Vascular Disease Flashcards
What is the adult prevalence of aneurysms?
What is the annual incidence of aneurysmal SAH?
Adult prevalence: 2%
Annual incidence aSAH: 0.006-0.008%
What are modifiable risk factors for aneurysmal SAH?
HTN, smoking, alcohol abuse
What percent of patients with aSAH die before reaching the hospital? What percent die by one month?
Before hospital: 10-15%
One month: ~50%
What are the major morbidities associated with aSAH?
Rebleeding, Vasospasm, Hydrocephalus, Seizures, Cardiac complications, Hyponatremia
With aneurysms <7mm in size without a previous SAH what is the approximate 5 year risk of bleeding for each of the below categories:
Anterior circulation
Posterior circulation
Carotid Cavernous
Anterior circulation: 0%
Posterior circulation: 2.5%
Carotid cavernous: 0%
After reaching approximately what size do carotid cavernous aneurysms start to have an appreciable risk of rupture over 5 years?
> 13mm
13-24mm: 3.0%
>24mm: 6.4%
What is the 5 year risk of rupture of a posterior circulation aneurysm 7-12mm in size?
14.5%
much larger risk than anterior circularion, 2.6%, and carotid cavernous, 0%, risk
What is the approximate risk of rupture of aneurysms > 24mm in size in the following locations:
Anterior circulation
Posterior circulation
Carotid Cavernous
Anterior: 40.0%
Posterior: 50.0%
Carotid cavernous: 6.4%
PHASES
Describe the categories of the Hunt-Hess Grading Score
I: Asymptomatic/minimal headache, nuchal rigidity
II: Moderate to severe headache, nuchal rigidity, +/- focal cranial nerve palsy
III: Drowsy, confused, mild focal deficit
IV: Stuporous, hemiparesis, +/- early decerebrate rigidity
V: Deep coma, decerebrate, moribund
The grading schema designed by Hunt and Hess was designed for determining risk of what?
Risk for vasospasm after aSAH
I and II: 20-30% risk
III and IV: 50% risk
V: 75% risk
Describe the WFNS systems for grading aSAH?
I: GCS 15 and no deficit II: GCS 13-14 and no deficit III: GCS 13-14 and deficit IV: GCS 7-12 +/- deficit V: GCS 3-6 +/- deficit
Describe the Fisher radiographic grading scale for determining risk of vasospasm
I: No hemorrhage
II: Diffuse SAH with vertical laters <1mm thick
III: Localized clots and/or vertical layers >1mm thick
IV: With ICH or IVH
*Incidence of vasospasm is highest in grade III
How are dissecting aneurysms managed depending on location?
If extracranial then antiplatelet/anticoagulation to reduce risk of ischemia
If intracranial then surgical or endovascular obliteration
How do pseudoaneurysms typically form?
Often sequela of trauma (penetrating > blunt).
Hematoma from an arterial rupture forms in between outer walls of artery and can even lead to carotid cavernous fistula
Relative to saccular or fusiform aneurysms, where are infectious/mycotic aneurysms more often located? What other condition are they associated with? What is first line treatment?
Distally located
Bacterial Endocarditis
Antibiotics (~ 6 weeks)
What was the major finding of the International SAH Trial (ISAT)?
ISAT found that endovascular coiling is a good option compared to surgical clipping in aSAH.
At one year 31% of patients clipped were dead or dependent compared to 24% in the coiling arm
What may be a good general rule of thumb for the type of surgical treatment most amenable to anterior, middle, and posterior circulation aneurysms respectively?
Anterior: Variable between clipping and coiling
Middle: Clipping
Posterior: Coiling
What surgical approach is often most helpful for anterior, middle, and posterior circulation aneurysms?
What may need to be done for distal anterior cerebral aneurysms?
Pterional craniotomy
Anterior interhemispheric approach for distally located anterior circulation aneurysms
What are the typical presentations for AVMs in order of most common symptoms?
Hemorrhage (50%)
Seizures (25%)
Headache, focal deficits from steal phenomenon
What features of AVM are associated with increased risk of hemorrhage?
Hemorrhagic original presentation, large size, deep venous drainage, associated aneurysms
What are the three categories involved in the Spetzler-Martin grading system for AVMs and the points involved?
