Stroke Flashcards
How common is stroke?
- most common cause disability
- 4th leading COD
Lifetime cost of ischemic stroke
$140k
MC type of stroke
87% are ischemic, usually cerebral thrombus
Two types of ischemic stroke
- thrombotic
- embolic
Two types of hemorrhagic stroke
- SAH (in skull around brain)
- intracerebral (in brain)
Four layers of vessel
lumen –> endothelium –> SM –> adventitia
Unmodifiable risk factors for stroke: (5)
- 65+ years old
- african americans
- previous
- female
- family hx
Preventable risk factors for stroke: (7)
- HTN
- DM
- Tobacco
- Afib, carotid disease
- previous
- obesity, inactivity
- hypercholesterolemia
Secondary blood disorders contributing to stroke risk:
- high RBCs
- sickle cell anemia
Genetic risk factors for stroke: (5)
- FV Leiden,prothrombin
- ^ApoE4, homocysteine
- Fabrys
- ED
- Pseudoxanthoma elasticum
Acute Neuroimaging during stroke alert:
1) CT
2) fast brain MRI
3) conventional angio
4) carotid US
5) transcranial dopplers
CTP evaluates for? How?
- core/penumbra
- penumbra has preserved blood volume (CBV)
Define MTT:
- mean transit time
- increased in areas of brain distal to vessel occlusions (penumbra + core)
Define CBV:
- cerebral blood volume
- preserved in penumbra, decreased in core
Compare recanalization of vessels in penumbra v core:
- May be beneficial in penumbra
- risk for more ADRs than benefit in core
Timing for tPA administration
- FDA: 3 hours
- ASA: 3-4.5 hours
ASA dose for stroke pts:
Who recieves ASA?
- 325 mg
- do not recieve tPA
- 24 hours after tPA if no hemorrhage present
When are benefits of tPA seen?
-tPA better than ASA at 90 days out, 24 improvement no different
In addition to 3 hr window + CT free of hemorrhage, what must be true of pt to consider tPA?
- measurable deficit on NIH stroke scale
- patient 18+ years old
What “conditions” are absolute CIs to tPA? (5)
- stroke/ trauma within 3 months
- GI/GU hemorrhage within 21 days
- surgery within 2 weeks
- artery puncture within 1 wk
- history of ICH
What blood pressures are absolute contraindications to tPA?
-185/110 after efforts to manage
What symptoms are absolute contraindications to TPA?
-sx suggestive of SAH even with clear CT scan
What bleding conditions are abs contraindications to TPA?
- heparin + elevated PTT w/in last 48 hours
- PT higher than 15 s
- INR higher than 1.7
Platelet count CI in TPA?
-less than 100k uL
What glucose is abs CI in TPA?
- less than 50
- higher than 400
Four “relative” CI to TPA?
- large/MCA stroke
- sx are minor or rapidly improving
- seizure at onset of stroke
- aggressive tx needed to meet BP goals
FDA approved method of TPA administration
systemic IV dosing
Cushings triad
- HTN
- brady
- irregular respirations
Three symptoms specific of Anterior circulation stroke
- gaze preference
- aphasia
- neglect
Four symptoms specific for posterior circulation stroke
- vertigo
- diplopia
- crossed track findings
- dysconjugate gaze
Four symptoms that may be seen in either anterior or posterior stroke
- hemiparesis, anesthesia
- visual field deficit
- slurred speech
- ataxia
Symptom specific to dominant hemispheric strokes:
1) dominant: aphasia
2) nondominant: neglect, apraxia
Cause of akinetic mutism
Bilateral ACA strokes
Cause of Antons Syndrome + What is antons syndrome
- bilateral PCA strokes
- cortical blindness
mesial temporal lobe infarct affects what structures?
-limbic
MC Cause of AMS assc with stroke
-Aphasias
How common is symptomatic ICH following IV TPA?
