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
What causes cryptogenic strokes?
- They account for ___% of all strokes?
- No etiology found
- They account for 10-20% of all strokes
How to determine which anti-platelet to use?
- Aspirin offers benefit over a range of doses
- ASA/ER-DP (Aggrenox) and Clopidogrel (Plavix) have similar safety profiles to aspirin and are slightly more effective than aspirin for stroke prevention but are more expensive
- ASA + Clopidogrel should NOT be used for long-term stroke prevention (no net benefit over ASA alone, and double the risk of hemorrhage)
—- Unless pt is already on 2 antiplatelets for cardiac reasons (i.e. stenting)
What does this show?
Normal pictures of the brain!
What does this show?
CT 6 hrs after ischemic stroke
What does this show?
- 15 min after Ischemic Stroke
(Always good to start by looking for symmetry)
What things appear bright on CAT scan?
- Calcium (bone)
- Thrombi
- Acute blood ?
What does this show? Symptoms?
Massive ischemic stroke
- Affecting left side
What imaging should you use if you suspect a stroke?
Ischemic:
- STAT CT scan if need to be done fast
- MRI with diffusion weighted image
- ADC: advanced diffusion coefficient
What is one of the most important questions to ask someone who you suspect of having a stroke?
When did it happen? When was the last time you felt well?
What is acute treatment for ischemic strokes?
Reopen blocked vessels: “lyse clots”
- IV tPA is a thrombolytic drug proven effective in pts with acute ischemic stroke who present within 4.5 hours of onset of symptoms
- I.A. therapy is chemical or mechanical thrombolytic therapy delivered directly into the thrombosed artery through catheter-based technique; good for up to 6-8 hours
Details of treatment with tPA:
Timeframe?
Outcomes?
Adverse Side Effects?
IV tPA is a thrombolytic drug proven effective in pts with acute ischemic stroke who present within 4.5 hours of onset of symptoms
- Much higher likelihood of complete resolution at 24 hours than placebo
- Much better outcomes at 3 months than placebo
- Odds ratio- benefit from tPA at 30 min is about 3x that of >150 min
- Downside = risk of intracerebral hemorrhage
Case 4
55 year old man with h/o HTN, DM, hyperlipidemia and smoking 1PPD x 20 years presents to ER with 5 HOURS of Left-sided hemi-paresis and neglect of his Left visual field/hemi-space. Urgent CTH is unremarkable
- Localize?
- Treat?
Localized: Right hemisphere
Treat: Cannot give tPA (5 hours after stroke; outside window)
What is the timeframe for treating acute ischemic strokes with I.A. therapy?
6-8 hours
When should you suspect intracerebral hemorrhage (ICH)?
- Deterioration of exam/consciousness
- Severe headache
- Nausea/vomiting
- Acute increase in BP
Diagnosis plan for suspected ICH?
- STAT CT, PT/PTT, CBC, type and cross
- Consider cryo/FFP/platelet transfusion
- Call neurosurgery for evacuation
What is this?
CT scan showing intracerebral hemorrhage
- Blood = bright
- Blood in intraparenchymal space
What are some major causes of PRIMARY intracerebral hemorrhage (ICH)?
HYPERTENSION!
Putamen > thalamus > cerebellum > pons > cortex
Cerebral Amyloid Angiopathy
- Cerebral cortex (lobar)
Age > 80 (typically)
Should surgery be used to treat ICH?
Controversial
- Definite benefit for cerebellar ICH
Treatment of ICH?
- BP control: unclear target (SBP under 160 or maybe 140; MAP 100-110)
- Activated factor VII (no clinical benefit)
- Identify any underlying lesions
- Supportive care
- Rehab! (recovery may take up to 2 years)
What is this?
Subarachnoid hemorrhage
- Blood isn’t as bright as intracerebral hemorrhage
- Most likely caused by rupture of aneurysm
What are some clinical symptoms of Subarachnoid Hemorrhage?
Lab results (imaging, tests)?
Clinical:
- “Worst headache of life”
- With or without focal signs
Lab:
- CT scan detects 90% of SAH
- Angiography to identify vascular anomaly: aneurysm or AVM
Lumbar puncture has better sensitivity and should be performed if CT is negative
- CSF bloody or xanthochromic
What is this?
Basilar artery with aneurysm outpouching
Treatment of subarachnoid hemorrhage?
- BP control
- Angiography to evaluate for aneurysm- early endovascular vs. surgical treatment
- Nimodipine and statin to prevent delayed ischemia
- Supportive care
What is this?
??
