Module 12 Flashcards
What is a Stroke
clinical syndrome consisting of a constellation of neurologic findings, sudden or rapid in onset, which persist for more than 24 hours and whose vascular origins are limited to thrombotic or embolic occlusion of a cerebral artery resulting in infarction or a spontaneous rupture of a vessel resulting in intracerebral or subarachnoid hemorrhage”
Syndrome
compilation of signs and symptoms going together
Each person has a different looking __
stroke
Key Aspects of a Stroke
- Pathologic process affecting blood vessels that results in occlusion or rupture of blood vessels
- Resultant damage to brain tissue in area served by occluded or ruptured vessel
- Neurologic sequelae as a result of interrupted blood flow
A stoke is also known as a …
Brain Attack (a vascular disorder that injures brain tissue)
___ is one of the leading causes of morbidity and mortality in the US
Stroke
The longer the wait and delay in stroke treatment…
the more likely for irreversible damage
What are the 2 different types of strokes?
- Ischemic Stroke
- Hemorrhagic Stroke
___ Strokes are more common and make up 80% of strokes
Ischemic
Ischemic strokes are caused by ..
an interruption of blood flow in a cerebral vessels of thrombotic (50%) or embolic (30%) origin
Hemorrhagic strokes are caused by ..
bleeding into brain tissue d/t hypertension (10%), aneurysms (6%), AV Malformations, head injury, or blood dycrasias
___ strokes are less common BUT have a higher fatality rate
Hemorrhagic
Most ischemic strokes have embolisms come from somewhere between…
the left heart and brain (heart –> neck –> mid cerebral artery) since the path is of least resistance and is a straight line
The goal for an ischemic stroke is to …
return perfusion as fast as possible
What are examples of ischemic stroke treatments?
Anticoagulants
Removal of atherosclerosis/Arteriosclerosis
Coiling
treatment for ischemic strokes involving retrieving the clot and restoring perfusion
Blood Dyscrasias
abnormal amounts of other elements in the blood
Which stroke type is harder to treat?
Hemorrhagic
Strokes are the ____ leading global cause of death behind ___ ___
2nd; Heart Disease
Potential Stroke Sequelae?
- 22% of men and 25% of women die within
- stroke within 6 years of an MI
- half of men and women <65 die within 8 years
- 14% of TIA or stroke will have recurrence in first year
- 50-70% regain functional independence BUT 15-30% are permanently disabled
Modifiable Risk Factors for Strokes?
HTN
Cigarettes
High chol
Alcohol Use
Obesity
heart disease
diabetes mellitus
cocaine and other drugs
sedentary lifestyle
Non Modifiable Risk Factors for Strokes?
Age
Gender
Race
family history
Sickle cell disease
Polycythemia
What is the most important and common precursor to stroke?
Hypertension
Most common warning signs for stroke?
Sudden numbness, weakness, or facial/arm/leg paralysis - usually unilateral
Loss of speech, trouble walking, or trouble understanding speech
Sudden blurred or decreased vision, usually in one eye
Dizziness, loss of balance, or loss of coordination
sudden, severe headache with no apparent cause
difficulty swallowing
Usually people have what in regard to common stroke warning signs?
some but not all of them at once
Embolus
moving clot
thrombus
clot`
F A S T
Facial drooping Arm weakness Speech difficulty Time
Types and Frequency of Ischemic Strokes
16% - Atherosclerotic or Non Atherosclerotic Large Cerebral Artery Disease
27% - Penetrating artery disease
19% - Cardioembolic strokes
40% - strokes of undetermined origins
8% - misc (sickle cell or migraine)
Atherosclerotic Strokes cause what kind of strokes/damage?
Watershed Strokes (Border damage)
Penetrating Artery disease Strokes cause what kind of strokes/damage?
laminar strokes/lacunar necrosis
Cardioembolic strokes cause are due to waht?
embolus traveling from the carotid to (usually) the mid cerebral arteries
Transient Ischemic Attack (TIA)
Ischemic stroke characterized by focal ischemic cerebral neurologic deficits that last <24 hours (temporary and has little to no damage after)
person may not even realize it happened
Causes of TIA
Atherosclerosis Disease
Emboli
TIA may provide a warning for …
impending stroke
Early diagnosis of TIA may permit what …
early intervention and prevent extensive damage
TIA imaging shows…
NO necrosis of tissue in the brain (no area of central infarction)
S/S of TIA
Depend on cerebral vessel involved!!!:
Numbness and mild weakness on one side that persists briefly then resolves
Forearm, hand, and angle of mouth commonly affected
Transient visual disturbances (graying out, blurring, fogging of vision)
Rarely: Vertigo, dizziness, confusion, amnesia, seizures
Ways to Dx a TIA
CT Scan
Cerebrovascular Arterial Imaging (CAI)
cardiac Imaging
CT Scan
always used for strokes of suspected strokes
tells if the stroke is due to bleeding or a clot
CAI looks at
arteries (related to stroke)
Cardiac Imaging reveals…
reasoning for embolus formation
How is TIA treated?
