stroke Flashcards
stroke
occurs when the blood supply to part of the brain is suddenly interrupted or when a BV in the brain ruptures
how long does it take for cerebral edema to reach its maximum
72 hours and takes about 2 weeks to subside
arterial occlusion (ischemic)
thrombus-clot in situ
embolus-loose clot
rupture of blood vessel (hemorrhagic stroke)
arterial defect or trauma
non-modifiable risk factors for stroke
heredity age (increases with age) gender- women ethnicity- AA previous stroke or TIA
modifiable risk factors
HTN Heart disease DM (control of BP contributes to prevention more than blood sugar) smoking alcohol viscosity of blood
how long do TIA’s last
less than 24 hours
- most last 5 minutes
what are residual ischemic neruo deficits
reversible ischemic events lasting more than 24 hours
pathophys of TIA
in situ platelet agg or showering of tiny emboli–> blockage of circulation or vasospasm caused by releases of vasoactive substances
what is the prognosis of TIA is not treated
80% will have recurrance
prediction of stroke within 48 hours of a TIA
"ABCDD" scoring system Age (greater than 60) BP (140/90) Clinical features (weakness, speech) Duration of TIA symptoms (greater than 60 2 points) Diabetes
risk assessment after scoring
6-7= 8% risk
use as a warning to the patient to let them know they need to change their habits/lifestyle
subtypes of ischemic stroke
thrombotic
embolic
lacunar (special subtype)
other..
hypotensive
vasospastic
various and sundry
thrombotic due to large vessel disease
- includes both extracranial and intracranial blood supply to the brain (athero-thrombosis most comomon)
thrombotic due to small vessel disease
-involves smaller penetrating arteries of the brain that can result in small, deep infarcts referred to as lacunar infarcts or subcortical strokes
(lipohyalinosis)
features of a thrombotic stroke
- proceeded by TIA
- during sleep
- step wise progression “stroke of evolution”
- completed stroke- CVA that has completed its progress and has resulted in some amount of permanent,irreversible damage to the brain tissue
what is the role of an early brain CT?
r/o intracranial bleeding, abscess, and tumor
signs of carotid artery disease
- transient monocular blindness (TIA of ophthalmic artery)
- hemispheric deficit
lacunar disease
associated with chronic HTN, DM, hyperlipidemia
- can occur indepen or concurrently with large vessel cerebrovascular disease
- can be due to disease in estuaries of the internal carotid artery or in the vertebrobasilar artery distribution
lacunar (subcortical) stroke
- associated with vascular lesions in the posterior circulation (vertebral and basilar) resulting in cranial nerve impairment or dysfunction of the motor an sensory tracts
signs of vertebrobasilar arterial disease
horners syndrome
syndromes related to lacunar stroke
pure motor pure sensory sensorimotor ataxic-hemiparesis clumsy hand dysarthria multi infarct dementia
prophylactic treatment of lacunar strokes
aspirin has not been show to prevent
-most effective treatment s to manage risk factors
cardiac causes of embolic stroke
- a.fibb
- MI
- endocarditis
- rheumatic heart disease
- valvular prostheses
- ASD/VSD “paradoxical embolism”
