CEREBRAL VASCULARACCIDENT

Raja

Nursing Instructor

Acknowledgement: Badil31/03/2016

Objectives:

Define Cerebro vascular Accident (CVA)

Describe the causes of CVA

Understand the pathophysiology of CVA

List the sign and symptoms of CVA

Define Cerebro vascular Accident (CVA)

Describe the causes of CVA

Understand the pathophysiology of CVA

List the sign and symptoms of CVA

Cerebral regulation

The blood flow to the brain is maintained at

approximately 750 mL/minute or one sixth of the

resting cardiac output.

The blood flow to the brain is maintained at

approximately 750 mL/minute or one sixth of the

resting cardiac output.

Review of Cerebral Circulation

Blood is supplied to the brain by two major pairs ofarteries

Internal carotid arteriesVertebral arteries

Blood is supplied to the brain by two major pairs ofarteries

Internal carotid arteriesVertebral arteries

Carotid Arteries supply

Carotid arteries branch to supply most of the

Frontal, parietal, and temporal lobes

Basal ganglia

Diencephalon (Part of the brain that includes)

Thalamus

Hypothalamus

Carotid arteries branch to supply most of the

Frontal, parietal, and temporal lobes

Basal ganglia

Diencephalon (Part of the brain that includes)

Thalamus

Hypothalamus

Vertebral 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

Vertebral arteries join to form the basilar artery, which

supply the:

Middle and lower temporal lobes

Occipital lobes

Cerebellum

Brainstem

Part of the diencephalon

Carotid artery

Review of Cerebral Circulation

Cerebrovascular Accident

It is refereed as

stroke

Brain attack

Loss of brain function

More than 24 hours

Ischemia is inadequate blood flow

It is refereed as

stroke

Brain attack

Loss of brain function

More than 24 hours

Ischemia is inadequate blood flow

Conti….

Brain attack (Stroke) occurs when there is ischemia

to a part of the brain that results in death of brain

cells

Stroke is the syndrome of acute focal neurologic

deficit from a vascular disorder that injures brain

tissue

Brain attack (Stroke) occurs when there is ischemia

to a part of the brain that results in death of brain

cells

Stroke is the syndrome of acute focal neurologic

deficit from a vascular disorder that injures brain

tissue

Risk Factors

Non Modifiable

Age

Sex

Heredity

Non Modifiable

Age

Sex

Heredity

Modifiable Risk Factors

Obesity

HTN

Smoking

Heavy alcohol

consumption

Hypercoagulability

Hyperlipidemia

Diabetes mellitus

Atrial fibrillation

Oral contraceptives

Physical inactivity

Sickle cell disease

Cocaine

Obesity

HTN

Smoking

Heavy alcohol

consumption

Hypercoagulability

Hyperlipidemia

Diabetes mellitus

Atrial fibrillation

Oral contraceptives

Physical inactivity

Sickle cell disease

Cocaine

Types of CVA

Two main types of strokes:

Ischemic

Hemorrhagic

The less common hemorrhagic strokes are caused by

bleeding into brain tissue.

This type of stroke usually is from a blood vessel

rupture caused by hypertension, aneurysms, head

injury, or blood dyscrasias

Two main types of strokes:

Ischemic

Hemorrhagic

The less common hemorrhagic strokes are caused by

bleeding into brain tissue.

This type of stroke usually is from a blood vessel

rupture caused by hypertension, aneurysms, head

injury, or blood dyscrasias

Ischemic stroke

Ischemic strokes are caused by an interruption of

blood flow in a cerebral vessel

most common type of stroke

It account s for 70% to 80% of all strokes

It is Caused by cerebrovascular obstruction by

thrombosis or emboli

Ischemic strokes are caused by an interruption of

blood flow in a cerebral vessel

most common type of stroke

It account s for 70% to 80% of all strokes

It is Caused by cerebrovascular obstruction by

thrombosis or emboli

Types of Ischemic stroke

Ischemic Penumbra in Evolving Stroke

There usually is a central core of dead or

dying cells, surrounded by an ischemic band or

area of minimally perfused cells called the

penumbra

Brain cells of the penumbra receive marginal blood

flow, and their metabolic activities are impaired

Ischemic Penumbra in Evolving Stroke

There usually is a central core of dead or

dying cells, surrounded by an ischemic band or

area of minimally perfused cells called the

penumbra

Brain cells of the penumbra receive marginal blood

flow, and their metabolic activities are impaired

Ischemic Penumbra

Transient Ischemic Attacks

Transient ischemic attacks (TIAs) are characterized byfocal ischemic cerebral neurologic deficits that last forless than 24 hours (usually less than 1 to 2 hours).

TIA is equivalent to “brain angina” It is known as “ministroke” It reflects a temporary disturbance in focal cerebral blood

flow. Causes include Atherosclerotic disease of cerebral vessels Emboli in cerebral vessels

Transient ischemic attacks (TIAs) are characterized byfocal ischemic cerebral neurologic deficits that last forless than 24 hours (usually less than 1 to 2 hours).

TIA is equivalent to “brain angina” It is known as “ministroke” It reflects a temporary disturbance in focal cerebral blood

flow. Causes include Atherosclerotic disease of cerebral vessels Emboli in cerebral vessels

Large Vessel (Thrombotic) Stroke

Thrombi are the most common cause of ischemicstrokes, usually occurring in atherosclerotic bloodvessels.

In the cerebral circulation, atherosclerotic plaques arefound most commonly at arterial bifurcations.

Common sites of plaque formation include largervessels of the brain Internal carotid

Vertebral arteries

Junctions of the basilar and vertebral arteries.

Thrombi are the most common cause of ischemicstrokes, usually occurring in atherosclerotic bloodvessels.

