Cva

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Cerebrovascular Accident

CVA/STROKE

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Cerebrovascular Accidentis the rapidly developing loss of brain function(s) due to

disturbance in the blood supply to the brain. Results from ischemia to a part of the brain or

hemorrhage into the brain that results in death of brain cells. Third most common cause of death #1 leading cause of disability 25% with initial stroke die within 1 year50-75% will be functionally independent25% will live with permanent disability

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Cerebrovascular AccidentRisk Factors

Nonmodifiable:

Age – Occurrence doubles each decade >55 yearsRace – African AmericansHeredity – family history, prior transient ischemic attack, or prior stroke increases

risk

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Cerebrovascular AccidentRisk Factors

Controllable Risks High blood pressure DiabetesCigarette smoking High blood cholesterol ObesityHeart Disease Atrial fibrillation

Oral contraceptive use Physical inactivity Asymptomatic carotid stenosis

Hypercoagulability

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Cerebrovascular AccidentAnatomy of Cerebral Circulation

Blood Supply

Anterior: Carotid Arteries – middle & anterior cerebral arteriesfrontal, parietal, temporal lobes; basal ganglion; part of the diencephalon

(thalamus & hypothalamus)

Posterior: Vertebral Arteries – basilar arteryMid and lower temporary & occipital lobes, cerebellum, brainstem, & part

of the diencephalon

Circle of Willis – connects the anterior & posterior cerebral circulation

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Cerebrovascular AccidentAnatomy of Cerebral Circulation

Blood Supply

20% of cardiac output—750-1000ml/min

>30 second interruption– neurologic metabolism is altered; metabolism stops in 2 minutes; brain cell death < 5 mins.

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Cerebrovascular AccidentPathophysiology

Atherosclerosis: major cause of CVAThrombus formation & emboli development

Abnormal filtration of lipids in the intimal layer of the arterial wall

Plaque develops at locations of increased turbulence of blood – Bifurcations

Calcified plaques rupture or fissurePlatelets & fibrin adhere to the plaqueNarrowing or blockage of an artery by thrombus or emboli

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Cerebrovascular AccidentTransient Ischemic Attack

Temporary focal loss of neurologic function

Caused by ischemia of one of the vascular territories of the brainMicroemboli with temporary blockage of blood flow

Lasts less than 24 hrs – often less than 15 mins

Most resolve within 3 hours

Warning sign of progressive cerebrovascular disease

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Cerebrovascular AccidentClassifications

Based on underlying pathophysiologic findings

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Cerebrovascular AccidentClassifications

Ischemic StrokeThromboticEmboli

Hemorrhagic StrokeIntracerebral HemorrhageSubarachnoid HemorrhageAneurysmArterio venous malformation

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Cerebrovascular AccidentClassifications

Ischemic Stroke—inadequate blood flow to the brain from partial or complete occlusions of an artery--85% of all strokes– Extent of a stroke depends on:• Rapidity of onset• Size of the lesion• Presence of collateral circulation

– Symptoms may progress in the first 72 hours as infarction & cerebral edema increase

Types of Ischemic Stroke: Thrombotic Stroke Embolic Stroke

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Cerebrovascular AccidentIschemic – Thrombotic Stroke

Lumen of the blood vessels narrow – then becomes occluded – infarction

Associated with HTN and Diabetes Mellitus>60% of strokes50% are preceded by TIALacunar Stroke: development of cavity in place of

infarcted brain tissue – results in considerable deficits – motor hemiplegia, contralateral loss of sensation or motor ability

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Cerebrovascular AccidentThrombotic Stroke

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Cerebrovascular AccidentCommon Sites of Atherosclerosis

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Cerebrovascular AccidentIschemic – Embolic Stroke

Embolus lodges in and occludes a cerebral arteryResults in infarction & cerebral edema of the area

supplied by the vesselSecond most common cause of stroke – 24%Emboli originate mainly from endocardial layer of the

heart – atrial fibrillation, MI, infective endocarditis, valvular prostheses

Rapid occurrence with severe symptoms – body does not have time to develop collateral circulation

