Neurology: Strokes Flashcards
What are 3 potential genetic risk factors for stroke?
Apolipoprotein E4
Elevated Homocysteine levels
Factor V mutation (clotting cascade)
What is the biggest risk factor for stroke?
Hypertension
What are the two general mechanisms of stroke?
- Ischemic: atherothrombotic/embolic, cardioembolic, small vessel disease
- Hemorrhagic: intracerebral, subarachnoid
What is the mechanism of a cerebrovascular atherosclerotic stroke?
Plaque builds up in a cerebral blood vessel (or carotid). The plaque becomes rough and platelets collect along the plaque and eventually form a clot. The clot stenoses the vessel.
What is the #1 risk leading to a cargiogenic embolus-induced stroke, and what is the mechanism?
Atrial Fibrillation
-this condition does not allow proper emptying of the blood from the atria in the heart. The blood is allowed to pool in the atria and it clots and breaks free forming an embolus. The embolus then travels up to the brain or may even get caught earlier causing the stroke.
Infective endocarditis is another source of an embolus that can lead to a stroke. How is this treated?
Treat the infection.
You do not give clot busters or any anticoagulants due to increased risk of bleeding. Plus the infection will keep causing clots and other heart issues.
What is a sign on CT that a patient has suffered a stroke from a heart issue like atrial fib?
Multiple sites of infarct will be visible in different vascular territories.
Method of treatment for a patient that has a stroke due to an air embolus.
Hyperbaric chamber to relieve pressure in the vessels of the brain.
What is the definition or common presentation of patients with a TIA?
A brief episode of neurological dysfunction caused by focal brain or retinal ischemia with symptoms lasting less than one hour, and without evidence of acute infarction.
Patients present to PCP explaining a focal neuro deficit that “comes and goes”.
What are common symptoms of TIA resulting from a carotid stenosis vs. a vertebrobasilar stenosis?
Carotid: unilateral weakness or numbness
- Aphasia if on the dominant hemisphere
- transient monocular vision loss (amaurosis fugax)
VB: bilateral weakness, numbness, vision loss
-brainstem issues like diplopia, vertigo, ataxia, dysphagia
How can a physician tell if a TIA is due to a thrombus or an embolus?
Thrombus: multiple similar events like facial numbness that comes and goes over and over.
-slow and progressive
Embolus: multiple dissimilar events like facial numbness, then hand numbness, then to trunk numbness.
- seizures w/ sudden onset
- specific focal deficit
How can a patient be asymptomatic with an Internal Carotid Occlusion?
Some people have a very well developed circle of willis that allows a lot of collateral circulation. A blocked internal carotid territory can be aided by the other side in these people.
Others may not have as well developed vasculature and may present with severe stroke symptoms.
Review: the internal carotid artery officially continues as what vessel from the circle of willis?
Middle Cerebral Artery
What are the major symptoms of a patient with an Anterior Cerebral Artery occlusion?
- hemiplegia and/or hemianesthesia of the leg more than face or arm
- urinary symptoms
- apathy (if frontal lobes are affected)
What are the major symptoms of a patient with a Middle Cerebral Artery occlusion?
- Hemiplegia and hemianesthesia of the face and arm more than leg
- homonomous hemianopia
- aphasia (if dominant hemisphere is affected)
Describe Broca Aphasia.
Nonfluent, repetition impaired, comprehension spared.
Can’t produce speech but can understand it and follow directions
Describe Wernicke Aphasia.
Fluent, impaired comprehension, repetition impaired, gibberish
Patients can speak but cannot comprehend
Describe Conduction Aphasia.
Lesion in the arcuate Fasciculus (area containing peri-sylvian connections between Broca and Wernicke)
-patient has difficulty with repitition. They cannot read out loud.
Describe Global Aphasia.
Usually caused by MCA occlusion and all aspects of speech are affected. Both Broca and Wernicke are affected.
What symptoms result from a posterior cerebral artery occlusion?
- Homonomous hemianopia
2. Hemiplegia or hemiparesis (due to thalamus or cerebral peduncle affected)
What are lacunar infarcts?
Small vessel disease: occlusion of tiny branching vessels in the brain. Usually have very focal symptoms like: pure motor, sensory, pseudobulbar palsy etc. Usually occur in the white matter areas.
Biggest risk factor for Small vessel disease.
Hypertension
How is taking oral contraceptives while smoking a risk for stroke or small vessel disease?
The combination increases coagulability and formation of clots.
Describe Weber Syndrome (in the depth Dr. Esper wants us to know).
Midbrain stroke resulting in:
- CN III palsy
- contralateral hemiplegia
Describe Wallenberg Syndrome (in the depth Esper wants us to know).
Occlusion of vertebral artery or PICA resulting in:
- ipsilateral facial numbness
- ataxia
- Horner Syndrome
- dysphagia, hoarsness, loss of taste
- contralateral loss of Pain and Temp