Depending on the type and location via pharmacologic, medications, avoidance, and surgery
Pharmacologic treatments for TIA
Aspirin, Antiplatelet drugs, Anticoagulants
Can we use the same pharmacologic treatments (ex: anticoagulants) on a hemorrhagic stroke?
NO, it will thin the blood and make bleeding worse
Why is it important to avoid dehydration and hypotension when treating TIA?
the two can further compromise blood flow to the brain thus increasing ICP
(therefore be careful when lowering Bp with Meds for HTN)
Its important to use medications that lower BP for HTN judiciously when dealing with TIA because …
the hypotension could cause increased ICP and complicate blood flow to the brain
How does surgery treat TIA?
via removal of atherosclerotic plaques
Carotid Endarterectomy
surgery for removal of atherosclerotic plaque
Indicated by one or more TIA or mild stroke in the last 6 months and carotid stenosis >70%
Extracranial-Intracranial Bypass
surgery for redirecting blood flow from an artery in the scalp through the cranium to cerebral arteries (treatment for TIA)
Thrombotic Stroke
Ischemic Stroke type
It is the gradual blockage of a vessel usually occurring in atherosclerotic blood vessels - primarily at bifurcations
often accompanied by evidence of arteriosclerotic heart disease
The most common cause of ischemic stroke is …
Thrombotic Stroke
Thrombotic strokes are ___ ___ with activity and ___ occur at rest
not associated with activity and CAN occur at rest
Thrombotic strokes most often occur at …
bifurcations (areas of high stress and turbulent blood flow)
Thrombotic strokes tend to occur in ___ persons
older
How do thrombotic strokes relate to consciousness>?
consciousness may or may not be lost
Lacunar Infarcts
Type of ischemic stroke
small to very small (1.5-2 cm or 3-4 mm) infarcts in deeper noncortical parts of the brain or the brain stem
Found in area of deep penetrating arteries supplying the internal capsule, basal ganglia or brain stem
occlusion of smaller branches occur here
Most common arteries for lacunar infarcts?
middle or posterior cerebral arteries
Lacunar Infarcts are also known as …
Pinpoint death of tissue
Lacuna
small cavities after healing from lacunar infarcts revealing pinpoint areas of tissue death
function is lost here
What are the deficits like in lacunar infarcts?
Usually not profound, more specific/defined (ex: cannot multiply but can still add, subtract, divide, etc)
Causes of Lacunar Infarcts
Embolism
HTN
Small vessel occlusive disease
hematologic abnormalities
small intracerebral hemorrhages
vasospasms
Cardiogenic Embolic Stroke
Cardiogenic = coming from heart ; embolism stroke (ischemic in nature)
Sudden onset, immediate maximum deficit strokes usually coming from the left heart or the carotid
An embolism travels into a vessel and causes lack of blood supply to an area leading to brain tissue death
Cardiogenic Embolic Strokes usually affect …
smaller cerebral vessels, often at bifurcations
Most frequent site for cardiogenic embolic strokes?
middle cerebral artery distribution (offers path of least resistance from left heart or carotid)
Predisposing conditions for Cardiogenic Embolic Stroke
Rheumatic heart disease
Atrial fibrillation
recent MI
ventricular aneurysm
bacterial endocarditis
Cardiogenic embolic stroke incidence decreases with …
increased treatment of heart disease
Penumbra
In ischemic strokes, a central core of dead/dying cells exist past clots
The core is surrounded by ischemic area of minimally surviving cells known as the penumbra (halo)
cells here get marginal blood flow, altered metabolism, and undergo electrical failure, BUT structural integrity is maintained
ITS STILL ALIVE (For now)
Survival of penumbra depends on…
return of adequate circulation
volume of toxic products released
degree of cerebral edema (since viscous blood as a result makes it hard to get blood flow)
alterations in local blood flow
With ischemic penumbra, we want to …
restore blood flow to the penumbra area ASAP
Hemorrhagic Stroke
Stroke due to the rupture of a blood vessel and bleeding into the brain
Most common predisposing factor for hemorrhagic strokes is …
hypertension
Attempts by the brain to compensate for hemorrhagic stroke?
