Cerebrovascular disease

Question 1

define a transient Ischemic attack

Answer 1

sudden, focal neurological deficits which completely resolve within 24 hours

are a serious warning of stroke risk

Question 2

what is the most common cause of a stroke

Answer 2

ischemic infarction

Question 3

what are stroke risk factors

Answer 3

atherosclerosis risk factors - hypertension, heart disease, diabetes, smoking, hyperlipidemia and a family history of vascular heart disease

Question 4

where do atherosclerotic changes predominate

Answer 4

at the bifurcation points of large major cervical and intracranial arteries (more turbulent flow)

Question 5

what are the 2 mechanisms of ischemic infarction

Answer 5

1. local arterial thrombosis of an atheroma

2. embolic arterial occlusions from a proximal source

Question 6

what is the most important factor in determining whether a patient is able to create collateral blood flow

Answer 6

a complete circle of willis

Question 7

describe how a patient may have an asymptomatic occlusion of a cervical internal carotid artery

Answer 7

if a thrombosis is formed gradually, other arteries may detour blood flow to the potentially ischemic areas of the brain

Question 8

how does a large artery infarction appear pathologically

Answer 8

the cerebral cortex will appear soft and swollen with less distinction of the gray-white matter junction and spotty hyperemia

Question 9

microscopically 12-36 hours after a stroke how does the brain appear

Answer 9

ischemic neurons shrink and appear eosinophilic (“pink neurons”)

Question 10

what is seen microscopically days after a stroke

Answer 10

macrophages scavenge necrotic debris and cyst formation occurs with astrocytes at the periphery of the infarction

Question 11

what causes lacunar infarcts

Answer 11

thrombosis (not emboli)

Question 12

what is a lacunar infarct

Answer 12

a small lesion of a perforator or lenticulostriate artery which are small branches from larger arteries that supply the deep structures of the brain

Question 13

why are lacunar infarcts significant

Answer 13

they typically occur in the basal ganglia, internal capsule, thalamus and corona radiata- areas with complex and important functions so even a couple mm lesion can cause serious neurological deficits

Question 14

what is amaurosis fugax

Answer 14

monocular blindness - one type of carotid territory TIA . Pt describes a lowered dark shade in one eye which gradually lightens up

Question 15

what types of symptoms do vertebrobasilar territory TIAs cause

Answer 15

ataxia, homonymous hemianopsia, or hemiparesis associated with crossed brainstem syndromes

Question 16

vertebrobasilar territory TIAs cause ischemia of what areas

Answer 16

brain stem. cerebellum, visual (occipital) cortex

Question 17

carotid TIAs produce symptoms of

Answer 17

hemispheral ischemia leading to hemiparesis or aphasia

Question 18

where does a hemiparesis with greater weakness of the face and upper limb suggest the location is

Answer 18

the precentral middle cerebral artery territory

Question 19

where does a hemiparesis with great weakness of the lower limb suggest the location is

Answer 19

precentral anterior cerebral artery territory

Question 20

where does sensory deficits limited to the face and upper limb suggest the infarct is

Answer 20

postcentral MCA

Question 21

where does sensory deficits limited to the lower limb suggest an infarct is located

Answer 21

postcentral ACA

Question 22

what kind of stroke is suggested by pure motor hemiplegia, ataxic-hemiparesis and clumsy hand-dysarthria

Answer 22

a lacunar stroke of the internal capsule, corona radiata or basilar pons

Question 23

a pure sensory stroke is indicated of what type of stroke

Answer 23

a lacunar syndrome from a small vessel occlusion involving the thalamus

Question 24

what is an atheroma

Answer 24

(arterial plaques) form from subintimal lipid deposition, smooth muscle proliferation & fibrosis.

Question 25

how do atheromas lead to stroke

Answer 25

Bulging atheromas or plaques can narrow or occlude the arterial lumen (thrombosis), or ulcerate and travel downstream (embolize).

Question 26

what are possible cardiac sources of an embolis

Answer 26

MI A. fib valvular lesion R to L shunt (patent forman ovale)

Question 27

what are some hypercoaguable states that may contributed to a stroke

Answer 27

sickle cell anemia, polycythemia vera, vasoactive recreational drugs (cocaine)

Question 28

what other pathologies must be ruled out when a stroke is suspected

Answer 28

atypical presentation of tumor, hemorrhage, abscess, or encephalitis

Question 29

what is used to confirm the diagnosis of a stroke

Answer 29

MRI (CT is second best)

Question 30

should a source of embolism be looked for in a lacunar stroke

Answer 30

no - it is unlikely that an embolism would cause a lacunar stroke. they are typically thrombotic

Question 31

what is a carotid endarterectomy

Answer 31

the surgical removal of an atheromatous lesion

Question 32

when should a carotid endarterectomy be done

Answer 32

in patients with symptomatic lesions of 70-99% blockage at the origin of the internal carotid artery

Question 33

if carotid endarterectomy is not option what other treatments are available

Answer 33

stenting and angioplasty

Question 34

within what time frame should tPA be adminstered

Answer 34

within 3 hours of stroke onset

Question 35

what are the symptoms of a cerebral hemorrhage

Answer 35

severe headache, early impairment of consciousness (atypical for infarction)

Question 36

what is the cause of death in a severe hemorrhage

Answer 36

shifting or herniation of the brain

Question 37

what is the best imaging to identify a bleed

Answer 37

CT - blood is white

Question 38

what is the most common cause of cerebral hemorrhage

Answer 38

Hypertension weakened walls of small, penetrating arterioles rupture. Typical bleeding sites: basal ganglia and thalamus

Question 39

what are causes of cerebral hemorrhage

Answer 39

hypertension head trauma rupture of congenitally abnormal blood vessels bleeding within an ischemic infarction or tumor systemic bleeding gidsorders illicit drugs (via hypertension) cerebral amyloid angiopathy (elderly patients)

Question 40

what's the most common cause of a subarchnoid hemorrhage (SAH)

Answer 40

trauma

Question 41

what is a berry aneurysm

Answer 41

- thinned out pouchings at intracranial arterial bifurcations - may enlarge over time with increased risk of rupture

Question 42

what is the most common location for a Berry aneurysm

Answer 42

the anterior circle of willis

Question 43

what is berry aneurysm syndromes

Answer 43

- asymptomatic - warning leak - worst head of my life w/ meningeal signs - mass effect (CN III palsy) - massive, fatal SAH

Question 44

how would you evaluate symptomatic berry aneurysms

Answer 44

- CT brain scan - lumbar puncture (if CT is normal to verify SAH) - cerebral angiogram - emergent clipping or endovascular coiling of aneurysm