Cerebrovascular Disease Flashcards
What is the primary cause of ischemic cerebrovascular disease?
Atherosclerosis
Risk factors: smoking, diabetes, hypertension, hyperlipidemia, positive family Hx
Where in the cerebral vasculature does atherosclerosis build up?
Bifurcation points or large, major cervical or intracranial arteries
Define “transient ischemic attack”
A reversible, focal neurological deficit lasting 24 hours or less (typically 10-20 minutes)
What is the cause of a TIA?
Temporary obstruction of a large artery by an embolus (from an arterial or cardiac source)
Define “amaurosis fugax”
monocular blindness
Painless, temporary loss of vision in one eye
Name two types of neurologic deficits caused by a carotid artery TIA
Amaurosis fugax
aphasia, hemiparesis (hemispheric syndromes)
Name three types of neurologic deficits caused by a vertebrobasilar TIA
Homonymous hemianopsia (due to visual cortex involvement)
ataxia, diplopia (typical of by brain stem/cerebellar syndrome)
Differentiate causes of amaurosis fugax and a scotoma
Amaurosis fugax: cholesterol emboli in retinal arterioles with occlusion of superior temporal arteriole
Scotoma: infarction of inferior retina
Define ischemic infarction
a persistent, focal neurologic deficit from an arterial occlusion which may improve over time
Occlusions of large vessels affects which part of the brain?
The cortex
Occlusions of the small vessels affects which parts of the brain?
The subcortex – suggested by lacunar syndrome
What four cardiac abnormalities can lead to a cardiac embolus –> stroke? Which is the most common
Atrial fibrillation–> most common
Valvular lesions
Right to Left shunt (Patent foramen ovale[ transmits venous clots)
Myocardial infarction
Name a vasoactive recreational drug that leads to a hypercoagulable state
cocaine
What are the important steps in the evaluation of a TIA or infarction?
1) MRI/CT to both confirm the vascular territory involved and to rule out any atypical presentation of a tumor, hemorrhage, abscess or encephalitis
2) Diagnostic testing to identify the source/cause of the infarction/embolus etc
What three things need to be evaluated following an infarction/TIA of large vessel (therefore involving the cortex)
- Vascular evaluation- Carotid ultrasound or MR/CT angiogram or a conventional angiogram to look for vascular occlusion
- Echocardiography- r/o or r/i cardiac sources of emboli
- Test for hypercoagulability/drug screens etc
What is the cause of a lacunar infarction?
thrombosis of atherosclerotic lenticulostriate arteries due to HTN, diabetes or older age (or hypercoagulable state)
Generally NOT due to embolism- they don’t lodge here.
A lacunar infarct in the internal capsule, pons, or corona radiata leads to what three clinical syndromes?
- Pure motor hemiplegia
- Ataxic-Hemiparesis
- Clumsy hand- dysarthria (Dysarthria-clumsy hand syndrome is characterized by the combination of facial weakness, severe dysarthria, and dysphagia, with mild hand weakness and clumsiness
A lacunar lesion in the thalamus leads to what type of clinical syndromes?
pure sensory stroke
Patients can receive IV tPA for a stroke if they present within how many hours of the onset?
3 hours
What class of drugs is generally given to a stroke patient to prevent recurrence?
Anti-platelets
aspirin, clopidogrel, dipyridamole
What is a carotid endarterectomy and why might it be done following a stroke?
Vascular procedure- clear the carotid artery of atherosclerotic plaques
It is done in cases where the flow is limited >70% through the cervical internal carotid artery and is causing symptoms.
What drugs are given to prevent further cardiac emboli (especially in the presence of atrial fibrillation?)
Anticoagulants such as warfarin, heparin
What symptoms differentiate an infarction from hemorrhage?
Severe headache with early impairment of consciousness
- atypical for infarction
Does hemorrhagic blood originate from veins, arteries, or both?
Higher pressure arteries