In the cerebral circulation, atherosclerotic plaques arefound most commonly at arterial bifurcations.

Common sites of plaque formation include largervessels of the brain Internal carotid

Vertebral arteries

Junctions of the basilar and vertebral arteries.

Conti…

Cerebral infarction can result from an acute localthrombosis and occlusion at the site of

chronic atherosclerosis

Usually, thrombotic strokes are seen in older persons

It is frequently are accompanied by evidence ofatherosclerotic heart or peripheral arterial disease.

These infarcts often affect the cortex, causingAphasia

Visual field defects

Transient monocular blindness (amaurosis fugax)

Cerebral infarction can result from an acute localthrombosis and occlusion at the site of

chronic atherosclerosis

Usually, thrombotic strokes are seen in older persons

It is frequently are accompanied by evidence ofatherosclerotic heart or peripheral arterial disease.

These infarcts often affect the cortex, causingAphasia

Visual field defects

Transient monocular blindness (amaurosis fugax)

Small Vessel Stroke (Lacunar Infarct)

Lacunar infarcts are small (1.5 to 2 cm) to very small (3 to 4mm) infarcts

located in the deeper, noncortical parts of the brain or in thebrain stem

Affects Basal ganglia, or brain stem Six basic causes of lacunar infarcts have been proposed: Embolism Hypertension Small vessel occlusive disease Hematologic abnormalities Small intracerebral hemorrhages Vasospasm

Lacunar infarcts are small (1.5 to 2 cm) to very small (3 to 4mm) infarcts

located in the deeper, noncortical parts of the brain or in thebrain stem

Affects Basal ganglia, or brain stem Six basic causes of lacunar infarcts have been proposed: Embolism Hypertension Small vessel occlusive disease Hematologic abnormalities Small intracerebral hemorrhages Vasospasm

Cardiogenic Embolic Stroke

It is caused by a moving blood clot that travels from itsorigin to the brain.

It usually affects the larger proximal cerebral vesselsoften lodging at bifurcations.

The most frequent site of embolic strokes is the middlecerebral artery.

Although most cerebral emboli originate from a thrombus in the left heart, they also may

originate in an atherosclerotic plaque in the carotidarteries.

The embolus travels quickly to the brain and becomeslodged in a smaller artery through which it cannot pass.

It is caused by a moving blood clot that travels from itsorigin to the brain.

It usually affects the larger proximal cerebral vesselsoften lodging at bifurcations.

The most frequent site of embolic strokes is the middlecerebral artery.

Although most cerebral emboli originate from a thrombus in the left heart, they also may

originate in an atherosclerotic plaque in the carotidarteries.

The embolus travels quickly to the brain and becomeslodged in a smaller artery through which it cannot pass.

Hemorrhagic Stroke

The most frequently fatal stroke is a spontaneoushemorrhage into the brain substance.

With rupture of a blood vessel, hemorrhage into thebrain tissue occurs

It causes in edema, compression of the braincontents, or spasm of the adjacent blood vessels

The most common predisposing factors areadvancing age and hypertension.

The most frequently fatal stroke is a spontaneoushemorrhage into the brain substance.

With rupture of a blood vessel, hemorrhage into thebrain tissue occurs

It causes in edema, compression of the braincontents, or spasm of the adjacent blood vessels

The most common predisposing factors areadvancing age and hypertension.

Ischemic strokes

Ischemic strokes are subdivided into five different types

according to their cause:

large artery thrombosis (20%)

small penetrating artery thrombosis (25%)

Cardiogenic embolic stroke (20%)

Cryptogenic (30%)

Other (5%)

Ischemic strokes are subdivided into five different types

according to their cause:

large artery thrombosis (20%)

small penetrating artery thrombosis (25%)

Cardiogenic embolic stroke (20%)

Cryptogenic (30%)

Other (5%)

Diagnosis

Accurate diagnosis of acute stroke is based on

a complete history and thorough physical andneurologic examination.

A careful history, including documentation

of previous TIAs, the time of onset and pattern andrapidity of system progression, the specific focalsymptoms

Accurate diagnosis of acute stroke is based on

a complete history and thorough physical andneurologic examination.

A careful history, including documentation

of previous TIAs, the time of onset and pattern andrapidity of system progression, the specific focalsymptoms

Sites of ischemic attacks

Conti…

CT scan for hemorrhage

MRI (Magnetic resonance imaging)

MRA (Magnetic resonance angiography) forvesicular lesion

Positron-emission tomography (PET)

Single-photon emission computed tomography Positron-emission tomography and

Single-photon emission computed tomography

are nuclear studies used to assess the distribution ofblood flow and metabolic activity of the brain

CT scan for hemorrhage

MRI (Magnetic resonance imaging)

MRA (Magnetic resonance angiography) forvesicular lesion

Positron-emission tomography (PET)

Single-photon emission computed tomography Positron-emission tomography and

Single-photon emission computed tomography

are nuclear studies used to assess the distribution ofblood flow and metabolic activity of the brain

Additional studies

Complete blood count

Platelets count

Prothrombin time

Electrolytes, blood glucose

Renal and hepatic studies

Lipid profile

Complete blood count

Platelets count

Prothrombin time

Electrolytes, blood glucose

Renal and hepatic studies

Lipid profile

Treatment

Thrombolytic agents include streptokinase,

recombinant tissue-type plasminogen activator (tPA)

Platelet-inhibiting medications (aspirin)

Thrombolytic agents include streptokinase,

recombinant tissue-type plasminogen activator (tPA)

Platelet-inhibiting medications (aspirin)

References:

Porth, M. C. (2002). Pathophysiology: Concepts ofAltered Health Sciences. (6th ED). USA:

New York. Lippincott Williams &Wilkins