Lecture 4 - Stroke Flashcards
Ischemia vs Infarction
Ischemia - Decreased blood flow (reversible)
Infarction - death of tissue due to lack of blood low
Thrombosis vs embolism
Thrombosis - formation of clot in vessel
Embolism- blot clot travels elsewhere and lodges in smaller vessel
Stroke vs TIA
Stroke - Disruption of blood flow resulting in change in neurological function (lasting more than 24 hours.)
TIA- Transient Ischemic Attack - Usually less than 1 hour, up to 24 hours.
T or F: a TIA will not show evidence on an MRI
T, it is a breif episode of dysfunction in the brain without evidence of an acute infarction on an MRI
When is the highest risk of a stroke after a TIA?
1st 30 days after
90 day risk after a stroke is 3-17%
Those with TIA have an 18.8% strok risk in the next 10 years
What are the categories of the ABCD tool used for evaluating the risk after a TIA ?
Age 60+ - 1pt
Blood pressure 140+ or DBP 90+ 1pt
Clinical features- unilateral weakness or speech impairment - 1 pt
Duration? 60+ minutes : 2 pt , 10-59 mins : 1 pt
Diabetes 1pt
ABCD2 score interpretations?
What is it used for?
0-7
Used to assess risk of stroke after someone had a TIA
7 total points
6-7: high risk of stroke in 2 days: 8%
4-5: Moderate risk of stroke in 2 days: 4%
0-3: Low risk of stroke in 2 days: 1%
What conditions can mimic a stroke?
Hypoglycemia/hypoxia
seizure
migraines
multiple sclerosis attacks
brain tumor/swelling
Why is weakness in both hands or both legs likely not indicative of a stroke
Because it cannot be localized to a single blood vessel
What is NOT an ischemic stroke?
Sudden loss of conciousness (note: this is true for a hemmorhagic stroke)
Pre-syncope/syncope
numbness in both feet
waxing/waning confusion
diffuse weakness
numbness in one and or foot
pain
Stroke is the ___ leading cause of death in the US
Globally it is the __ leading cause of death
5th
2nd
Note: it is the leading cause of serious disability in the US
There has been a decline in stroke mortality over past decades
What are considered modifiable risk factors for stroke
Hypertension
Diabetes
High Cholesterol
Heart disease
Smoking
Drug Abuse
Pregnancy
OCP(oral contraceptives)
Alcohol
Obesity
Physical Activity
Sleep Apnea
Nonmodifiable risk for stroke
Older age
Male
Family History
Race (Blacks > Whites)
Most strokes are :
Ischemic (87% of stroke)
note: 25-30% have undetermined etiology
An ischemic stroke will appear ______-dense on a CT
Hypo-dense
A hemorragic stroke will appear as _____dense on a CT scan
Hyperdense
Most ischemic strokes are ________, the second most common is ________
Undetermined Etiology
Small Vessel Disease
Of all thrombotic infarctions, –% had a warning episode
50%
Note: Thrombotic infarctions ofen happen during sleep, pt awakens w/ deficit
MCA infarctions mainly affect the ______
Hemiparesis of contralateral face/arm
MCA strokes can cause aphasia if which side of the brain is affected?
The dominant
If an MCA stroke happens on the _______ side, your neglect is more significant
Non-Dominant side
MCA strokes can cause _____ sensory loss and homonymous hemianopsia
Cortical
MCA strokes can cause a loss of conjugate gaze to the _____ side
Opposite side
(trouble looking away from the weak side)
Aphasia often starts as _______ and turns into only wernickes or broca’s aphasia overtime
Global Aphasia
The anterior MCA supplies what language area?
Posterior MCA?
Broca’s
Wernicke’s
ACA strokes (rare) will cause deficits where?
Leg > arm
ACA can cause urinary incontinence usually only w/
bilateral infarcts
PCA infarcts often cause what?
Homonymous hemianopsia
visual hallucinations
cortical blindness
inability to read (alexia)
Ischemia of Which cerebral artery can cause problems w/ motivation/organization behaviors
ACA
Symptoms of vertebrobasilar ischemia
Sensory/motor abnormalities in face/extremities
vertigo/clumsiness/ataxia
diplopia/dysarthria, dyphagia
nausea/vomiting
hearing loss/hiccups
Basilar strokes can cause cranial nerve problems on the _________ side and weakness in the body on the _______
Ipsilateral side
Contralateral
cerebral emboli arise in the heart from:
Mainly atrial Fibrillation
myocardial infarction
akinetic segment
endocarditis
How will a cardioembolic stroke appear on an MRI?
Diffuse throughout bran
_____(heart condition) can increase stroke risk x5 and x2 increase risk of death
but ____________ therapy can reduce the risk of stroke by 2/3
A fib
Oral anticoagulation therapy
What is Warfarin (coumadin)
An oral anticoagulant used to treat a-fib
3 places an embolic infarct can come from?
Aorta
Large intracranial arteries
Patent foramen ovale
What is a “lacunes”
What are they usually related to/caused by?
They typically affect what structures?
Small artery occlusion
hypertension/diabetes
Putamen/caudate/internal capsule/thalamus/corona radiata, pons
What are the classes/classic symptoms of lacunar infarctions
Pure motor:
Pure sensory:
Sensorymotor:
Dysarthria+ clumsy hand syndrome:
Ataxia-Hemiparesis:
Pure motor - Hemiparesis (Internal capsule base of pons)
Pure sensory stroke- (Posterolateral thalamus) - note: think dorsolateral column for sensory
Sensorimotor stroke: Thalamus + internal capsule (anything motor includes internal capsule)
dysarthria and clumsy hand syndrome: base of pons
Ataxia-hemiparesis - Pons + Internal capsule or subcortex
+ Thalamic strokes cause ____________ sensory loss to all modalities
+ They may develop what syndrome?
