborative CarePrevention

Antiplatelet drugs are usually the chosen treatment to prevent further stroke in patients who have had a TIA

Aspirin is the most frequently used antiplatelet drug

Collaborative CarePrevention

Surgical interventions for the patient with TIAs from carotid disease include Carotid endarterectomy Transluminal angioplasty Stenting Extracranial-intracranial bypass

Collaborative CareAcute Care

Interventions – Initial Ensure patient airway Remove dentures Perform pulse oximetry Maintain adequate oxygenation IV access with normal saline Maintain BP according to guidelines

Collaborative CareAcute Care

Interventions – Initial Remove clothing Obtain CT scan immediately Perform baseline laboratory tests Position head midline Elevate head of bed 30 degrees if no

symptoms of shock or injury

Collaborative CareAcute Care

Interventions – Ongoing Monitor vital signs and neurologic

status Level of consciousness Motor and sensory function Pupil size and reactivity O2 saturation Cardiac rhythm

Collaborative CareAcute Care

Recombinant tissue plasminogen activator (tPA) is used to Reestablish blood flow through a

blocked artery to prevent cell death in patients with acute onset of ischemic stroke symptoms

Collaborative CareAcute Care

Thrombolytic therapy given within 3 hours of the onset of symptoms ↓ disability But at the expense of ↑ in deaths

within the first 7 to 10 days and ↑ in intracranial hemorrhage

Collaborative CareAcute Care

Surgical interventions for stroke include immediate evacuation of Aneurysm-induced hematomas Cerebellar hematomas (>3 cm)

Collaborative CareRehabilitation Care

After the stroke has stabilized for 12-24 hours, collaborative care shifts from preserving life to lessening disability and attaining optimal functioning

Patient may be transferred to a rehabilitation unit