Cerebrovascular disease and stroke Flashcards
what is the definition of a stroke
a neurologic deficit attributed to an acute FOCAL injury of the CNS by a VASCULAR CAUSE, including cerebral infarction, intracerebral hemorrhage (ICH), and subarachoid hemorrhage (SAH)
what is a ischemic stroke
blood clot stops the flow of blood to an area of the brain
what is a hemorrhagic stroke
weakened/diseased blood vessel rupture - blood leaks into brain tissue
What are common stroke symptoms
sudden neurological deficit:
Vision, Speech,Sensory, Motor, Impaired coordination/balance
non-specific - AMS, confusion, dizziness, vertigo, headache, lightheadedness, memory impairment
what are vision changes in a stroke
diplopia, visual field cut
What are speech changes in a stoke
asphasia, dysarthria, dysphagia
what are sensory changes in a stroke
one-sided numbness/altered sensation
what are motor changes in a stroke
one-sided weakness
what are non-sepecific symptoms associated with stroke
AMS, Confusion, dizziness, vertigo, headache, lightheadedness, memory impairment
what are stroke risk factors
smoking, sedentary lifestyle and an unhealthy diet, air pollution, HTN, obesity, hyperglycemia, hyperlipidemia
sleep apnea, DVT/PFO, Atrial septal defect, Arterial dissection, hyper-coagulability, sicks cell, autoimmune disorders, contraceptives, pregnancy, PCOS, binge drinking, poor nutrition, cocaine and amphetamine use
what is the first branch of the internal carotid artery
Opathalmic artery
how do you differentiate between the internal and external carotid arteries
The external carotid has many branches and branches early and the internal carotid has less branches and delayed branching
what is the definition of ischemic stroke
an episode of neurological dysfunction caused by focal cerebral, spinal or retinal infraction.
Time based definition: >24 hours of neurological deficit
Radiographic definition: MRI needed
what are special cases of ischemic strokes
MRI-negative strokes: infarcts can be missed on MRI. stroke is ultimately a clinical diagnosis
Silent Strokes: imaging/pathological evidence of infarction without history of acute neurological dysfunction attributable to the lesion
What is the TOAST classification
classification of stroke by mechanism or cause:
Large-artery atherosclerosis (embolus/thrombosis)
Cardioembolism
small-vessel occlusion
Stroke of other determined etiology
stroke of undetermined etiology
what is cardioembolic
when a clot forms in heart and then travels to the brain (common in afib, cardiomyopathy and MRI)
what is a lacunar infarction
a small vessel stroke
infarction following atherothrombotic or lipohyalinotic occlusions
what is hypoperfusion
also known as borderzone stroke
decreased global blood flow (hypotension, heart failure, hypovolemia) can stress the most distal reaches in a vascular territory
what is a paradoxical embolism
a patent foramen ovale (PFO) acts as an open window to allow venous clots to bypass the lungs and enter the arterial pathway to the brain.
what needs to be identified in regards to paradoxical embolism
need to identify source of embolus, eg DVT to implicate it in stroke
what is stroke syndrome
pattern of deficits you will (may) see when a specific arterial territory in the brain is affected
what is aphagia
inability to effectively communicate
What are the classic lacunar syndromes
Pure motor hemiparesis
pure sensory stroke
sensorimotor
ataxic hemiparesis
dysarthria clumsy hand
how many neurons die per minute during a stroke
2 million per minute until reperfusion is achieved
what is the ischemic core
brain tissue destined to die
what is penumbra
salvageable brain area (the shadow)
what is early thrombolytic/thrombectomy aimed at
rescuing tissue in the penumbra
what is key to establish during a stroke alert
Last Known Well Time (which is NOT the same as first seen abnormal)
what strokes are typically not eligible for thrombolytics or thrombectomy
“wake-up” strokes
what makes patients contraindicated for TPA treatment
hemorrhagic strokes
what is the initial stroke used to determine
hemorrhage vs not- hemorrhage to determine treatment (tPA or not)
what does the MRI assess for
necrotic brain tissue
what is the hyperacute phase of ischemic stroke treatment
tPA if within < 4.5 hours of symptom onset
what does tPA do
breaks down thrombus
what is the benefits of tPA
therapeutic benefit of tPA is greatest when given very early and declines throughout the first 4.5 hours after onset
reduced mortality
reduced symptomatic intracranial bleeding
higher rates of independent ambulation at discharge
higher rates of discharge to home
how many patients see improvement with tPA
1 out of every 3 patients
what is the risk of tPA
hemorrhage
what are the current inclusion criteria for tPA
diagnosis of ischemic stroke causing measurable neurologic deficit
onset of symptoms < 3 hours before beginning treatment
Aged greater than or equal to 18 years
what are the exclusion criteria for tPA treatment
history of head trauma/prior stroke in pervious 3 months
aterial puncture at noncompressible
intracranial tumor/mass
elevated BP
active internal bleeding
blood glucose
what test is required prior to tPA treatment
CT and blood glucose stick
what are relative exclusion criteria for tPA treatment
minor/rapidly improving stroke symptoms
pregnancy
seizure at onset
major surgery/trauma within past 14 days
over the age of 80
severe strokes
what does LVO stand for
Large vessel occlusion
What has the greatest benefit of treatment for LVO
tPA and thrombectomy
what are key questions during stroke work up
where is the lesion?