Nidus size:
<3cm - 1
3-6cm - 2
>6cm - 3
Eloquence of adjacent brain:
No - 0
Yes - 1
Venous drainage pattern:
Superficial - 0
Deep - 1
What are the treatment options for AVMs?
Medical mgmt (e.g. antiepileptics)
Embolization
Radiosurgery
Surgical resection
If opting to use radiosurgery for an AVM is there still a hemorrhagic risk? What features of AVMs make them more amenable to radiosurgery?
Yes, in the 2-3 years post-radiosurgery before complete obliteration there is still risk of hemorrhage
Small nidus (<3cm) near eloquent brain or with deep venous drainage
What Borden grade for dural AVFs generally warrant treatment?
Borden II and III due to 15% annual event rate
What is the major goal in the treatment of dAVFs?
Elimination of cortical venous reflux (CVR)
Borden I dAVF
Dural venous drainage with no cortical venous reflux
Borden II dAVF
Dural venous drainage WITH cortical venous reflux
Borden III dAVF
Cortical Venous reflux only
How does the Cognard grading scale differ from the Borden scale for dAVFs?
Cognard scale separates dural venous drainage into anterograde and retrograde drainage.
For Borden grade III, Cognard scale distinguishes between cortical venous reflux +/- venous ectasis
What if often preferred for dAVF treatment, transarterial embolization or transvenous coiling?
Transvenous coiling
What are the peaks for age of presentation with Moya-Moya disease?
Age 3 and 20-30s
What is the typical presentation of Moya-Moya disease and how does it differ with the age of presenation?
In pediatric cases more often presents with ischemia (80%)
In adult cases more often presents with hemorrhage (60%)
CCM1-3 are autosomal dominant conditions placing patients at heightened risk for what vascular condition?
Cavernous malformations
How do cavernous malformations often present?
Seizures, focal deficits, headaches
Hemorrhage may occur and is more common in deeper lesions and in the posterior fossa
What are appropriate treatments for cavernous malformations?
Medical mgmt/observance for seizure control
Surgical removal is often very effective
Radiosurgery usually doesn’t alter their natural history
What are risk factors for ICH?
Age > 60, EtOH use, HTN, amyloid angiopathy, drugs (e.g. cocaine), coagulopathy
Above what ICH hematoma volume does prognosis steeply drop off?
> 30cc
ICH score
What measures should be taken for initial medical mgmt of ICH?
Strict BP control (varies on center, at UPMC SBP goal <140 and can later be liberalized to <180)
Correct coagulation
Manage ICPs and frequent neuro exams
How does the mgmt of a cerebellar ICH differ from a lobar or even basal ganglia hemorrhage?
Need to be prudently watched because if there are signs of neurologic deterioration, brainstem compression, or obstructive HCP then urgent evacuation may be needed
What are the most common areas for hypertensive ICH to occur?
Basal Ganglia
Thalamus
Pons
Cerebellum
What is the major concern for morbidity after a large stroke (e.g. MCA territory or cerebellar)?
Post-infarct edema which may cause obstructive HCP or malignant edema
In patients developing malignant edema after an infarct what is the appropriate management for:
Cerebellar territory infarcts
MCA territory infarcts
Cerebellar: craniectomy and possibly strokectomy
MCA; Hemicraniectomy can be done but has severe morbidity; outcomes are better in younger patients and in nondominant hemisphere strokes
According to the NASCET trial, symptomatic stenosis greater than what percentage is associated with a 17% absolute risk reduction after two years if operated on with CEA compared to medical mgmt?
70-99% stenosis
Symptomatic carotid stenosis between 50 and 69% warrants what treatment?
NASCET shows very mild absolute risk reduction at 5 years with CEA (6% ARR)
Horner syndrome (miosis, anhidrosis, ptosis) in a young female may be due to what pathology?
Carotid dissection
What is the main treatment for patients with extracranial arterial dissection?
Antiplatelet/anticoagulate agents for 6-12 weeks
What is the main treatment for patients with intracranial arterial dissection?
Antiplatelet/anticoagulate for 6-12 weeks (unless SAH part of presentation)
Surgical options: proximal clipping, vessel reconstruction, endovascular stenting
How are carotid-cavernous fistulas characterized?
