Cerebrovascular Accident/Stroke
=INTRODUCTION=
Cerebrovascular accidents (CVAs), or strokes, continue to be a national health problem despite recent advances in medical
technology
Stroke ranks as the third leading cause of death behind heart disease and cancer.
On average, a U.S. citizen suffers a stroke every 40 seconds; every 4 minutes someone dies of a stroke.
Each year, 795,000 people suffer a new or recurrent stroke. Approximately 610,000 strokes are first attacks and 185,000 are
recurrent
Of people who suffer a stroke, 28% are younger than 65 years. For people older than 55, the incidence of stroke more than doubles
with each successive decade
The incidence of stroke is about 1.25 times higher in men than in women
aftermath of a stroke is a substantial public health and economic problem
Among long-term clients who sustained a stroke, 50% have hemiparesis, 30% cannot walk, 26% are found to be dependent in activity
of daily living (ADL) scales, 19% are aphasic, 35% are clinically depressed, and 26% require home nursing care
=DEFINITION=
CVA / Stroke
- a complex dysfunction caused by a lesion in the brain
- WHO: “acute neurologic dysfunction of vascular origin with symptoms and signs corresponding to the involvement of focal areas of the brain”
- Stroke results in upper motor neuron dysfunction - hemiplegia, or paralysis of one side of the body, including the limbs and trunk and
sometimes the face and oral structures that are contralateral to the hemisphere of the brain with the lesion.
- left CVA = right hemiplegia
- right CVA = left hemiplegia
- accompanying dysfunctions:
- sensory disturbances
- cognitive and perceptual dysfunction
- visual disturbances
- personality and intellectual changes
- complex range of speech and associated language disorders
- neurologic deficits must persist longer than 24 hours to be labeled a CVA
=ANATOMY=
BRAIN
> The two cerebral hemispheres are divided into four lobes: frontal, parietal, occipital, and temporal.
> The frontal lobe is separated from the parietal lobe by the central sulcus.
- All behavioral motor output originating in the frontal lobe, including mobility, object manipulation, directional eye
movement, and verbal expression, are assisted by the basal ganglia and cerebellum.
> In contrast, processing of all visual, auditory, and somatosensory input is integrated in the thalamus, parietal, occipital, and
temporal lobes.
> There are also significant interconnections between primary motor cortex and somatosensory cortex, premotor and ventral motor
areas, as well as connections from the thalamus to the motor cortex and from the motor cortex to the basal ganglia,
superior and inferior colliculi, and cerebellum.
- Meninges - surround and protect the brain
Dura mater – outer
Extensions:
falx cerebri - separates the two hemispheres (sides) of the cerebrum.
falx cerebelli - separates the two hemispheres of the cerebellum.
tentorium cerebelli - separates the cerebrum from the cerebellum
Arachnoid mater - middle
Pia mater – inner
- Divisions of Brain
Hindbrain
Medulla Oblongata
- conical in shape
- connects the pons superiorly to the spinal cord inferiorly
- contain nuclei
- serves as a conduit for ascending and descending nerve fibers
Pons
- situated on:
= anterior surface of the cerebellum
= inferior to the midbrain
= superior to the medulla oblongata
- large number of transverse fibers on its anterior aspect connecting the two cerebellar hemispheres.
, - It also contains many nuclei and ascending and descending nerve fibers
Cerebellum
- situated on:
= posterior cranial fossa of the skull
= posterior to the pons and the medulla oblongata
- consists of two laterally placed hemispheres connected by a median portion, the vermis
- connected to:
= midbrain by superior cerebellar peduncles
= pons by the middle cerebellar peduncles
= medulla by the inferior cerebellar peduncles
Midbrain - narrow part of the brain that connects the forebrain to the hindbrain
Forebrain
Diencephalon
- almost completely hidden from the surface of the brain
- consists of:
> dorsal thalamus
> ventral hypothalamus
Cerebrum
- largest part of the brain
- consists of two cerebral hemispheres
- corpus callosum – a mass of white matter that connects the two cerebral hemispheres
-Brainstem
> collective term for the medulla oblongata, pons, and midbrain
> part of the brain that remains after the cerebral hemispheres and cerebellum are removed
CIRCLE OF WILLIS
- is a confluence (actually a hexagon) of vessels that gives rise to all of the major cerebral arteries.
ophthalmic artery- It supplies the eye and other orbital structures, and its terminal branches supply the frontal area of the scalp, the ethmoid
and frontal sinuses, and the dorsum of the nose.
anterior cerebral artery- The anterior cerebral artery thus supplies the “leg area” of the precentral gyrus. A group of central branches pierces
the anterior perforated substance and helps to supply parts of the lentiform and caudate nuclei and the internal capsule.