What is the mechanism (etiology)?
what are the key parts of stroke initial evaluation
History and physical exam
quick, focused stroke scale
CT (rule out bleed/structural abnormality)
Labs
MRI
vessel imaging
echocardiogram
EKG
special labs
rhythm monitoring
what is the mainstay long-term treatment of stroke
antiplatelets (aspirin, clopidogrel, etc), high intensity statin
When is DAPT used
short term after severe intracranial stenosis or after high-risk TIA or minor stroke
not helpful long term or if initiation is delayed >2wks
what is DAPT
dual-antiplatelet therapy
what is the efficacy of aspirin
best when given early, may reduce Severity of early recurrent stroke
~17% risk reduction over 3 years
what is the efficacy of Anticoagulation in Afib
warfarin ~66% effective in reducing stroke, possibly superior
what is the efficacy in high intensity statins
~20% risk reduction
what is the most important factor in treating a stroke
Risk factor management
over 80% risk reduction
what are common post stroke complications
stroke deficits (vision, speech, sensorimotor, balance/gait)
seizures, aspiration pneumonia, pressure ulcers, urinary retention/incontinence
pain syndromes, cognitive impairment/dementia, falls/fractures, emotional/psychological impact, relationship/family stress
anxiety/dression
what are the 10 warning signs of stroke
- confusion
- difficulty understanding
- dizziness
- loss of balance
- numbness
- severe headache
- trouble speaking
- trouble walking
- vision changes
- weakness
what does BEFAST stand for
Balance
Eyes
Face
Arm
Speech
Time
how many strokes are recurrent
1 in 4 strokes are recurrent
how do you modify risk factors
control BP
control cholesterol
control your blood sugar
discontinue smoking
reduce/stop drinking alcohol
exercise at least 30 minutes daily
eat a heart-healthy diet
What is a TIA
transient ischemic attack - episode of temporary and focal neurological dysfunction of vascular origin, which are variable in duration, commonly lasting from 2-15 minutes.
They leave no persistent neurological deficits
how do you differentiate between TIA and stroke
TIA has no evidence of infarct on brain imaging
what is the minimum treatment for TIA
anti-platelet agent plus statin
plus control of blood pressure, blood sugar and other risk factors
what is the ABCD2 score used for
risk stratification for TIA
Age
Blood pressure
Clinical features
Duration of symptoms
Diabetes
what is a hemmorrhagic stroke
caused by intraparenchymal hemorrhage: rapidly developing clinical signs of neurological dysfunction attributable to a focal collection of blood within the brain parenchyma or ventricular system that is NOT CASUED BY TRAUMA
what is the definition of silent cerebral hemorrhage
a focal collection of chronic blood products within the brain parenchyma, subarachnoid space, or ventricular system on neuroimaging or neuopathological examination that is not caused by trauma and without a history of acute neurological dysfunction attributable to the lesion
how is ICH categorized
medical emergency
what is the management of ICH
treat the cause
rapid head CT (or MRI) to distinguish ischemic stroke from ICH, aneurysmal SAH
give platelets if thrombocytopenic
if on coumadin with elevated INR, reverse with vitamin K/K-centra
acute BP lowering
ICU monitoring
what is an asymptomatic aneurysm
unruptured - usually asymptomatic, unless they are large and causing symptoms from mass effect and compression on adjacent structures
what is the prognosis of a ruptured aneursym
fatality up to 60%
what is the pathophysiology of aneurysms
congenital/FH
atherosclerosis
HTN
genetic abnormalities
vasculopathies/inflammation
arteriovenous malformations
CT disorders
infections
sickle cell disease
trauma
neoplasms
cigarette smoking
illicit drug use
alcohol
what are the primary cerebral aneurysms
Saccular, fusiform, mycotic and giant aneurysm
what is a saccular aneurysm
also known as berry aneurysm - bulges from one side of an artery, A neck leads to it.