6.4% of patients
4 risk factors for ICH following tPA
- older
- previous stroke
- small vessel ischemia
- labile BP
How can emboli reach the brain?
- heart: afib, valve disease, PFO
- carotid stenosis
Visual defect assc with left sided MCA stroke?
- loss of the rt visual fields
- eyes look towards lesion
Speech is controlled by the same side of the brain as:
handedness
right hand dominant, left brain dominant language
3 classic ACA infarct symptoms
- leg more than arm weakness
- personality or cognitive defects
- urinary incontinence
Limb ataxia is assc with stroke of what artery?
-PCA (per master the boards, Kaplan) (per Nolte, can be anterior OR posterior circulation…)
How soon does CT show stroke? MRI? Why is CT done acutely?
- CT: 4-5 days to reach 95% sensitivity
- MRI: 24-48 hrs
- CT done acutely to exclude hemorrhage
What characterizes nonhemorrhagic stroke on CT?
-edema without blood (may see midline shift, ventricular compression)
If ischemic stroke patient is already taking aspirin at time of symptom onset, what is the next best anticoagulant option? (assuming pt is not tpa candidate or has already received is a day ago)
- add dipyridamole
- switch to clopidogrel
Treatment for TIA
aspirin +/- dipyridamole OR clopidogrel
Treatment for hemorrhagic stroke
- none
- may surgically drain only if limited to posterior fossa
If tPA is given within 3-4.5 of sx onset, what is required?
-written consent, this time period is not FDA approved and is considered experimental
In addition to being anticoagulated, every patient with a stroke should take?
STATINS
LDL goal for stroke patients?
-70-100
Appearance of blood on CT
bright white hyperdense lesion
Treatment of thrombi throwing clots to brain:
-heparin –> warfarin
Goal INR for pt with hx of embolic strokes
2-3
How is afib treated to prevent stroke?
-heparin –> warfarin to INR of 2-3
Workout to evaluate causes of stroke?
- echo
- EKG (telemetry, holter)
- Carotid US
When is carotid endarterectomy advised?
70%-90% stenosis
**Cannot intervene is blockage is 100% occluded.
Endarterectomy vs carotid angioplasty and stenting: which is superior?
-endarterectomy, stenting is of no proven value to stroke patients
4 risk factors to control for stroke prevention
- HTN
- keep a1c under 7
- reduce LDL to under 100
- smoking cessation
Definition of TIA
sx resolve within 24 hours
Two main pathways resulting in cellular death from stroke:
- necrosis (energy failure, cell swelling)
- apoptosis (penumbra over days)
PCA #1 defect
-contralateral visual field cut
Signs of lacunar infarct:
-motor/sensory deficit WITHOUT cortical signs
Signs of basilar artery stroke
crossed face and body findings + oculomotor deficits
Signs of vertebral artery stroke
crossed face and body findings + lower cranial nerve deficits
Define: anosognosia
unawareness of illness and its clinical manifestations
similar to insight?
MC cause neglect (2)
-right MCA territory stroke (non-dominant parietal lobe, premotor cortex of frontal lobe)
Why must be determined before diagnosing apraxia
-pt understands the command, is cooperative, and has learned the task
Deficit assc with stroke of dominant occipital cortex/adjacent corpus callosum
agnosia: visual information disconnected from language centers
- patient cannot read own writing, has color agnosia
Define:
- asomatognosia
- prosopagnosia
- asomatognosia: does recognize body as part of own (Mrs. Mayo)
- prosopagnosia: cannot recognize faces
Labs drawn during Stroke Alert (4)
- CBC
- CMP
- PTT
- INR
How long should imaging take during code stroke?
-CT + CTA less than 10 minutes
MRI sequence needed for for assessing stroke?
DWI (intense in stroke)
TPA MOA
-binds fibrin, converts plasminogen to plasmin
How common is hemorrhage in TPA administration?
-6-7%; 1/16
Large artery strokes are often _____ while lacunar infarcts are _____.
large: embolic
lacunar: HTN related
