Stroke Flashcards
Stroke is …
Sudden loss of neurological function caused by an
interruption of blood flow to the brain.
Another name for stroke is …
cerebrovascular accident (CVA)
Ischemic stroke
- Most common type (80% of cases).
- Thrombosis, embolism, or hypoperfusion.
- Lack of oxygen/nutrients –> tissue
Hemorrhagic stroke
- When blood vessels rupture.
- Leakage of blood in or around the brain.
- Lead to increased intracranial pressures.
For a stroke to be classified as a stroke how long do the Neurological deficits have to last at least?
24 hours.
Hemiplegia is …
Paralysis
Hemiparesis is …
weakness
Hemorrhagic stroke is linked to …
chronic hypertension.
Stroke and age …
Increases dramatically with age, doubling
in the decade after the age of 65.
Stroke Risk factors
- Hypertension
- DM
- Heart Rhythm disorders
- High Blood Cholesterol
- Tobacco use
- Heart disease
Modifiable risk factors:
cigarette smoking, physical
inactivity, obesity, and diet.
A powerful determinant of risk for both ischemic &
hemorrhagic.
Blood pressure
A powerful risk factor for ischemic stroke (three
to fivefold).
Atrial Fibrillation
End Stage renal disease
Increases the risk of stroke.
Prevention F.A.S.T
F- face drooping
A- arm weakness
S- slurred speech
T- time to call the police
Pathophysiology
• Sudden oxygen glucose deprivation. • Neurons die in core tissue, survive in the surrounding penumbra. • No timely reperfusion, cells in the penumbra die, neuronal activity ceases, and the infarct expands.
Pathophysiology (Vascular Syndromes)
The severity of stroke depends on: • Location of the ischemic process • Size of the ischemic area • Nature & functions of involved structures • Availability of collateral blood flow
Pathophysiology (Vascular Syndromes)
The severity of stroke depends on: • Location of the ischemic process • Size of the ischemic area • Nature & functions of involved structures • Availability of collateral blood flow
Vascular Syndromes (ACA Syndrome)
- Contralateral hemiparesis (mainly the LE)
- Contralateral hemisensory loss (mainly the LE)
- Urinary incontinence
- Problems imitating & bimanual tasks, apraxia
- Slowness, lack of spontaneity, motor inaction
- Contralateral grasp reflex
Vascular Syndromes (MCA Syndrome)
• Contralateral hemiparesis (mainly the UE & face)
• Contralateral hemisensory loss (mainly the UE & face)
• Motor speech impairment:
Broca’s aphasia.
• Receptive speech impairment: Wernicke’s aphasia.
•Global aphasia.
• Unilateral neglect, depth perception, spatial relations, agnosia.
• Contralateral homonymous hemianopsia.
• Ataxia of contralateral limb(s).
Agnosia
Not able to interpret sensations and recognize objects
Ideational Apraxia
Loss of ability to carry out learned tasks in correct order
Ideomotor Apraxia
Loss of ability to perform learned tasks when provided with necessary objects
Vascular Syndromes (ICA Syndrome)
• Supplies both the MCA & the ACA.
• Occlusion produces massive infarction in
the region of the brain supplied by the
MCA.
• If no collateral to ACA from the circle of
Willis –> extensive ACA & MCA
• Significant edema is common w/ possible
uncal herniation, coma, and death.
Uncal Herniation
Image
Vascular Syndromes (PCA Syndrome) Peripheral Territory
- Contralateral homonymous hemianopsia.
- Visual agnosia.
- Prosopagnosia.
- Dyslexia w/o agraphia, anomia.
- Memory defect.
- Topographic disorientation.
Vascular Syndromes (PCA Syndrome) Central Territory
- Thalamic pain.
- Sensory impairments (all modalities).
- Involuntary movements.
- Contralateral hemiplegia.
- Weber’s syndrome.
- Paresis of vertical eye movements.
Visual agnosia
cannot perceive what you see
Prosopagnosia
blind in being able to see faces
Anomia
can not name colors
Weber’s syndrome
paralysis to oculomotor nerve damage ipsilateral and contralateral hemiparesis
Vascular Syndromes (Lacunar Strokes)
• Small vessel disease deep in the cerebral white
matter.
• Associated w/ hypertensive hemorrhage &
diabetic microvascular disease.
• Pure motor lacunar stroke:
–Internal capsule, pons, and pyramids.
• Pure sensory lacunar stroke:
– The ventrolateral thalamus or thalamocortical
projections.
• Deficits in consciousness, language, or visual
fields are not seen in lacunar strokes.
Vascular Syndromes
(Vertebrobasilar Artery
Syndrome)
• Occlusions produce a wide variety of symptoms w/ both ipsilateral &
contralateral signs.
• Numerous cerebellar & cranial nerve abnormalities also are present.
• Locked in syndrome (basilar artery thrombosis).
- eyes can not move horizontally only vertically
Altered Consciousness
• Coma or decreased arousal levels may occur w/ extensive brain damage (e.g., large proximal MCA occlusion). • Glasgow Coma Scale is used to document level of coma. • Can be documented as: – Normal, lethargy, obtundation, stupor, and coma.
Nonfluent aphasia (Broca’s/expressive aphasia)
• Slow & labored speech, limited vocab, comprehension is good.
Fluent aphasia (Wernicke’s/sensory/receptive aphasia)
• Speech flows smoothly, difficulty in comprehending spoken language & in following
commands.
Global aphasia
- Impairments of both production & comprehension of language.
- Indication of extensive brain damage.
Dysarthria
• Motor speech disorders.
Dysphagia
• Inability to swallow or difficulty in swallowing (51% of the cases).
Hemispheric Behavioral Differences
Image
Perceptual Deficits
Body scheme/body image
•Unilateral neglect, right left discrimination,
finger agnosia.
Spatial relations
• Position in space, topographical disorientation.
Agnosias
•Visual object agnosia, tactile agnosia
Seizures
• More common right after stroke
during the acute phase
• Small percentage of patients
Bladder & Bowel Dysfunction
• Common during the acute phase (29% of cases).
The National Institutes of Health Stroke Scale (NIHSS) quantifies
quantifies stroke severity based on weighted evaluation findings.
Cerebrovascular Imaging (CT scan)
Readily available imaging
Does not show ischemic changes but would be used to rule out hemorrhagic stroke so you know that they can use thrombolytic or TVA if it is ischemic.
Lowering down the blood pressure would lower the amount of bleeding
Cerebrovascular Imaging (MRI)
• Shows greater resolution of the brain & its
structural detail than does a CT scan.
• More sensitive in diagnosis acute strokes.
– Detects cerebral ischemia as early as 30 minutes
after vascular occlusion.
Medical Management
- Improve cerebral perfusion
- Ischemia-> raise BP
- Hemorrhagic-> lower BP
- Hypotension-> treatment would be to give them fluids
- Maintain integrity of the skin & joints.
Neurosurgical Management
Hemorrhagic stroke: repair a sup ruptured aneurysm or AVM, prevent rebleeding and evacuate hematoma.
Mechanical thrombectomy: remove large blood clot
Carotid endarterectomy: removal of fatty deposits, prevent stroke (after TIA),
- Guidelines: stenosis of 60% to 90%
