CVA Intro and Patho Flashcards
Modifiable risk factors for CVA:
i. HTN
ii. Diabetes
iii. CV Disease
iv. Obesity (connected with obstructive sleep apnea)
v. Obstructive Sleep Apnea (hypoxia during sleep)
vi. Physical inactivity
vii. Diet
viii. Blood disorders
ix. Arrhythmias (Atrial fib)
x. Hyperglycemia
xi. Smoking
xii. Alcohol
xiii. Recreational drug use
How can Obstructive Sleep Apnea lead to stroke?
hypoxia during sleep can lead to morning strokes
Non-modifiable risk factors for CVA:
W>M Age: >55yrs Race (black/hispanic) Prior stroke, TIA, and or MI Genetics
Cause of ischemic stroke -
Gradual worsening of fatty deposits lining arterial walls (atherosclerosis)
Two types of ischemic strokes -
- Thrombotic
2. Embolic
Most common type of ischemic stroke -
Thrombotic
Thrombotic stroke caused by what?
Blockage caused by clot form within involved artery
Embolic stroke caused by what?
Blockage caused by clot that travels from elsewhere in circulatory system
Common origins of embolic strokes?
- Heart
2. Larger arteries of upper chest and neck
Embolic ischemic strokes more commonly found in what type of arteries?
Distal and smaller arteries
Cause of hemorrhagic stroke?
- Rupture of artery due to weakening of vessel wall
- atraumatic – spontaneous event
Primary cause of Intracerebral hemorrhage (ICH)?
HTN
Primary causes of subarachnoid hemorrhage (SAH)?
Aneurysm Arteriovenous Malformation (AVM)
Aneurysm -
- enlargement/ballooning of weakened vessel wall
- Typically asymptomatic until rupture
Arteriovenous Malformation (AVM) -
- tangle of abnormal blood vessels connecting arteries and veins (brain and spinal cord most often)
- Congenital: symptoms don’t show up till late teens-30 yrs and some don’t even have symptoms
- Symptoms: seizures, HA, weakness, speech and vision, or can be asymptomatic
What is a Transient Ischemic attack (TIA)?
mini/warning stroke
Causes of Transient Ischemic attack (TIA) -
Not entirely understood:
- Leading hypothesis: temporary blockage that dissolves on its own or gets dislodged naturally
- Cerebral vasospasm and transient systemic arterial hypotension
T/F 10x increased chance for full blown CVA with history of TIA
True, highest risk for stroke in first 90 days post TIA
Describe the steps of ischemic cascade:
- Loss ATP production (loss of aerobic metabolism) followed by increased lactic acid in brain (change in ph)
- Stoppage of Na/K pump
- Excess intracellular Na -> influx H2O = cytotoxic edema (deadly swelling)
- Excess intracellular Ca -> excess glutamate release at axon terminal
- Hyper-excitability cycle transpires throughout nearby neurons =“Excitotoxicity”
- Activates degradative enzymes that breakdown proteins in neuron and cell membrane
- release of free radicals -> neuronal death via necrosis - Breakdown of mitochondria in response to toxins and unstable cell membrane
- Neuronal death via apoptosis (nearby neurons die on purpose)
Infarct core? Time frame?
- primary blood supply (necrosis)
- irreversible damage
- Within minutes
Penumbra? Time frame?
- area surrounding ischemic event
- increase area of cell death -> leads to greater stroke (apoptosis)
- potentially salvageable
- Within hours
History of present illness (HPI) includes what aspects?
- Past medical history/systems review
2. Description of symptoms (onset, type)
Onset of symptoms for thrombotic stroke -
gradual onset, days to weeks
- Most common in late PM or first thing AM, may see “wake up strokes”
Onset of symptoms for embolic stroke -
more abrupt than thrombotic, minutes to hours