Any age groupRecurrence common if underlying cause not treated

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Cerebrovascular AccidentEmbolic Stroke

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Cerebrovascular AccidentHemorrhagic Stroke

Hemorrhagic Stroke15% of all strokesResult from bleeding into the brain tissue

itself IntracerebralSubarachnoid

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Cerebrovascular AccidentHemorrhage Stroke

Intracerebral Hemorrhage

Rupture of a vesselHypertension – most important causeOthers: vascular malformations, coagulation disorders,

anticoagulation, trauma, brain tumor, ruptured aneurysmsSudden onset of symptoms with progressionNeurological deficits, headache, nausea, vomiting, decreased

LOC, and hypertensionPrognosis: poor – 50% die within weeks20% functionally independent at 6 months

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Cerebrovascular AccidentHemorrhage Stroke

Intracerebral Hemorrhage

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Cerebrovascular AccidentHemorrhagic-Subarachnoid

Hemorrhagic Stroke–Subarachnoid Hemorrhage

Intracranial bleeding into the cerebrospinal fluid-filled space between the arachnoid and pia mater membranes on the surface of the brain

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Cerebrovascular Accident Hemorrhagic-Subarachnoid

Commonly caused by rupture of cerebral aneurysm (congenital or acquired)Saccular or berry – few to 20-30 mm in sizeMajority occur in the Circle of Willis

Other causes: Arteriovenous malformation (AVM), trauma, illicit drug abuse

Incidence: 6-16/100,000Increases with age and more common in women

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Cerebrovascular Accident Hemorrhagic-Subarachnoid

Cerebral AneurysmWarning Symptoms: sudden onset of a severe

headache – “worst headache of one’s life”

Change of LOC, Neurological deficits, nausea, vomiting, seizures, stiff neck

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Hemorrhagic-Subarachnoid Cerebral Aneurysm

Surgical Treatment:Clipping the aneurysm – prevents rebleedCoiling – platinum coil inserted into the lumen of the

aneurysm to occlude the sac

Postop: Vasospasm prevention – Calcium Channel Blockers

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Hemorrhagic-Subarachnoid Cerebral Aneurysm – Surgical Tx

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Hemorrhagic-Subarachnoid Cerebral Aneurysm – Coiling

Clinical manifestations

Neurologic deficits Depending on –• Location of the lesion (which vessel are

obstructed )• The size of the area of inadequate perfusion • The amount of collateral blood flow

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Motor loss

Stroke is a disease of upper motor neuron and results in loss of voluntary control over motor movements

- Upper motor neuron decussate - most common motor dysfunction is

hemiplegia due to lesion of the opposite side of the brain

- Hemiparesis also another sign -

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CommunicationAphasia/Dysphasia:-defect or loss of speech

- Receptive Aphasia :- sounds of speech nor its meaning can be understood – spoken & written

- Expressive Aphasia :- difficulty in speaking and writing

Dysarthria: Affects the mechanics of speech due to muscle control disturbances – pronunciation, and phonation

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Perceptual disturbance • Visual perceptual dysfunction -due to disturbances of the primary sensory

pathways between the eye and visual cortex Homonymous Hemianopia:-loss of half of the visual

field - may be temporary or permanent - the affected side of the vision corresponds to the paralyzed side of the body - pts head turns away from the affected side of his body

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Disturbance in Visual spatial r/ship

• Perceiving relationship of two or more objects in spatial areas

• Frequently seen in patients with left hemiplegia

• Pt may not able to dress him/herself b/se of his/her ability to match his clothing to his body parts

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Sensory losses

• Loss of proprioception :-inability to perceive position and motion of body parts

• Difficulty in interpreting visual ,tactile,and auditory stimuli

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AffectDifficulty controlling emotionsExaggerated or unpredictable emotional responseDepression / feelings regarding changed body

image and loss of function

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Intellectual FunctionMemory and judgment

