NSB231 Chapter Notes - Chapter 54: Transient Ischemic Attack, Subarachnoid Hemorrhage, Intracerebral Hemorrhage
Chapter 54: Stroke
PATHOPHYSIOLOGY
• The brain needs continuous supply of blood to provide the oxygen and glucose needed to keep
the neurons functioning.
• A stroke occurs when there is an interruption in the blood supply resulting in brain cell death
• Blood is supplied via the internal carotid arteries and the vertebral arteries
• Factors that affect blood flow include:
• ↑ BP
• ↑ Cardia Output
• Blood Viscosity (thickness)
RISK FACTORS OF STROKE
• Best way to decease is through prevention
• Non-modifiable
• age, gender, race and heredity
• Modifiable
• Hypertension, cholesterol, smoking, excessive alcohol consumptions, obesity, inactivity, diet
and drug abuse
• Atrial fibrillation, cardiac valve abnormalities and diabetes
TYPES OF STROKES
• Ischaemic Stroke (inadequate blood supply)
1. Transient ischaemic attack (TIA)
- passing episode of neurological dysfunction caused by focal brain, spinal cord or retinal
ischemia without infraction of the brain.
2. Ischaemic stroke
-inadequate blood flow to the brain from partial complete blocking of an artery.
- accounts for 80% of all strokes
• Thrombotic stroke
- occurs from injury to a blood vessel wall and formation of a blood clot. Lumen of blood vessel
narrows, becoming for susceptible to blockage.
- extent depends of rapidity of onset, size of lesion and presence of collateral circulation.
- Lacunar stroke refers to a stroke resulting from the blockage of small penetrating arteries
that proide lood to the rain’s deep structures.
• Embolic stroke
- occurs when an embolus lodges in and blocks a cerebral artery, resulting in infraction and
oedema.
- prognosis is dependent on the amount of brain tissue deprived of blood.
3. Haemorrhagic Strokes (blood vessel burst/leak)
- Haemorrhagic stroke: results from bleeding into the brain tissue or into the subarachnoid
space.
- Intracerebral haemorrhage: bleeding within the brain caused by a ruptured vessel. Sudden
onset. Poor prognosis.
- Subarachnoid haemorrhage: occurs when there is intracranial bleeding into the
cerebrospinal fluid-filled spae. 55% don’t surie.
SIGNS AND SYMPTOMS OF STROKE
Related to location of stroke
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Document Summary
Chapter 54: stroke: the brain needs continuous supply of blood to provide the oxygen and glucose needed to keep the neurons functioning. Risk factors of stroke: best way to decease is through prevention, non-modifiable, modifiable, hypertension, cholesterol, smoking, excessive alcohol consumptions, obesity, inactivity, diet age, gender, race and heredity and drug abuse, atrial fibrillation, cardiac valve abnormalities and diabetes. Ischaemic stroke (inadequate blood supply: transient ischaemic attack (tia) Passing episode of neurological dysfunction caused by focal brain, spinal cord or retinal ischemia without infraction of the brain. Inadequate blood flow to the brain from partial complete blocking of an artery. Accounts for 80% of all strokes: thrombotic stroke. Occurs from injury to a blood vessel wall and formation of a blood clot. Lumen of blood vessel narrows, becoming for susceptible to blockage. Extent depends of rapidity of onset, size of lesion and presence of collateral circulation.