High-flow (e.g. cavernous carotid aneurysm rupture)
Low-flow (e.g. dural carotid branch, ECA, etc.)
How do carotid-cavernous fistulas present?
Pulsatile proptosis, retro-orbital/orbital pain, chemosis, ocular bruit, visual deterioration, diplopia
Why is it that low-flow CCFs can be medically observed?
~50% thrombose on their own
(Medically managing is ok as long IOP < 25mmHg
What interventions serve as useful for the management of CCFs which failed medical management?
Endovascular transarterial embolization
Endovascular transvenous coiling
Coagulation cascade inhibition
Coagulation cascade
Hemostasis labor
cerebral infarction MR signaling
When compared to DWI (Diffusion-Weighted Imaging), ADC (Apparent Diffusion Coefficient) is a complementary MRI technique that provides additional information about tissue microstructure. While DWI measures the random motion of water molecules, ADC calculates the rate of diffusion in multiple directions. ADC is particularly useful for evaluating white matter integrity, detecting Alzheimer’s disease, and differentiating between tumor types. In MR imaging, ADC and DWI are often used together to provide a more comprehensive understanding of tissue characteristics and abnormalities.
carotis stenosis measuring
The minimal lumen diameter is divided by the diameter of the distal ICA where the walls become parallel so as to avoid any post-stenosis dilatation
coagulation cascade (again)
carotid endarterectomy risks and benefits
Carotid endarterectomy
(1) Asymptomatic stenosis of 60–99% has a 6% absolute risk reduc-
tion for stroke over 5 years if operative mortality < 3% and if the patient has a 5-year life expectancy
(a) stroke risk of untreated asymptomatic stenosis is 2% per year
(2) Symptomatic stenosis of 70–99%
has a 17% absolute risk reduction for stroke over 2 years if operative mortality < 6% and if the patient has a 5-year life expectancy
(a) Stroke risk of untreated symptomatic stenosis is 13% per year
(b) Benefit of surgery persists for less than 1 year after stroke or TIA; therefore, surgery is best done as soon as possible after a stroke (usually within 4 to 6 weeks when the risk of stroke is highest)
(c) 50%–70% symptomatic stenosis may also benefit from surgery in
(i) Male patients
(ii) Conjunction with plaque ulceration
(iii) Cases involving nonlacunar hemispheric stroke or TIA
(d) Endovascular stenting is a treatment option for carotid ste-
nosis in patients who are poor surgical candidates
amyloid angiopathy
Amyloid angiopathy:develops when fibrillary proteins form a β-pleated sheet conformation that deposits in the walls of arterioles as amyloid, causing wall thickening and lumen narrowing; amyloid deposits can extend into the surrounding perivascular tissue, resem-
bling senile plaques of Alzheimer disease
(1) Histology: similar to lipohyalinosis except that amyloid angiopa-
thy is congophilic (i.e., exhibits apple-green birefringence after Congo red staining) whereas lipohyalinosis is eosinophilic (i.e., stains with hematoxylin)
(2) ICH from amyloid angiopathy often extends into an SAH because of the cortical location of the ICH (3) Genetics: most cases are sporadic and involve the amyloid pre-
cursor protein (APP) (i.e., the amyloid β-protein 1-42 [Aβ1-42]) that is found in Alzheimer plaques
(a) Rare hereditary forms of amyloid angiopathy
(i) Icelandic-type amyloid angiopathy: mutations of cys-
tatin C, a protease inhibitor that accumulates as amyloid when mutated; causes fatal ICH by 20–30 years of age
(ii) Dutch-type amyloid angiopathy: mutations in APP that cause accumulation as amyloid; causes fatal ICH by 40 years of age
(iii) Mutations of transthyretin, the thyroxine (T4) carrier protein
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL
Pathophysiology: a systemic vascular disease of smooth muscle; caused by autosomal dominant mutations of the Notch 3gene on chromosome 19, the protein of which acts as a cell-cell adhesion molecule with nuclear transcription regulatory properties
I. Transcription regulatory properties require cleavage of the Notch 3 protein by γ-secretase and transport to the nucleus
ii. Notch 3 protein in the cell membrane binds the delta ligand on neigh-boring cells
iii. Notch 3 gene is located very close to the CACNL1A4gene that is mutated in familial hemiplegic migraine
(1) Sporadic mutation in 15% of patients with characteristic MRI ab-