+ Mild hemiparsis
Contralateral sensory loss
May develop Thalamic pain syndrome
Hearing loss, facial weakness, ataxia, horner syndrome
What (artery) stroke can cause these?
AICA
PICA/Vertebral artery strokes can cause ______ syndrome
Lateral medullar/wallenberg syndrome
ipsilateral ataxia and scanning/explosive speech
Strokes of what artery can cause this?
Superior Cerebellar artery
What are rare causes of a stroke
Inherited disease
inflammatory disorders
hematologic disorders
What are the 6 steps to approaching a patient w/ an acute stroke?
- _______
- Categorize _______
- Determine _______
- Calculate ________
- Determine ________
- Determine ______
Stabilize patient
Categorize as ischemic vs hemorrhagic
Determine last known normal
Calculate NIHSS score
Determine if theyre a candidate for acute thrombolytics
Determine if theyre a candidate for endovascular intervention
What is the goal of door to needle time
(time they enter hospital to time they get clotbuster (TPA)
45 mins
note: the standard time is 60 mins
For every ______ delay in TPA administration, there is a 10% decline in probability of a good outcome
30 min delay
What is the most important aspect of the history of someone who’s had an acute stroke?
Time of onset
11 Categories to the NIHSS
Conciousness
Best gaze- horizontal eye movemnent
visual field- determine if there’s hemianopia or blindless
Facial palsy - ask them to make faces
Motor (arm)- ask them to raise arms
Motor (leg)- ask them to raise leg in supine for 5 seconds
Limb Ataxia - check finger to nose
Sensory- use safety pin
Language
Dysarthria
Extinction/neglect
What is the only FDA approved medicine for acute strokes?
TPA
Tissue plasminogen activator
Contraindications for TPA:
_____ hours from last known normal
hemorrage
head trauma or stroke in last 3 months
severely high BP
Endocarditis
Bleeding disorder
High Glucose 50+
4.5 hours from last known normal
T or F: TPA has no benefit to mortality of acute strokes
T
No benefit to mortality
However it does increase the likelihood of a good outcome within 3 months
For patients who have received TPA, BP must be measured ____________ for the first 24 hours
Check every 15 mins for first 2 hours
every 30 mins for first 6 hours
Every hour for next 18 hours
Patient’s who have taken TPA need to maintain a bloodpressure of what?
Under 180/105, however it’s suppose to be high, its bad if it’s low or normal
BP goal for patient w/ TPA vs without?
With TPA: 180/105
Without? 220/110
Why? Because we want the higher BP in order to reestablish perfusion to the ischemic areas
If a patient is worsening after receiving TPA what should the medical team do?
Repeat imaging
keep BP up
Keep patient supine
NO PT
May do craniotomy to reduce swelling
What is a carotid endarterectomy?
Surgical procedure to remove plaque build up from carotid artery
An ischemic stroke on a DWI will appear :
An ischemic stroke on an ADC will appear:
Light area on DWI
Dark area on ADC
On a DWI, a new stroke will appear as a :
An old stroke will appear as a:
New stroke: Light hyperdense area
Old stroke: Dark hole
The highest rate of recovery for a stroke is seen when?
1st 3-6 months
but can have improvement (small) for several years
What abilities usually recover quicker after a stroke?
Swallowing/facial movements/ gait
note: recovery tends to begin proximally
What abilities recover more slowily after a stroke?
Language, spatial attention, dominant hand movement
What are signs of an intracranial hemorrhage?
Very rapid onset
Intracranial pessure symptoms: Headache, vomiting, decreased conciousness
CT scan will show blood fast
T or F, you can tell an ischemic and hemorrhagic stroke apart using a physical exam
F
U need imaging
What are the causes of an intracerebral hemorrhage?
Most common?
Most common: Hypertension
Trauma
Rupture of Arteriovenous malformation
aneurysm
tumor
hemorrhagic conversion
Common locations of an intracerebral hemorrhage?
Putamen, cerebral hemisphere, thalamus, cerebellum, pons
A higher score on the glasgow coma scale means what?
More conscious
note: 3 is minimum score
How to treat intracerebral hemorrhage?
Treat intracranial pressure (Craniotomy/ectomy)
Intubate
reversal of antiplatelet or anticoagulation
Aggressive BP management
80% of subarachnoid hemorrhage are caused by what
Rupture of intracranial aneurysm
Note: 10% die b4 medical attention
40% die in 3 months
50% of survivors have disabilities
Symptoms of aneurysm rupture?
Sudden explosive headache
loss of conciousness
stiff neck/light sensitivity
nausea/vomiting
Note: 50% of patients have a warning leak with more subtle signs b4 a rupture
What kind of stroke is the leading cause of death and disability
Aneurysmal subarachnoid hemorrhage
How can vasospasm from a hemorrhage lead to an ischemic stroke?
The blood irritates the smooth muscles of vessels and leads to vasospasm
Signs of a venous stroke?
Headache
Focal neurological signs
Hemorrhage
Altered mental state/seizures
Diagnose w/ CT or MRI
Who does a venous stroke usually occur in?
Pregnant woman/ women on birth control
