Stroke 1 Flashcards
(47 cards)
Brain is __% of the body weight
Brain uses __% of cardiac output
Brain uses __% of total body oxygen
2% of body weight
Uses 15% of CO
Uses 20% of total body oxygen
What arteries supply the anterior and posterior portions of the brain?
Anterior 3/5th supplied by internal carotid.
Posterior 2/5 (cerebellum, brainstem) supplied by the vertebral arteries that join to form the basilar arteries.
Why are neurons primarily aerobic?
They need O2 and glucose.
They don’t store glucose- they require continuous supply of glucose and O2.
Few minutes of ischemia= irreversible injury.
Subdural vs epidural hematoma
Subdural: Bleeding into the space between the dura mater and brain itself
Epidural: Bleeding into the space between the dura mater and skull.
What happens in the brain if oxygen and glucose levels are low?
Oxidative stress.
Ischemia causes mitochondrial disfunction.
Excess glutamate causes cell death
Excess intracellular calcium causes cell death.
ROS causes mitochondrial disfunction.
Transient Ischemic Attack
A brief period of inadequate cerebral perfusion. Sudden focal loss of neurologic function.
*Rapid onset and resolution. Less than 5 mins of duration. Usually followed by full recovery within 24 hours.
Transient loss of blood flow, but no permanent damage
Difference between TIA and mini stroke
TIA: Transient loss of blood flow, but no permanent damage
Mini stroke: small strokes with permanent defects
*TIA possible causes
*Intermittent vessel obstruction- clots/thromboses, plaques
temporary vasospasm due to drugs, stress, smoking, or migraines.
*___% of patients who have TIA will have a full blown stroke if left untreated within 1 year
35%
TIA symptoms
- Paresis in arm, legs, or face.
- *Diplopia
- *Transient vision loss, amaurosis fugax
Vertigo, loss of speech, loss of understanding, loss of balance
TIA distinguishing symptoms of non-TIA events
*Speed of onset. Fast, not slow! lightheaded Tightness in the chest Stomach upset History of similar epodes where TIA was ruled out
TIA workup
Main:
Carotid auscultation, carotid ultrasound, echocardiogram.
Additional: CTA, MRA, lab work, ECG
Stroke defintion
Disturbance of blood supply causing loss of brain function. More severe than TIA by definition.
Permanent disturbance/damage to neurons.
Stroke is #__ cause of death in US
5. #6 world wide
High risk population for stroke
Older adults
African americans, american indians, alaska natives
Low level of education
Southeastern US
Stroke risk factors
*****HTN
*Diabetes
Obesity
Heart disease
Atherosclerosis
High cholesterol
Smoking
Previous stroke or TIA
2 types of stroke
Ischemic, Hemorrhagic
Ischemic stroke is what percentage of all strokes and what is the mortality
80-85% of all strokes
40% mortality
Hemorrhagic stroke is what percentage of all strokes and what is the mortality
15-20% of all strokes
Mortality is 80%
What is the most common cerebral artery affected by CVA? What percentage of strokes?
Middle Cerebral artery
50-75% of strokes
8.5% of strokes are due to posterior cerebral artery
Ischemic stroke is primarily due to blood vessel occlusion. What 4 things causes this?
Thrombotic (35%)
Embolic (30%)
Lacunar (20%)
Dissection (5% due to carotid and vertebral)
Ischemic stroke is due to which two things?
Primary: Blood vessel occlusion.
Secondary: Systemic hypofusion. Pump failure and hypovolemia. (hypovolemia can lead to shock)
Most at risk areas for ischemic stroke
Watershed areas. These are most distal areas supplied by arteries. Minimal overlap of blood supply. Location is between major arteries- border zones.
Embolic stroke due to which main two things?
Artery/vein thrombosis
Plaque fragments from carotid arteries
