6/19- Clinical Evaluation of Cerebrovascular System Flashcards
__ cause of permanent ____
Stroke is the #__ COD in the US?
Stroke is the #3 COD in the US
#1 cause of permanent disability
(>50% of all hospitalizations for acute neurological diseases)
What is a stroke (def)?
Sudden focal neurological deficit with a vascular cause
Types of stroke? Percentages?
- Ischemic (lack of blood flow) = 80%
- Hemorrhagic = 20%
Risk factors for stroke?
Non-modifiable
- Age
- Sex
- Race-ethnicity
- Heredity
Modifiable
- Hypertension
- Cardiac disease (AFib)
- Diabetes
- Hypercholesterolemia
- Cigarette smoking
- Excessive alcohol
- Physical Inactivity
Symptoms of stroke?
- Weakness
- Aphasia (loss of ability to speak or understand speech)
- Visual loss
- Numbness
- Vertigo
- Double Vision
- Imbalance
- Incoordination (FAST- face, arms, speech, time)
Subtypes/mechanisms of ischemic stroke?
- Cardioembolism
- Large vessel atherosclerosis
- Small vessel lipohyalinosis
- Rare causes: hypercoagulable state, vasculitis, dissection, other
- Cryptogenic/idiopathic
Risk factors for Cardioembolic stroke?
- Mechanical valve
- Atrial fibrillation
- Thrombus: LV, LAA, aortic arch
Others:
- Recent MI (under 4 wks)
- Akinetic LV segment
- Atrial myxoma
- Endocarditis (infective vs. marantic)
- Sick sinus syndrome
- Cardiomyopathy
- Low Ejection Fraction
- PFO
Case 1:
91 year old man previously healthy “playing golf daily” presents to the ER after he was found down this morning. Last seen normal yesterday afternoon.
Meds include aspirin only.
BP is 120/85 in the ER, pulse 137, RR 12, O2=99%, afebrile.
On close exam, you notice his pulse to be irregularly irregular and he is aphasic with Right-sided hemi-paresis.
Cardiac enzymes are negative in the ER
- Localize?
- Cause?
- Treat?
- Localize: right-sided cortical problem
- Cardioembolic/ischemic stroke
- Treat with anti-coagulation
Anti-coagulation treatment with what?
Mechanism?
Goal?
Warfarin (Coumadin)- proven to work for cardioemboli
- Target INR of 2.5 (2.0-3.0) if pts can “tolerate”
Treatment for atrial fibrillation (1’ and 2’ stroke prevention)
- Warfarin
- Aspirin
- Dabigatran (Pradaxa): direct thrombin inhibitor [RE-LY study showed lower rates of stroke and systemic emboli but equal rates of major hemorrhage]
- Rivaroxaban, apixaban: similar to dabigatran
Where is large vessel atherosclerosis commonly seen?
Extracranial
- Common Carotid Artery (CCA)
- Internal Carotid Artery (ICA)
- Vertebral Artery
Intracranial
- Internal Carotid Artery (ICA)
- Middle Cerebral Artery (MCA)
- Anterior Cerebral Artery (ACA)
- Basilar Artery (BA)
Case 2:
75 year old man with h/o HTN, DM, hyperlipidemia and smoking 2PPD x 50 years presents to the ER with 2 days of Left-sided hemi-paresis that has not gotten better.
He denies heart disease, palpitations, CHF, or syncope.
Meds include aspirin, insulin, ACEI, low-dose statin.
BP is 140/85 in the ER, pulse 77; LDL=190 and HbA1c=9% checked weeks ago.
On close neurologic exam, you notice he also has neglect of his Left visual field/hemi-space with a bruit on the right
- Localize?
- Cause?
- Treat?
- Localize: Cardioembolic stroke affecting the carotid
- Cause: Extracranial carotid stenosis (picture)
- Treat: Carotid endarterectomy (CEA)
Effectiveness of Carotid Endarterectomy (CEA)?
As narrowing lessens, efficacy decreases as well
- NASCET study
- 70% stenosis and above probably deserves surgical intervention
Indications for carotid stenting?
- Recurrent stenosis after endarterectomy
- Post-radiation stenosis (XRT)
- Surgically inaccessible disease (neck anatomy)
- Poor operative candidate
What is small vessel lipohyalinosis?
- Small infarcts (under 15 mm)
- “Lacune”
Often occur in subcortical structures of the brain:
- Internal capsule
- Basal ganglia
- Thalamus Occlusion of lenticulostriate arteries
Many are clinically silent
Rare Causes of Stroke (5%)
- Dissections
- Vasculitis: drug use (cocaine), syphilis, HIV
- Genetic disorders: Sickle cell, Fabry’s, CADASIL
- Hypercoagulable states: anti-phospholipid Abs, protein C, S, Antithrombin III deficiency, Factor V Leidlen, Pregnancy and oral contraceptives, Polycythemia, Myeloproliferative disorders
Case 3:
25 year old woman previously healthy presents to the ER with 2 weeks of Left-sided hemi-paresis and vision changes. She denies any medical problems, but does have chronic neckaches after she had a car accident after she left Busch Gardens and was on the rollercoaster all day. She saw a chiropractor but the symptoms haven’t improved. No Meds.
BP is 110/78 in the ER, pulse 67.
On close neurologic exam, you notice she also has Horner’s syndrome.
- Localize?
- Caused by what?
Localization: right cortex
Cause: Dissection caused by trauma
- Keys here are MVA, roller coaster, and neck manipulation