MCA- Cortical branches supply the entire lateral surface of the hemisphere, except for the narrow strip supplied by the anterior cerebral artery,
the occipital pole, and the inferolateral surface of the hemisphere, which are supplied by the posterior cerebral artery This artery thus supplies
all the motor area except the “leg area.” Central branches enter the anterior perforated substance and supply the lentiform and caudate nuclei
and the internal capsule
posterior inferior cerebellar artery- It supplies the inferior surface of the vermis, the central nuclei of the cerebellum, and the undersurface of
the cerebellar hemisphere; it also supplies the medulla oblongata and the choroid plexus of the fourth ventricle.
anterior inferior cerebellar artery passes posteriorly and laterally and supplies the anterior and inferior parts of the cerebellum
superior cerebellar artery- It also supplies the pons, the pineal gland.
posterior cerebral artery- Cortical branches supply the inferolateral and medial surfaces of the temporal lobe and the lateral and medial
surfaces of the occipital lobe
=CAUSES=
- Ischemic strokes account for the majority of strokes
- Hemorrhagic strokes account for less
ISCHEMIA
- insufficient blood flow to the brain to meet metabolic demand
- Ischemic strokes - may be the result of embolism to the brain from cardiac or arterial sources
*Cardiac Sources:
- atrial fibrillation (pooling of blood in the dysfunctional atrium leads to the production of emboli)
- sinoatrial disorders
- acute myocardial infarction
- endocarditis
- cardiac tumors
- valvular (both native and artificial) disorders
=INTRODUCTION=
Cerebrovascular accidents (CVAs), or strokes, continue to be a national health problem despite recent advances in medical
technology
Stroke ranks as the third leading cause of death behind heart disease and cancer.
On average, a U.S. citizen suffers a stroke every 40 seconds; every 4 minutes someone dies of a stroke.
Each year, 795,000 people suffer a new or recurrent stroke. Approximately 610,000 strokes are first attacks and 185,000 are
recurrent
Of people who suffer a stroke, 28% are younger than 65 years. For people older than 55, the incidence of stroke more than doubles
with each successive decade
The incidence of stroke is about 1.25 times higher in men than in women
aftermath of a stroke is a substantial public health and economic problem
Among long-term clients who sustained a stroke, 50% have hemiparesis, 30% cannot walk, 26% are found to be dependent in activity
of daily living (ADL) scales, 19% are aphasic, 35% are clinically depressed, and 26% require home nursing care
=DEFINITION=
CVA / Stroke
- a complex dysfunction caused by a lesion in the brain
- WHO: “acute neurologic dysfunction of vascular origin with symptoms and signs corresponding to the involvement of focal areas of the brain”
- Stroke results in upper motor neuron dysfunction - hemiplegia, or paralysis of one side of the body, including the limbs and trunk and
sometimes the face and oral structures that are contralateral to the hemisphere of the brain with the lesion.
- left CVA = right hemiplegia
- right CVA = left hemiplegia
- accompanying dysfunctions:
- sensory disturbances
- cognitive and perceptual dysfunction
- visual disturbances
- personality and intellectual changes
- complex range of speech and associated language disorders
- neurologic deficits must persist longer than 24 hours to be labeled a CVA
=ANATOMY=
BRAIN
> The two cerebral hemispheres are divided into four lobes: frontal, parietal, occipital, and temporal.
> The frontal lobe is separated from the parietal lobe by the central sulcus.
- All behavioral motor output originating in the frontal lobe, including mobility, object manipulation, directional eye
movement, and verbal expression, are assisted by the basal ganglia and cerebellum.