Left-brain stroke: cautious in making judgmentsRight-brain stroke: impulsive & moves quickly to

decisionsDifficulties in learning new skills

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EliminationMost problems occur initially and are temporaryOne hemisphere stroke: prognosis is excellent for

normal bladder functionBowel elimination: motor control not a problem –

constipation associated with immobility, weak abdominal muscles, dehydration, diminished response to the defecation reflex

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Cerebrovascular AccidentClinical Manifestations

Right Brain – Left Brain Damage

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Homonymous Hemianopia

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Cerebrovascular AccidentTreatment Goals

PreventionDrug TherapySurgical TherapyRehabilitation

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Cerebrovascular AccidentTreatment Goals

Prevention – Health Maintenance Focus:Healthy dietWeight controlRegular exerciseNo smokingLimit alcohol consumptionRoute health assessmentControl of risk factors

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Cerebrovascular AccidentDiagnostic Studies

Done to confirm CVA and identify causePE: Neuro AssessmentCarotid doppler studies (ultrasound study)CT – primary – identifies size, location, differentiates

between ischemic and hemorrhagicMRI – greater specificity than CT

May not be able to be used on all patients (metal, claustrophobia)

Angiography: gold standard for imaging carotid arteries

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Cerebrovascular AccidentTreatment Goals

Drug Therapy – Thrombotic CVA – to reestablish blood flow through a blocked artery

Thrombolytic Drugs: tPA (tissue plasminogen activator) produce localized fibrinolysis by binding to the fibrin in the thrombi Plasminogen is converted to plasmin (fibrinolysin) Enzymatic action digests fibrin & fibrinogen Results is clot lysis

Administered within 3 hours of symptoms of ischemic CVA Confirmed DX with CT Patient anticoagulated

ASA, Calcium Channel Blockers

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Cerebrovascular AccidentTreatment Goals

Drug TherapyMeasures to prevent the development of a thrombus or

embolus for “At Risk” patients:

Antiplatelet AgentsAspirinPlavixCombination

Oral anticoagulation – Coumadin Treatment of choice for individuals with atrial fibrillation who have had

a TIA

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CVA - Treatment GoalsSurgical Treatment

Carotid endarterectomy – preventive – > 100,000/yearremoval of atheromatous lesions

Clipping, wrapping, coiling AneurysmEvacuation of aneurysm-induced hematomas larger

than 3 cm.Treatment of AV Malformations

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Carotid Endarterectomy

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Cerebrovascular AccidentNursing Diagnoses

Ineffective tissue perfusion r/t decreased cerebrovascular blood flow

Ineffective airway clearanceImpaired physical mobilityImpaired verbal communicationImpaired swallowingUnilateral neglect r/t visual field cut & sensory lossImpaired urinary eliminationSituational low self-esteem r/t actual or perceived loss of

function

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Cerebrovascular AccidentNursing Goals

Maintain stable or improved LOCAttain maximum physical functioningAttain maximum self-care activities & skillsMaintain stable body functionsMaximize communication abilitiesMaintain adequate nutritionAvoid complications of strokeMaintain effective personal & family coping

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Cerebrovascular AccidentWarning Signs of Stroke

Sudden weakness, paralysis, or numbness of the face, arm, or leg, especially on one side of the body

Sudden dimness or loss of vision in one or both eyes

Sudden loss of speech, confusion, or difficulty speaking or understanding speech

Unexplained sudden dizziness, unsteadiness, loss of balance, or coordination

Sudden severe headache

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Cerebrovascular AccidentAcute Phase

Nsg Action:Supportive Care

Respiratory – spans from intubation to breathing on ownMusculoskeletal -- Positioning – side-to-side; GU – Foley catheterSkin – preventive careMeds: anti platelet

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Cerebrovascular AccidentAcute Phase

Patient Education:

Clear explanations for all care/treatmentsFocus on improvements—regained abilitiesInclude family

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Cerebrovascular AccidentRehabilitation

Assess: Swallowing; Communication; Complications; motor and sensory function

Nsg Action: Coordinate resources:Speech Therapyassess swallowingPhysical Therapy—ambulation/strengtheningBowel/BladderAppropriate self-help resources

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