Extra Cranial Flashcards
Arterial palpation
Common carotid : bifurcation Superficial temporal Subclavian: above/below clavicle Axillary Brachial: antecubital fossa
Bruit
Abnormal sound heard on auscultation caused by turbulent flow.
Bruit that’s no longer heard could mean progressed to >90% diameter reduction
Hemorrhagic Stroke
Bleeding in brain. Blood vessel bursts in brain causing damage to brain tissue. Most common cause: HTN
Ischemic Stroke
MC type. 3rd leading cause of death.
80% thrombo embolia with carotid MC source.
Interruption of blood supply to brain causing decrease in oxygen to brain. MC cause: blood clot/emboli. MC factor: atherosclerosis.
Lacunar Stroke
Obstruction of small perforating arteries that supply deep areas of brain. MC: elderly diabetic or poorly controlled HTN
Transient Ischemic Attack TIA
Few mins to no more than 24 hours.
Symptoms: unilateral and contralateral •amaurosis fugax (monocular blindness-black shade coming into eye) (ipsilateral) •dysphasia/aphasia: impaired language •contralateral hemiparesis •abnormal behavior
MC: emboli that is non flow limiting stenosis
Reversible Ischemic Neurologic Defect RIND
Symptoms last more than 24 hours. Patient reverts back to normal.
Symptoms: unilateral and contralateral except for eye (ipsilateral) •amaurosis fugax (ipsilateral) •dysphagia/aphasia: impaired language •contralateral hemiparesis •abnormal behavior
Vertebrobasilar insufficiency
Flow obstruction in posterior circulation.
Temporary
Symptoms usually bilateral. •ataxia: inability to coordinate muscle activity •drop attacks •vertigo: dizzy •bilateral visual disturbances •dyplopia: double vision
Cerebrovascular Accident CVA
Complete Stroke with permanent and lasting neurological deficit.
Symptoms:
•dysphasia/aphasia: lose ability to understand speech. Impaired language.
•hemiparesis
•death
•miscellaneous neurological defects: facial droop, loss of vision
Risk: Diabetes mellitus HTN Smoking Hyperlipidemia
Atherosclerosis
A form of arteriosclerosis (when arteries become thick and stiff, restricting blood flow)
Atherosclerosis: buildup of fat, cholesterol, substances in artery walls. Disease or intima,íntima proliferation (hyperplasia), deposition of fatty substances and luminal reduction
Risk: diabetes, HTN, hyperlipidemia, smoking, age, gender, family hx, hypercoagulopathy
Types of atherosclerotic plaque
Fatty streak: homogeneous thick layer of lipid material on intimas layer.
Fibrous (soft) plaque: homogeneous accumulation of lipids, collagen, and elastic fibers.
Complicated lesion: heterogeneous, bright echoes with shadowing fibrous plaque that include collagen, calcium, and cellular debris.
Ulcerative: deterioration of smooth fibrous plaque. May shed debri that embolizes.
Abnormal intimal thickening = _____ mm
0.9mm or more
Hemodynamically significant stenosis :
area of lumen is reduce 75%
Or a 50% diameter reduction
Diameter reduction:
•True diameter-residual diameter=plaque diameter
•Plaque diameter / true diameter *100= % diameter stenosis.
Area reduction:
•residual/true = % residual open
•100% - %residual = % of stenosis
Stenosis velocities and ratios
Normal : <125 cm/s , <2.0 ratio <50% : <125 cm/s , <2.0 50-69% : 125-230, 2.0-4.0 ratio > or = 70% : >230cm/s , > 4.0 ratio Near occlusion Total occlusion, no flow
CCA
Low resistant, higher resistant near prox.
Abnormal: no diastolic flow = ICA occlusion further up.
ECA
High resistant
Branches
Important collateral pathway when there’s disease.
Abnormal ECA: no threshold values
Innominate artery
Gives rise to RT CCA and RT subclavian
Feeds arm, and cerebral circulation
Abnormal: when there’s a stenosis in Innominate, you’ll see tardus parvus in RT CCA
Patients with poor cardiac output will show _____ PSV in carotid exam bilaterally
Low PSV
Bicephorous waveform. Double peaks. Seen in patients with
Severe Aortic regurgitation.
Sharp upstroke. 2 peaks separated by a diacrotic notch. 2nd peak equal or taller than first.
If see tardus parvus in bilateral ICA, would be indicative of ______
Aortic valve stenosis.
Tardus Parvus: Prolonged acceleration, blunted amplitude, rounded waveform.
ICA occlusion
If ICA is occluded,
ECA collateral can be mistake for ICA. Becomes low resistant. Internalization of ECA.
May see increase flow in contralateral ICA = compensatory flow
Externalized (High resistant flow patterns) of ipsilateral CCA
Not operative
Near occlusion of ICA
Endarterectomy done when stenosis.
For string lesions or diffuse narrowing of ICA it’s not possible due to no focal stenosis to be removed. May lígate ICA to decrease source of emboli
If CCA occluded
Branches of vertebral system supply ECA and
ECA will show retrograde flow to feed ICA
Carotid artery dissection
Blood enters artery wall, separating wall layer, creating a false lumen
Echogenic flap, blood in false lumen may thrombos
Causes: trauma MC, connective tissue disorder Marfan’s syndrome or Ehler’s-Danlos
In Carotid: MC cause is atherosclerosis. Can extend to ICA
(MC dissection occurs in ascending aortic arch. )