what is a fusiform aneurysm
bulges from all sides of an artery - it rarely has a neck
what is a giant aneursym
can involve more than one artery. it is over 2.5 cm wide
what is a mycotic aneursym
caused by infected artery wall. this type is fairly rare.
what is the main cause of mycotic aneurysms
endocarditis
what are the most common locations of aneurysms
ACA, PCOM, branches of the MCA and top of the Basilar artery
what are the common signs and symptoms of aneurysms
incidental finding/asymptomatic
minor aneurysmal hemorrhage with mild symptoms (fever, N/V, sweating, chills)
catastrophic - aneurysmal subarachnoid hemorrhage (SAH) - “worst headache of my life”, AMS, seizure, focal deficit due to mass effect or secondary ischemia
SAH is caused by what
rupture of the aneurysm
- filled with blood causing sudden, intense headaches - sometimes described as “worst headache of one’s life”
what is required if CT does not r/o SAH and there is a strong suspicion
do a lumbar puncture - xanthochromia (blood in the CSF) develops after 6 hours
What does the modified Fisher Scale have benefit for
determining vasospasm risk
what are complications of aneurysmal SAH
recurrent bleeding
hyponatremia
paroxysmal sympathetic hyperactivity
seizure
hydrocephalus
vasospasm
what is the clinically applicable aneurysmal SAH scale
Hunt and Hess Scale - for prognosis
what are the surgical treatments for aneurysms
clipping and coiling
coiling is used more frequently than clipping or ligation
what are medication treatments for aneurysmal SAH
Nimodipine (calcium channel blocker to reduce vasospasm)
+/- antihypertensive
osmotic agents if welling present
antiepileptics
pain/fever control
stool softeners
Where is a subdural hemmorrhage
collection of blood in the subdural spaece - usually the result of head trauma
what is the presentation of subdural hemorrhage
shear damage to the bridging cortical veins as they cross the dura mild or indolent symptoms
how do you distingush a subarachnoid hemorrhage
cortical shaped
arterial blood
how do you distinguish a subdural hemorrhage
crescent shaped, venous blood - located in the potential space between the dura and arachnoid matter
what is the presentation of extradual hemorrhage
blood collection between the skull and the dura - associated with head trauma/skull fracture
how do you distinguish a extradural hemorrhage
lens shaped (higher pressure)
arterial blood does not cross sutures
what is GCA
giant cell arteritis
inflammatory vasculitis
what is the serious complication of GCA
irreversible vision loss
what is GCA linked to
polymyalgia rheumatica
what is the SSX of GCA
sudden or insidious onset
+/- prodrome anorexia, weight loss, fever, night sweats
headache
PMR pattern (shoulders, neck, hips/thighs)
fatigue/malaise
jaw claudication
fever
vision changes
eye motion abnormalities
what are differential diagnosis for GCA
acute angle closure glaucoma
herpes zoster
iritis/uveitis
tia/stroke
migraine
how is GCA diagnosed/worked up
labs (CBC, ESR, CRP, LFTs)
standard of care: emergent temporal artery biopsy
non-invasive imaging (ultrasound, MRI/MRA)
what is the treatment of GCA
high dose steroids (at least prednisone 60mg)
best within 24 hours
duration of steroids can be up to 2 years
can also use low-dose aspirin, proton pump inhibitor, bisphosphonates, calcium and vitamin D for bone protection)
