3. Vascular Disease & Stroke

Question 1

SUDDEN onset of a focal neurological impairment due to ischemia or hemorrhage; NOT reversible; more common in older men; risk factors are DM, HTN, Smoking, Hyperlipidemia, Obesity and Sleep Apnea

Answer 1

Stroke

Question 2

Two types of Strokes

Answer 2

Ischemic
Hemorrhagic *

• less common but more fatal

Question 3

(Ischemic/Hemorrhagic) strokes are more common

Answer 3

Ischemic (~80%)

Question 4

(Ischemic/Hemorrhagic) strokes are commonly caused by atherosclerosis with thrombosis in LARGE vessels and/or embolic occlusion of DISTAL vessels; can also occur due to venous thrombosis like in superior sagittal sinus (due to infection or hyper-coagulation states in pregnancy)

Answer 4

Ischemic

Question 5

Emboli causing an ischemic stroke often originate from

Answer 5

EXTRA-cranial thrombi (atherosclerosis of Carotid artery bifurcation or from the heart)

Question 6

What is the spectrum of consequences of brain ischemia (best to worst)

Answer 6

1. No effect (thanks to anastomoses!)
2. TIA (brief, focal neurologic deficits but reversible)
3. “Incomplete” infarct (neuronal necrosis)
4. “Complete” infarct (BOTH neuronal AND glial necrosis)

*neurons are more vulnerable that glial cells to ischemia

Question 7

There typically no gross changes in the brain with CT until ________ HOURS after the infarct

Answer 7

6-8

Question 8

CT findings of brain infarct (remember that it takes 6-8 hours for anything to be grossly visible)

Answer 8

Early (1-2 days): congestion, discoloration of grey matter

Late: cavitation (phagocytosis of dead tissue)

Question 9

Histologic findings of a brain infarct

Answer 9

1. Hours: Red (“dead”) neurons
2. 24 hours: neutrophilic infiltrate
3. 48 hours: Macrophage infiltrate –> discoloration of grey matter
4. Weeks: Macrophage clear debris –> cavitation

Question 10

(Focal/Global) ischemia is due to the occlusion of a blood vessel; infarct in local area; commonly due to…

1. atherothrombosis (1 large vessel or many small vessels)
2. intra-arterial (artery to artery) emboli, and
3. cardiogenic emboli.

Answer 10

Focal (or “territorial” or “local”)

• more common than global

Question 11

(Focal/Global) ischemia is due to cardiac arrest, systemic hypotension or increased ICP cutting off cerebral perfusion; causes widespread necrosis that can be accentuated or limited to watershed areas

Answer 11

Global (or “generalized”)

*note watershed areas (시냇물 shape)

Question 12

The maximal amount of swelling after an infarct is usually within

Answer 12

one week

*can cause a mass lesion

Question 13

Peripheral rim of “lesser” ischemia surrounding a central core of maximal ischemia

Answer 13

Penumbra

Question 14

Consequences of Brain Infarcts

Answer 14

Focal neurologic deficites
Cognitive impairment (Vascular dementia)

Question 15

Common causes of Brain Hemorrhage

Answer 15

Hypertensive small-vessel disease
Ruptured Berry Aneurysm
Ruptured arteriovenous malformation
Cerebral amyloid angiopathy
Drugs/Neoplasm/Trauma

Question 16

MOST common cause of Intracerebral Hemorrhage

Answer 16

Hypertension

Question 17

Acute hypertensive hemorrhage typically occurs in what two vessels?

Answer 17

1. Lenticulostriate vessels (branches of MCA supplying deep cerebral nuclei like putamen)
2. Pontine arteries (branches of Basilar artery)
   * note that they are “SMALL” vessels

Question 18

Most common cause of a Subarachnoid Hemorrhage (hemorrhage that moves into CSF space b/w arachnoid and pia maters); patients often say worst HA of my life; CSF xanthochromic (bilirubin in CSF)

Answer 18

Ruptured Berry Aneurysms

Question 19

Abnormal dilation of an artery (due to weakening of vessel wall) that arise at the base of the brain where the major blood vessels meet (“Circle of Willis”); most occurs in Anterior circulation; MOST don’t rupture but still a concern; NEVER occurs in children

Answer 19

Berry Aneurysm

Question 20

Berry aneurysms are more likely in the (anterior/posterior) circulation of the Circle of Willis

Answer 20

Anterior

Question 21

Mean age of Berry Aneurysm rupture (remember vast majority don’t ever rupture)

Answer 21

50

Question 22

HTN, smoking, cocaine, heavy alcohol consumption, and heritable CT disorders (Ehlers-Danlos, ADPKD, etc.) are the major risk factors of

Answer 22

Berry aneurysm RUPTURE

• rarely ruptures though

Question 23

Consequences of Aneurysm rupture

Answer 23

Inc. ICP (can cause mass effect)
Hydrocephalus
Re-bleeding of aneurysm
Secondary vasospasm of cerebral arteries

Question 24

Tangle of abnormal arteries and veins bypassing capillary bed; often WEDGE-shaped area involving brain and leptomeninges (arachnoid+pia); may rupture and hemorrhage

Answer 24

Arteriovenous malformations (AVM)

Question 25

Brain tumor composed of small, tightly packed thin-walled blood vessels; can rupture and may cause seizures

Answer 25

Cavernous Angioma (aka. Cavernoma)

