Cerebrovascular disease & stroke Flashcards

Question

Modifiable/Treatable risk factors of stroke:

Answer 1

○ Smoking ■ Even second-hand ○ Hypertension ○ Diabetes Mellitus ○ Hyperlipidemia ○ Carotid Artery Stenosis ○ History of TIAs (secondary prevention) ○ Physical Inactivity and Obesity ○ Poor diet high in saturated fats and carbs ○ Receiving hormone replacement therapy (HRT) or estrogen birth control pills

Answer 2

○ Age ○ Biological sex ■ Slightly more common in males than females ○ Heredity and Race ■ Family history of CVA increases your risk ■ Individuals of African descent have a higher risk than other racial groups (see readings) ○ Prior Stroke or Heart Attack

Answer 3

● Atherosclerotic plaques frequently develop at the bifurcation of the common carotid in patients with risk factors. ● As the plaque develops and grows, stenosis develops. ● These plaques can become irritated and inflamed, which can result in ulceration and rupture of the plaque itself

Answer 4

a provider hears bruits over the carotids or incidentally on unrelated imaging, such as a thyroid ultrasound

Answer 5

■ For asymptomatic patients with less than about 70% stenosis ■ Lifestyle modifications for all ■ Aspirin 325 mg QD or Clopidogrel (Plavix)

Answer 6

■ For symptomatic patients or for asymptomatic patients with more than about 70% stenosis ■ Carotid Endarterectomy (CEA) is preferred ■ Don’t D/C Aspirin 325 mg QD for surgery

Answer 7

● Saccular aneurysms, often referred to as “Berry Aneurysms,” are small outpouchings coming off of larger arteries in the brain ● They can result from congenital defects, hypertension, atherosclerosis, trauma, etc. ● Can occur at any age, but incidence steadily increases after 25 years of age and is most prevalent in the 50’s and 60’s.

Answer 8

○ They tend to occur at arterial bifurcations at the Circle of Willis or in the Sylvian Fissure. ○ A natural weakness exists at these bifurcations. Cerebral Aneurysm “A Comprehensive Review for the Certification and Recertification Examinations for Physician Assistants,” O’Connell and Zarbock. ○ The adventitia of the arterial wall pushes through the elastic membrane of the artery, results in the berry aneurysm. ○ Berry Aneurysms may be associated with Polycystic Kidney Disease and Coarctation of the Aorta

Answer 9

○ May remain asymptomatic throughout life. ○ May grow and push on cranial nerves, causing cranial nerve palsies (especially CN VI). Cerebral Aneurysm “A Comprehensive Review for the Certification and Recertification Examinations for Physician Assistants,” O’Connell and Zarbock. ○ If and when they rupture, the patient experiences a severe and sudden headache ○ May experience rapid deterioration with altered mental status and coma ○ Patients commonly present with extremely high BP due to high ICP (which often occurs due to Obstructive Hydrocephalus). ○ The Subarachnoid Hemorrhage that occurs with the rupture can cause fever, stupor, coma, nuchal rigidity and other signs of meningismus

Answer 10

Cerebral Aneurysm

Answer 11

○ Ruptured Berry aneurysms account for 75% of non-traumatic cases of SAH seen on CT scans (Aneurysmal SAH) ○ Order CT head without contrast STAT as soon as you suspect SAH! ○ LP should be done to confirm negative CT ○ In a patient in whom you suspect an unruptured aneurysm, or if a CT or MRI suggests possible aneurysm… ■ MRA ■ CTA ■ or Cerebral Angio

Answer 12

○ Rupture of a Berry aneurysm carries a mortality rate of 40-50%. ○ Many patients die within minutes of the rupture, while others die days later as a result of cerebrovascular spasm or decreased cerebral perfusion ○ Surgical care may involve Endovascular Coiling (preferred) or Open Craniotomy for Clipping (old school but good). ○ Unruptured aneurysms are often watched with serial imaging, and if they get to more than 8 mm, coiling or clipping is often performed to prevent rupture

Answer 13

● Almost all AVMs are congenital and are often found in multiple places, not just one. ● Dural-based AVMs are an acquired condition that may be triggered by injury ● AVMs can occur anywhere in the body, but the ones in the brain present substantial risk when they decide to bleed

Answer 14

○ AVMs result from a localized maldevelopment of part of the primitive vascular plexus and vary in size from tiny to massive. Arteriovenous Malformations (AVM) “A Comprehensive Review for the Certification and Recertification Examinations for Physician Assistants,” O’Connell and Zarbock. ○ They consist of abnormal arteriovenous communications without intervening capillaries ○ AVMs have a tendency to rupture

Answer 15

■ Hemorrhage (less intense than aneurysm) in 30-60% ■ Recurrent seizures in 20-40% ■ Abnormal headache in 5-25% ■ Miscellaneous complaints (including focal deficits) in 10-15% of cases ○ Hemorrhages are sometimes both intraparenchymal as well as into the subarachnoid space and mortality rate is about 10%. ○ Up to 70% of AVMs bleed at some point, usually before 40 YOA. ○ Small AVMs are more likely to bleed than larger ones

Answer 16

○ If a hemorrhage is suspected, CT head STAT. ○ In patients without hemorrhage (but maybe with seizure, etc.), CT or MRI usually reveal the lesion. ○ To confirm the presence of an AVM, and to delineate the size and borders, order a Cerebral Angiogram

Answer 17

○ As long as the AVM is easily accessible and the patient has a good life expectancy, surgical treatment to prevent further hemorrhage is justified. Arteriovenous Malformations (AVM) “A Comprehensive Review for the Certification and Recertification Examinations for Physician Assistants,” O’Connell and Zarbock. ○ Removal might involve… ■ Open microsurgical excision ■ Stereotactic Radiosurgery (radiation) ■ Endovascular Embolization