> In contrast, processing of all visual, auditory, and somatosensory input is integrated in the thalamus, parietal, occipital, and
temporal lobes.
> There are also significant interconnections between primary motor cortex and somatosensory cortex, premotor and ventral motor
areas, as well as connections from the thalamus to the motor cortex and from the motor cortex to the basal ganglia,
superior and inferior colliculi, and cerebellum.
- Meninges - surround and protect the brain
Dura mater – outer
Extensions:
falx cerebri - separates the two hemispheres (sides) of the cerebrum.
falx cerebelli - separates the two hemispheres of the cerebellum.
tentorium cerebelli - separates the cerebrum from the cerebellum
Arachnoid mater - middle
Pia mater – inner
- Divisions of Brain
Hindbrain
Medulla Oblongata
- conical in shape
- connects the pons superiorly to the spinal cord inferiorly
- contain nuclei
- serves as a conduit for ascending and descending nerve fibers
Pons
- situated on:
= anterior surface of the cerebellum
= inferior to the midbrain
= superior to the medulla oblongata
- large number of transverse fibers on its anterior aspect connecting the two cerebellar hemispheres.
, - It also contains many nuclei and ascending and descending nerve fibers
Cerebellum
- situated on:
= posterior cranial fossa of the skull
= posterior to the pons and the medulla oblongata
- consists of two laterally placed hemispheres connected by a median portion, the vermis
- connected to:
= midbrain by superior cerebellar peduncles
= pons by the middle cerebellar peduncles
= medulla by the inferior cerebellar peduncles
Midbrain - narrow part of the brain that connects the forebrain to the hindbrain
Forebrain
Diencephalon
- almost completely hidden from the surface of the brain
- consists of:
> dorsal thalamus
> ventral hypothalamus
Cerebrum
- largest part of the brain
- consists of two cerebral hemispheres
- corpus callosum – a mass of white matter that connects the two cerebral hemispheres
-Brainstem
> collective term for the medulla oblongata, pons, and midbrain
> part of the brain that remains after the cerebral hemispheres and cerebellum are removed
CIRCLE OF WILLIS
- is a confluence (actually a hexagon) of vessels that gives rise to all of the major cerebral arteries.
ophthalmic artery- It supplies the eye and other orbital structures, and its terminal branches supply the frontal area of the scalp, the ethmoid
and frontal sinuses, and the dorsum of the nose.
anterior cerebral artery- The anterior cerebral artery thus supplies the “leg area” of the precentral gyrus. A group of central branches pierces
the anterior perforated substance and helps to supply parts of the lentiform and caudate nuclei and the internal capsule.
MCA- Cortical branches supply the entire lateral surface of the hemisphere, except for the narrow strip supplied by the anterior cerebral artery,
the occipital pole, and the inferolateral surface of the hemisphere, which are supplied by the posterior cerebral artery This artery thus supplies
all the motor area except the “leg area.” Central branches enter the anterior perforated substance and supply the lentiform and caudate nuclei
and the internal capsule
posterior inferior cerebellar artery- It supplies the inferior surface of the vermis, the central nuclei of the cerebellum, and the undersurface of
the cerebellar hemisphere; it also supplies the medulla oblongata and the choroid plexus of the fourth ventricle.
anterior inferior cerebellar artery passes posteriorly and laterally and supplies the anterior and inferior parts of the cerebellum
superior cerebellar artery- It also supplies the pons, the pineal gland.
posterior cerebral artery- Cortical branches supply the inferolateral and medial surfaces of the temporal lobe and the lateral and medial
surfaces of the occipital lobe
=CAUSES=
- Ischemic strokes account for the majority of strokes
- Hemorrhagic strokes account for less
ISCHEMIA
- insufficient blood flow to the brain to meet metabolic demand
- Ischemic strokes - may be the result of embolism to the brain from cardiac or arterial sources
*Cardiac Sources:
- atrial fibrillation (pooling of blood in the dysfunctional atrium leads to the production of emboli)
- sinoatrial disorders
- acute myocardial infarction
- endocarditis
- cardiac tumors
- valvular (both native and artificial) disorders