normalities and no family history
b. Histology: fibrosis of the tunica adventitia and granular deposits in the tunica media that develop in arteries of 100–400 mm in diameter (penetrating arteries)
i. Deposits are of an unknown composition that is not amyloid
ii. Deposits surround the smooth muscle cells, and also occur in muscle and skin arteries in some patients
c. Symptoms: onset between 30–50 years of age
i. Recurrent lacunar stroke and TIA, often occurring in the thalamus and sparing the cortex
ii. Dementia (30%): usually develops > 10 years after the first stroke from a combination of multiple strokes (i.e., a vascular dementia) and progressive leukoencephalopathy
iii. Migraine with aura (25%): does not develop in childhood like other migraines, and typically involves fever and/or stupor {confusional migraine (see pg. 154)}
iv. Mood disorders: develop early in the disease course
Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS
Pathophysiology: caused by point mutations in a transfer ribonucleic acid (tRNA) encoded by the mitochondrial genome; exhibits maternal inheritance
i. Highly variable penetrance dependent on the number of affected mitochondria
b. Symptoms: usually presents in childhood
i. Stroke, particularly in the occipital region and frequently in a distribution that is not defined by a single artery
ii. Migraine, often occurring at the time of a stroke
iii. Vision loss from retinopathy; sensorineural hearing loss
iv. Diffuse weakness from myopathy
v. Seizures and dementia, which develop during adolescence
c. Diagnostic testing: lactic acidosis; ragged-red fibers on muscle biopsy
d. Treatment: B-complex vitamins + niacin + coenzyme Q10; dichloroacetate
Infectious endocarditis
Infectious endocarditis: causative organisms are Streptococcus viridans, Staphylococcus aureus, Enterococcus»_space; HACEK organisms (Haemophilus, Acinetobacillus, Cardiobacterium, Eikenella, Kingella), fungi
i. Risk factors include IV drug abuse (usually causes right-sided endo-
carditis) and cardiac abnormalities (e.g., artificial heart valves)
ii. Infectious endocarditis leads to an infectious arteritis, which pro-
gresses to
(1) Mycotic aneurysm formation on the distal superficial cerebral arteries
(2) Microabscess formation
(3) Meningoencephalitis
Aneurysm wall histology
Fibromuscular dysplasia
a. Pathophysiology: smooth muscle hyperplasia and fibrosis of small- and medium-sized arteries (renal > cervical > visceral > extremities); variants of the disease can involve hypertrophy of the tunica intima or adventitia
i. A non-inflammatory condition that does not involve atherosclerosis or vascular calcification but that is associated with the development of cerebral aneurysms
ii. Involvement of the extracranial carotid and vertebral arteries is much more common than involvement of the intracranial vasculature
b. Epidemiology: usually occurs in middle-aged women
c. Symptoms: ischemic stroke (30%); hypertension from renal artery stenosis; limb claudication; bowel ischemia
d. Diagnostic testing: angiography demonstrates alternating segments of constriction and dilation (string of beads sign, tubular stenosis)); rarely, arterial dissection develops at sites of disease
e. Treatment: antiplatelet agents or anticoagulation; surgical relief of obstruction in high-grade lesions
watershed infarctions sites
Arteria disscetions
carotid injury occurs with compression against the transverse process of vertebrae during neck extension and rotation; vertebral injury occurs with stretching between C1 and C2 vertebrae during neck rotation
Dissection locationi. Carotid artery: usually within 2–3 cm of the bifurcation; rarely en-
ters the petrous bone or extends intracranially
ii. Vertebral artery: generally starts around C1 or C2 vertebral level and often extends intracranially
Antiplatelet anticoagulation drugs
(1) Aspirin: absolute risk reduction for recurrent stroke = 1% (a) Irreversibly inhibits cyclooxygenase production of thromboxane that causes platelet aggregation, but also inhibits vasodilatory prostacyclin production
(b) Low-dose (e.g., 81 mg qd) or enteric-coated aspirin will inhibit platelet aggregation in only 40% of patients, in comparison with 70% of patients taking higher doses or uncoated aspirin, but higher doses are not known to be better for stroke prevention
