Stroke syndromes

Question 1

What is an embolic stroke?

Answer 1

Masses formed elsewhere in the circulatory system travel through the bloodstream to block brain vessels of smaller diameter than the embolus

Question 2

What is a thrombotic stroke?

Answer 2

Buildup of atherosclerotic plaques within vessel walls, resulting in gradual vessel occlusion

Question 3

What is tissue plasminogen activator (tPA)?

Answer 3

Breaks up closse

Effectiveness significantly diminished >3 hours after infarct

Question 4

What is an intracerebral hemorrhage?

Answer 4

Internal bleeding in the brain

can cause stroke

Question 5

What are the most immediate pathogenic events in focal cerebral ischemia?

Answer 5

Anoxic depolarization

Excitotoxicity

Question 6

What is a focal stroke characterized by?

Answer 6

Gradient of metabolic stress radiating from the core

Depolarizations become shorter-lasting as you move away from the core

Question 7

How is the ischemic core defined?

Answer 7

Spread of anoxic depolarization

Peri-infarct depolarizations recover and recur in penumbra area surrounding ischemic core

Question 8

What options must be considered when imaging a stroke?

Answer 8

Non-contrast CT - must be performed to rule out hemorrhage prior to tPA admin.

CT - widely available, rapid results

Diffusion-weighted MRI scans - much more accurate, but availability/cost must be considered

Question 9

What is the penumbra?

Answer 9

Area immediately surrounding the dead core that is potentially salvageable with intervention

Question 10

What is a lacunar infarct?

Answer 10

Small infacted area (end artery occlusion)

Question 11

What is a watershed infarct?

Answer 11

Occlusion between 2 major artery distributions

E.g. MCA/PCA border

Question 12

What is a transient ischemic attack?

Answer 12

Acute episode typically resolved within 30 minutes

Critically important to recognize diagnose, and treat

Highly predictive of a major stroke

Question 13

What is amaurosis fugax?

Answer 13

Transient, unilateral loss of vision resulting from occlusion of the central retinal artery

Question 14

What symptoms result from cortical strokes (i.e. large vessel strokes)?

Answer 14

Contralateral spastic limb and lower face paralysis with babinski

Contralateral fine touch and proioception loss

Ipsilateral vision loss

Aphasia if in dominant hemisphere

Question 15

Describe middle cerebral artery strokes.

Answer 15

Three regions: Superior, inferior, deep

Primarily upper signs

Dominant hemisphere - global aphasia

Tongue deviation away from the side of the lesion

Question 16

What is a stem infarct?

Answer 16

Proximal MCA occlusion covering all three regions; often present with gaze preference toward the side of the lesion

Question 17

Describe anterior cerebral artery strokes

Answer 17

Primarily lower signs that present as UMN weakness

Medial frontal lobe effects - abulia, akinetic mutism, urinary incontinence

Question 18

Describe posterior cerebral artery strokes

Answer 18

Contralateral homonymous hemianopsia

Memor deficits

Alexia without agraphia

Question 19

Describe subcortical strokes

Answer 19

Small vessel strokes

Smaller, more limited territories supplying deep white matter

Present similarly to cortical strokes, except for a lack of cortical signs

Lenticulostriate arteries supply genu and posterior limb of the IC

Question 20

Describe thalamic strokes

Answer 20

PCA, P. Comm., Ant. Choroidal

Wide range of symptoms

Contralateral homonymous hemianopsia - involving LGN

Thalamic syndrome - Extreme contralateral pain

Question 21

What differentiates brainstem from cortical strokes?

Answer 21

Brainstem presents with ipsilateral numbness instead of contralateral

Question 22

What is Weber’s syndrome?

Answer 22

Stroke involving penetrating branches of the PCA

Contralateral paresis/paralysis below neck

Ipsilateral oculomotor ophthalmoplegia

Question 23

What is Claude’s syndrome?

Answer 23

PCA/basilar artery stroke

Contralateral upper limb tremor, ipsilateral oculomotor ophthalmoplegia

Question 24

What is Benedikt’s syndrome?

Answer 24

Penetrating branches of the basilar artery

Combination of Weber’s and Claude’s

Question 25

Describe a rostral pontine stroke

Answer 25

Contralateral spastic paresis with babinski in lower face and body

Question 26

Describe a caudal pontine stroke

Answer 26

Ipsilateral whole facial paresis

Medial strabismus

Contralateral UMN signs (corticalspinal tract axons)

Question 27

What is Locked-in syndrome?

Answer 27

Bilateral damage to basal pons due to massive basilar artery stroke

Patient suffers complete paralysis but is not comatose because consciousness is spared

Question 28

Describe a lateral medullary stroke

Answer 28

Wallenberg’s syndrome - laryngeal muscles

Contra loss of pain/temp body below neck

Ipsi loss of pain/temp face

Vestibular nuclei signs (nausea, vertigo)

Question 29

Describe a medial medullary stroke

Answer 29

Involves medial lemniscus, pyramid, and exiting CN XII fibers

Contra loss of fine touch, vibration, conscious proprioception

Tongue deviation towards the side of the lesion

Question 30

Describe Cerebellar strokes

Answer 30

Inability to walk; ataxia

Dizziness, headache, nausea, vomiting