stroke Flashcards
def. acute stroke
- sudden loss of brain function
- interuption of blood flow
- loss of O2 and glucose to brain
- ischemic of hemmoragic
def. TIA
self-limited episode of neuro dysfunction
- not associated with cerebral infarction
biggest risk for stroke
age
- stroke rate doubles each decade after 55
how has aging and deaths due to strokes changed over time
age of pop going up, but deaths going down (better care)
how will this change in future
interventions will plateau and deaths up again
impact of stroke
1% of canadians
3% of heath $
how are stroke and TIA localized
to a single vascular territory
2 keys to understanding stroke localization
- 4 major arterial territories
2. understanding underlying anatomy
what is origin of all cerebral blood supply
A arch
2 main branches
- internal carotid
2. vertebral
3 main vascular territories and the supply vessels
- brainstem
- basilar and vert. arts. - cerebellum
- PICA
- AICA
- SCA - main cerebral
- MCA
- ACA
- PCA
2 deep brain structures and what supplies them
- basal ganglia - MCA and perf.
2. thalamus - top of basilar and PCA perforating
what is ACA territory and effect of ischemia
- medial frontal and parietal lobes
- contralateral hemiparesis and anathesia- leg more
what is MCA territory and effect of ischemia
supply: lateral frontal and parietal + superior temporal
ischemia:
- contralateral hemiparersia and anasthesia face, arm>leg
- contra homonymous hemianopsia
- conta hemineglect and ipsi gazw deviation
- lagnuage impairment if on dominant side
what is PCA territory and effect of ischemia
supply - inferior temporal and occipital
ischemia
- contraleteral homonymous hemianopsia
what is basilar territory and effect of ischemia
supply - pons and midbrain
ischemia
- tracts to contrlateral
- nuclei to ipsilateral
what is brainstem territory and effect of ischemia
- both tracts and nuclei - crossed face/body deficits
what are 2 cerebellar syndromes
- vermis (central) - gait ataxia and truncal instability
2. lateral - ipis limb ataxia
what is effect of small vessel
- perfuse deeper structures
- result in small discrete lesions causing classic syndromes
lacunar affects of internal capsule, basal ganglia
all contra
- pure hemi-motor
- pure hemi- sense
- hemi sensimotor
- ataxic hemiparesis
- dysarthia/clumsy hand syndrome
lacunar thalmic effects
contra sensory loss
mech of ischemia
insufficient blood flow leading to irreversible damage
4 main etiologlies of ischemia
- thrmobosis
- embolism
- hemmorage
- hypoperfusion
def. thrombosis
formation of clot or throbus in artery - triggered by pathological endothelium
most common location of atherscleosis causing stroke
internal carotid
def. embolsim
formation of clot in another area that breaks off and travels to brain
2 common sources of embolism
- artery-to- artery - atherosclerosis
2. cadiac to artery - A fib, valvular disease
2 common causes of hemm
- uncontrolled or spike in HT
2. amyloid angiopathy - weakens vessel walls
proportion of stroke etiology
hemm 12-15% , rest is ischemia
2 main ischemia etiologies
- atheroscleoris - 45%
2. cardiogenic - 20%
modifable risk factors
- HT
- diabetes
- hyperlipid
- smoking
- obesity
- sedentary
diet
CAD - heart disease
non-modifiable risk factors
- ages
- male
- fam Hx
- genes
most important modifiable risk factor
HT
what are HT targets
140/90 or 130/80 for diabetes
what is blood target in diabetes
A1C
2 treatments of lipids and their effects
fibrate - reduce chol, but no effect on stroke
statins - reduce LDL and most effective
what is effect of statins
- 25% RRR
- each 10% redcuction in LDL = 13% reduction in stroke
what are primary and secondary targets for stroke prevention
primary - framingham
secondary - LDL
what is major cardiac risk factor
A fib - more severe strokes
what is use of anticoag
reduces stroke risk in A fib
what to use for anticoag
warfarin - 66% RRR
ASA - 19%
what is doing of warfarin
keep INR @ 2-3
what is advantages to new anticoags
- no INR to monitor
- standard dosing
- need good renal funct
what is risk of TIA
high risk for stroke in next 90 days
5 things to do after TIA
- treat HT
- start statin
- screen for diabetes
- antocoag
- lifestyle mods
what to do to prevent thrombus formation
antiplatelets - ASA
- absolute benefit small
- but cheap and minimal adverse effects
what is standard dose of ASA
anything over 30mgis good - standard is 81
2 other options
- aggrenox
2. plavix
what is first and second line anitplatelet therapy
1st - ASA
2nd - plavix daily or aggrenox BID
- used if had stroke or TIA on ASA
2 treatments for carotid disease
- endartectomy
2. stent
when to do endartectomy
stenosis > 70% - any time will benefit
50–59% - need to do in 2 weeks
what is diff. between endartectomy and stent
no diff up to age 70, then end is better
what is time for thrombolysis
4.5H of stroke onset