Edema
compression of brain contents
spasm of adjacent blood vessels
(does not help)
Causes for Hemorrhagic Stroke?
Aneurysm
Spontaneous intracerebral hemorrhage
AV malformations
Others: Trauma, erosion of the vessels by tumors, coagulopathies, vasculitis, drugs
HTN
We do not use anticoagulants like aspirin on hemorrhagic stroke patients since…
it can extend bleeding
Hemorrhagic strokes occur …
suddenly; usually when a person is active (unlike thrombotic which is at rest)
___ is common at onset of a hemorrhagic stroke, sometimes with ___
vomiting; headache
Focal symptoms of hemorrhagic stroke depend on…
which vessel is involved
Hemorrhage into the internal capsule (deep brain) leads to …
contralateral hemiplegia with initial flaccidity progressing to spasticity (of reflex arcs)
Clinical course of hemorrhagic stroke often progresses rapidly to …
coma and frequently to death
There is ___ treatment for hemorrhagic stroke
little treatment ; most treatment is supportive in nature
Acute Manifestations of strokes are determined by ..
Affected Cerebral Artery
Area of brain Supplies
Adequacy of collateral circulation
Acute Manifestations of Stroke may include ..
Loss of Consciousness
cognitive and motor disorders
specific motor or sensory impairment
aphasia
hemi-neglect syndrome
Aphasia
partial or total loss of written and verbal communication
Hemi-neglect syndrome
do not recognize half of the body
Anterior Cerebral Artery can have effects on what parts of the brain if occluded d/t stroke?
Infarction of medial aspect of 1 frontal lobe (if distal to communicating artery)
Bilateral frontal infarction (if flow in other anterior cerebral artery is inadequate)
S/S of Anterior Cerebral Artery Stroke
Paralysis of contralateral foot or leg
Impaired gait
Paresis of contralateral arm
Contralateral sensory loss over toes, foot, and leg
Problems making decisions or performing acts voluntarily
Lack of spontaneity, easily distracted
Slowness of thought
Aphasia depends on the hemisphere involved
Urinary incontinence
Cognitive & affective disorders (emotion and personality changes)
Middle Cerebral Artery can have effects on what parts of the brain if occluded d/t stroke?
Massive infarction of most of the lateral hemisphere and deeper structures of the frontal, parietal, and temporal lobes; internal capsule; basal ganglia
The middle cerebral artery feeds…
a lot of the brain
____ is the most common area for infarction
Basal Ganglia
Anterior and Middle Cerebral Arteries feed ___ and ____ ___ which is important to think about in regard to stroke manifestations
motor and sensory cortexes
S/S of Middle Cerebral Artery Stroke
Contralateral hemiplegia (face & arm)
Contralateral sensory impairment
Aphasia
Homonymous hemianopsia
Altered consciousness (confusion to coma)
Inability to turn eyes toward paralyzed side
Denial of paralyzed side or limb (hemi-attention)
Possible acalculia (inability to perform calculations)
Alexia (word blindness)
Finger agnosia (inability to identify fingers)
Left-right confusion
Vasomotor paresis & instability
S/S of the middle cerebral artery strokes often cause issues in the ___ side
contralateral
Posterior Cerebral Artery can have effects on what parts of the brain if occluded d/t stroke?
Occipital Lobe (vision)
Anterior and Medial portion of temporal lobe
Thalamus and Cerebral Peduncle
S/S of Posterior Cerebral Artery stroke affecting the Occipital lobe and anterior & medial portion of the temporal lobe
Homonymous hemianopsia
Color blindness
Loss of central vision
Visual hallucinations
Memory deficits
Perseveration (repeated performance of same verbal or motor response)
S/S of Posterior Cerebral Artery stroke affecting the Thalamus
Loss of all sensory modalities
Spontaneous pain
Intentional tremor
Mild hemiparesis
Aphasia
(YOU COULD LOSE ALL SENSORY MODALITIES (except smell))
S/S of Posterior Cerebral Artery stroke affecting the Cerebral peduncle
oculomotor nerve palsy (CNIII) with contralateral hemiplegia
(cannot maintain normal alignment of eyes when looking straight ahead, can give drooping eyelid or double vision)
Basilar and Vertebral Arteries can have effects on what parts of the brain if occluded d/t stroke?