Question 26

Examples of brain vasculitis

Answer 26

``` Giant Cell (aka. Temporal) arteritis* Primary angiitis of the CNS Polyarteritis Nodosa ``` *most common

Question 27

Most common primary vasculitis involving the CNS; peak age of about 80; twice as often in females; temporal artery usually involved; highly associated with polymyalgia rheumatica; histologic findings of granulomatous inflammation, multi-nucleated giant cells, and fragmented internal elastic lamina

Answer 27

Giant Cell Arteritis * aka. Temporal Arteritis

Question 28

TRANSIENT episode of neurologic dysfunction resulting from focal brain, spinal cord or retinal ischemia; usually only lasts <1 hour; NOT associated with permanent cerebral infarction (if yes, then it's a stroke)

Answer 28

Transient Ischemic Attack

Question 29

(Intracerebral/Subarachnoid) hemorrhages are more common

Answer 29

Intracerebral (70%)

Question 30

A-fib, prosthetic valves, acute MI, dilated cardiomyopathy, endocarditis, and ventricular aneurysm are some cardiac sources of ______ causing ischemic stroke. ____________ is less likely to cause an emboli in elderly but is a common cause of "young stroke".

Answer 30

Emboli Patent Foramen Ovale

Question 31

Basal ganglia (striatum + GP) and internal capsule are supplied by

Answer 31

lenticulostriate arteries (from MCA)

Question 32

Midbrain and thalamus are supplied by

Answer 32

perforators from PCA

Question 33

Caudate is supplied by

Answer 33

perforators from ACA ("recurrent artery of Heubner")

Question 34

Internal capsule is supplied by

Answer 34

1. lenticulostriate arteries (from MCA) | 2. Anterior choroidal artery (from Internal Carotid Artery)

Question 35

Effects of stroke caused by "carotid" ischemia (anterior circulation) * think about the anterior portion of brain supplied by internal carotid arteries and its branches

Answer 35

1. TIA 2. Motor (CONTRALATERAL weakness) 3. Language disturbance (if dominant hemisphere)

Question 36

Effects of MCA Stroke * think about the brain area supplied by MCA (lateral parietal lobe, lateral frontal lobe, and temporal lobe)

Answer 36

1. Contralateral paralysis and sensory loss of face and upper limb (lateral homunculus) 2. Broca's Aphasia (if lesion in dominant hemisphere) 3. Wernicke's Aphasia

Question 37

Effects of ACA Stroke * think about the brain area supplied by ACA (medial parietal lobe, medial frontal lobe, and caudate)

Answer 37

1. Contralateral paralysis and sensory loss of lower limb (medial homunculus) 2. Urinary incontinence (loss of bladder control)

Question 38

Effects of PCA Stroke * think about the brain area supplied by PCA (occipital lobe, thalamus)

Answer 38

1. Contralateral hemianopia with macular sparing 2. Hemisensory loss 3. Anton syndrome (denial of blindness)

Question 39

Effects of stroke caused by "vertebrobasilar" ischemia (posterior circulation) * think about the posterior portion of brain supplied by vertebrobasilar arteries

Answer 39

1. Diplopia/Binocular blurring or loss of vision 2. Unilateral or bilateral weakness in limbs 3. Vertigo/lack of coordination (look drunk)

Question 40

Small infarcts deep in the hemispheres, brainstem or cerebellum; often associated with HTN/DM

Answer 40

Lacunar Infarcts * lacunar = small vessels

Question 41

Lacunar infarct in what area of brain causes PURE MOTOR syndrome? * contralateral F, A, L motor loss

Answer 41

Posterior limb of internal capsule (supplied by "anterior choroidal artery", a branch of ICA)

Question 42

Lacunar infarct in what area of brain causes PURE SENSORY syndrome? * contralateral Face, Arm, Leg sensory loss

Answer 42

Thalamus (supplied by perforating arteries of PCA)

Question 43

Often described as "worst HA in my life"; LP shows CSF xanthochromic (bilirubin is found in CSF)

Answer 43

Aneurysm rupture —> subarachnoid hemorrhage

Question 44

Non-contrast CT scan is sensitive for

Answer 44

Hemorrhage * blood will appear WHITE

Question 45

Why do we use NON contrast for CT scans of the brain

Answer 45

With contrast, lit up areas could be either bone, blood or contrast *non-contrast means it can only be blood or bone

Question 46

MRI scan is sensitive for

Answer 46

Early detection of ISCHEMIC stroke *CT can take days to show effects, while MRI can show within hours

Question 47

When should you use Thrombolysis (rt-PA) for strokes?

Answer 47

ISCHEMIC ONLY

Question 48

``` >5 hours since onset Head trauma Hx of intracranial hemorrhage Low platelets Recent surgery ``` are contraindications for * they all increase risk of bleeding

Answer 48

thrombolytics for strokes

Question 49

(Carotid Endarterectomy/stenting) is preferred in asymptomatic with at >60% stenosis or symptomatic with 70-99%

Answer 49

Carotid Endarterectomy

Question 50

(Carotid Endarterectomy/stenting) is preferred in symptomatic or asymptomatic with high grade ICA stenosis

Answer 50

Stenting

Question 51

Drug for the treatment of acute stroke/TIA

Answer 51

rt-PA (Tissue Plasminogen Activator)

Question 52

Drugs for secondary prevention of Stroke/TIA

Answer 52

Antiplatelets (Aspirin + Clopidogrel for 21-90 days) Anticoagulants (Warfarin, Dabigatran, Apixaban, etc.)

Question 53

Treatment plan for Hemorrhagic Stroke

Answer 53

1. Identify/fix cause of bleed 2. * BP management *because usually due to HTN