(2) Dipyridamole + aspirin (Aggrenox): modestly better than aspirin alone; higher side-effect rate, particularly headaches
(a) Dipyridamole reduces platelet aggregation by *inhibiting cyclic adenosine monophosphate (cAMP)-phosphodiesterase *and by blocking adenosine reuptake
(3) Ticlopidine: seldom used; used for patients who cannot tolerate aspirin; has a higher side-effect rate (diarrhea, neutropenia, thrombotic thrombocytopenic purpura)
(a) Reduces platelet aggregation through a poorly understood mechanism
(4) Clopidogrel:equivalent efficacy against stroke in comparison to aspirin; benefit of clopidogrel over aspirin is its superior protection against myocardial infarction in selected patients
(a) Reduces platelet aggregation by blocking adenosine diphosphate (ADP) binding to adenosine receptors
(b) Same side-effect profile as ticlopidine; fewer hemorrhagic side-effects in comparison with aspirin
(5) Warfarin: 67% relative risk reduction for stroke from atrial fibrillation when International Normalized Ratio (INR) is 2–3
(a) For mechanical heart valves, target INR of 3–4; for bioprosthetic heart valve, target INR of 2–3
(6) Dabigatran: direct thrombin inhibitor; indicated for stroke pre-vention in non-valvular atrial fibrillation
(a) Requires dosing according to renal function
(b) Has a lower rate of hemorrhagic complications than warfarin
(7) Heparin: no proven benefit in stroke management; used commonly as a bridge to warfarin therapy and for temporary management of unstable major artery stenosis prior to surgical or endovascular intervention
(a) Side effects: heparin-induced thrombocytopathy (HIT) syndromes, cauased by a decreased number of platelets and platelet malfunction
(i) Type I HIT: develops < 5 days after starting heparin and is clinically benign; heparin causes platelet aggregation, thereby increasing blood viscosity
(ii) Type II HIT: develops 1–2 weeks after starting heparin and is associated with arterial and venous thromboses; heparin-induced autoantibodies cause thrombocytope-
nia but also a paradoxical hypercoaguable state
Reverse anticoagulation
(1) For patients on warfarin, use
(a) 2–3 units fresh-frozen plasma; titrate to normalization of coagulation measures, which may require up to 6 units
(b) Vitamin K 10 mg IM: takes 12 hours to have any effect
(2) For patients on heparin, use protamine 1 mg per 100 units of heparin administered
(3) For patients on dabigatran, no reversal agents are available; plasma clotting factor administration or hemodialysis may reduce drug levels
Aruba study critics
vascular supply of brain
blood supply of the brain coronal view
blood supply of basal ggl
AChA
AChA 2
memory
PCA
PCA infarct
cisterns
Antoni Babisnki sy
Anton-Babinski syndrome, also known as ABS or Anton syndrome, is visual anosognosia, or denial of vision loss, associated with confabulation, or making up experiences to compensate for memory loss, in the setting of cortical blindness.
Spinal AVM types
type I: dural AVF.
type II: intramedullary glomus AVM.
type III: intramedullary juvenile AVM.
type IV: perimedullary AVF.
type V: extradural AVF.
dAVF, IM g, IM j, PM, ED
spinal AVM feeders
Fistula type (I) and nidus type (glomus II) spinal AVM difference
Patients with nidus-type AVMs were younger at presentation and more often presented with hemorrhage, with a higher proportion of hematomyelia than fistulous-type AVMs (P<0.05). Progression of clinical presentation from hemorrhage to congestive myelopathy during follow-up was noted in 5 patients, all of which had AVMs of the nidus type. Complete obliteration could be achieved more often in the fistulous type (72%) than in the nidus type (27%). Improved or stable clinical status at last follow-up was noted in 100% of fistulous-type and 77% of nidus-type patients. Long-term clinical deterioration was noted in 6 of 26 patients with nidus-type (23%) AVMs and was related to recurrent bleeding (n=3) or progressive venous congestion (n=3). Overall rebleed rate after presentation with hemorrhage was 7 in 145.5 patient-years (4.8%/y) if the lesion was not treated, 3 in 102 patient-years (2.9%/y) after partial treatment, and 0 in 47.5 patient-years (0%) after complete treatment.
Clinical Features and Outcomes of Spinal Cord Arteriovenous Malformations: Comparison Between Nidus and Fistulous Types
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