Cerebellum and Brain Stem (vision and balance greatly effected)
S/S of Basilar and Vertebral Artery Stroke
Visual disturbances
diplopia
dystaxia
vertigo
dysphagia
dysphonia
Diplopia
double vision
Dystaxia
difficulty with muscle coordination
Vertigo
disturbances of equilibrium; sensation of everything moving around in space
Dysphagia
Difficulty swallowing
Dysphonia
difficulty speaking (hoarseness, excessively breathy sounds since they cannot use vocal organs correctly)
Most common signs fo stroke
sudden severe headache
weakness of one side
impaired balance
loss of speech
confusion
FAST
Most common predisposing factor for stroke is …
untreated HTN
Ways to d/x stroke?
Complete History and physical with thorough neurologic exam
CT (computed tomography)
Arteriography
MRA
PET
SPECT
US
Arteriography
looks at blood flow to the brain
MRA
magnetic resonance arteriography
looks at blood flow and condition of the vessels
PET
positron emission tomography
look at glucose uptake to the brain (glc metabolism)
SPECT
single photon emission computed tomography
US
Doppler Ultrasound
what kind of flow is in the carotids
Emphasis of stroke treatment is on…
salvaging brain tissue and minimizing long term disability
Treatment for ischemic stroke involves a “window of opportunity” meaning what?
use of thrombolytic agents (clot breaking drugs) in early treatment should be used (streptokinase, urokinase, TPA)
Contraindications for Thrombolytic agents in the treatment of ischemic stroke?
oral anticoagulant use
history of GI bleeding
Recent MI
stroke or head injury in the past 3 months
surgery in the last 14 days
BP greater than or equal to 200/120 mmHg
What is treatment for hemorrhagic stroke like?
Less dramatic
More supportive, educate people on how stroke is like a heart attack and to seek immediate medical treatment, do NOT wait for Sxs to subside
focus on early rehabilitation
Anticoagulants do what in comparison to Thrombolic treatment?
Anticoagulants prevent clots while thrombolic lyses or breaks a clot
Important Potential Long Term Disabilities due to Stroke
Motor Deficits
Language and Speech Issues
Aphasia
Other: Dysarthria, Ataxia, Agnosia, Alexia, Anomia, conduction Aphasia, receptive/Fluent Aphasia
Denial or Hemi-Attention
If a stroke affects the corticospinal tract, what can occur?
profound weakness can occur on the contralateral (opposite) side
Areas affected by stroke leading to motor deficits?
Motor cortex
posterior limb of internal capsule
medullary pyramids
S/S of Motor Deficits due to Stroke
decrease/absence of normal muscle tone
immediate loss of fine manipulative skills
affected limbs tend to move as a hole –> foot drop, outward rotation of leg
dependent edema in affected extremity –> PROM
Why is it important to do PROM for people with stroke related motor deficits?
You need to help them do the ROM they cannot so the joint does not freeze
When muscle tone returns after a stroke, what happens
flaccidity is replaced by Spasticity (no control over the movement occurring 6-8 weeks) –> altered limb posturing ( shoulder adduction, forearm pronation, finger flexion, knee/hip extension) –> PROM
What is language?
Involves higher order integrative functions of the forebrain (speech, writing, math)
Used to communicate thought and feelings through use of symbolic formulations (words or numbers); information i9s transmitted vocally (spoken) or visually (written)
What is speech?
Involves mechanical act of articulating language = “motor act” of verbal expression
Depends on functional integrity of peripheral musculature and its control
Broca’s Area
Production of speech and flow from mouth (SPEECH)
Wernicke’s Area
interpretation and understanding of speech (LANGUAGE)
Dysarthria
imperfect articulation of speech sounds or changes in voice pitch or quality
caused by disturbed motor control
dysfunction of moving parts of speech; neurologic injury
Ataxia
defective muscular coordination
*difficulty walking
Agnosia
inability to recognize an object - may be tactile, visual, or auditory
involves structural damage to association centers of parietal, temporal, and occipital lobes
structural damage
Alexia
word blindness
Anomia
Difficulty recognizing or naming objects or colors
Conduction Aphasia
Inappropriate word use despite good comprehension
Results from destruction of fibers connecting Wernicke’s and Broca’s Areas
Neologism
invented words
occurs with receptive/fluent aphasia
3 Major Language and Speech Problems due to Stroke
Aphasia
Dysarthria
Apraxia
Disturbances of the central processing mechanisms of language is ___
Aphasia
Dysfunction of the larynx, pharynx, palate, tongue, lips or mouth is ___
Dysarthria
Inability to sequence voluntary movements needed for speech despite absence of motor deficits is ___
Apraxia
Aphasia encompassess.
varying degrees of inability to comprehend, integrate, and express language
Most common cause of Aphasia during stroke?
Occlusion of middle cerebral artery of the dominant hemisphere
The left hemisphere is dominant in ___% of right handed persons
90%
The right hemisphere is dominant in __% of left handed persons
70%
Receptive/Fluent Aphasia
Represents a sensory agnosia or inability to comprehend spoken words - may be visual or auditory
Affected area: Posterior temp[oral or lower parietal lobe - Wernicke Lesion
Motor intact, cannot receive and process info, so it comes out as nonsense
Also known as “Wernicke’s Aphasia”
Expressive or Nonfluent Aphasia
“Broca’s Aphasia”
characterized by inability to translate thoughts or ideas into meaningful speech or writing
Motor not intact
Affected area: Broca’s area (precentral gyrus) of the dominant frontal lobe
Where is Broca’s Area
Temporal region, left sideq
Where is Wernicke’s Area
occipital area, both right and left side
Damage of the bundle of fibers connecting Broca and Wernicke areas leads to…
conduction aphasia where language is understood but speech does not make sense as they cannot produce words
Denial or Hemi-attention
inability to analyze and interpret sensory info and internal production of abnormal signals –> denial of illness and denial of 1/2 body and surrounding environment
It is impaired spatial orientation with difficulty localizing stimuli, their own limbs, and objects in space
ex: they only eat half a tray of food and do not process the other half is there
Denial or Hemi-attention is most common in strokes that …
affect the non dominant side of the brain (right hemisphere) which is usually involved in spatial orientation, body image, and inductive reasoning
hemi-attention is a ___ AND ___ problem
vision and processing problem
Effects of Stroke on the Right Side
Motor - effects contralateral side (left):
Weakness (hemiparesis), paralysis (hemiplegia), or lack of coordination of face, arm, leg on left side
lack of feeling and position on the left side of the body
decreased ability to judge distances, size, positions, rate of movement, and form
inability to think clearly
loss of awareness of forgetting objects on the left side (left sided neglect). the neglect is usually more severe with strokes on the right side of the brain
quick and impulsive behavior
difficulty drawing, dressing, or following a map
Effects of Stroke on the Left Side
Motor - effects contralateral side (right):
Weakness (hemiparesis), paralysis (hemiplegia), or lack of coordination of the face, arm , or leg on the right side of the body
lack of feeling and position on the right side of the body
difficulty speaking (slurred or distorted speech), listening, writing, reading, calculating with numbers, or understanding what others say (aphasia)
Behavioral changes (slow, cautious, and somewhat disorganized)
Loss of awareness or forgetting objects on the right side
Symptoms of stroke on left and right side depend on…
which side of the brain is “dominant”. Some left handed people have speech and language difficulties with right sided strokes
Strokes make you lose…
A LOT of QOL - so be educational, patient, and kind
Teach the patient to pay attention to the side being neglected and the risk of running into things and falling that they may not see
Homonymous Hemianopia
Nasal and Temporal Visual Field Issues due to lesion in various areas
visual field defect depends on the location
Lesions can occur before chiasm, at chiasm, after chiasm
If there is a lesion of the optic nerve prior to the chiasm, what occurs?
You lose both nasal and temporal pathway/sight for that eye
*so if its a lesion on the right side, you go blind in the right eye
If there is a lesion of the optic nerve at the optic chiasm, what occurs?
2 things can occur: half the fields disappear, or you go blind everywhere
So you can either lose L and R nasal fields, lose L and R temporal fields, or go completely blind
If there is a lesion of the optic nerve after the chiasm, what occurs?
Homonymous Hemianopia
Homonymous means fibers are interrupted and the vision originating in the same side of both eyes is lost (ex: lose left nasal field and right temporal field which is right side of both eyes)
Hemianopia means tehre is a loss of vision from half of each field
Hemi-attention occurs from this
Stroke on the left visual field (post-chiasm) leads to what? what about the right visual field?
Left - loss of right visual field (right side vision on both eyes)
right - loss of left visual field (left side vison on both eyes)
What would cause and be seen by someone with left homonymous hemianopsia?
A stroke occurred post-chiasm on right side
They would only see the right side of both eyes (so their left visual field in both is blind)
Homonymous Hemianopsia can lead to what other condition?
Hemi-attention/denial
When interacting with a Homonymous Hemianopsia patient, it is important to do what?
Approach them on the side they can see you from to help, do not startle them, and help them relearn processes
you have to be patient and teach as its both a visual and processing disorder when hemi-attention occurs
