Ischemic Stroke Flashcards

1
Q

Stroke is

A

Injury to the brain caused by interruption of bloodflow or by bleeding into or around. Produces teh abrupt onset of focal neurologic defects that frequently result in permanent disability or death.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Transient Ischemic attack

A

abrupt onset of focal neurological deficits that resolve in less than an hour.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What percentage of strokes are hemorrhagic and describe a hemorrhagic stroke

A

about 20%… Hemorrhagic strokes may be caused by bleeding into the parenchyma of the brain or around the surface of the brain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Bleeding into parenchyma of brain called

A

Intracerebral hemorrhage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Bleeding around the surface of the brain called

A

subarachnoid hemorrhage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Ischemic stroke may have what 4 potential underlying causes?

A

1) Atherosclerotic occlusion of an intra/extracerebral blood vessel
2) Embolus
3) Lacunar infarcts ( disease of the lumen of small arterioles
4) 30% are cryptogenic (unknown cause)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Stroke risk factors

A
  • Age: doubles each decade
  • Gender: male at one and a half times higher risk
  • Race: african americans
  • Family Hx
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Modifiable stroke risk factors

A
  • HTN
  • Diabetes
  • Hyperlipidemia
  • Smoking
  • Carotid Artery Stenosis
  • Atrial Fib
  • Obesity
  • Physical inactivity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

In the absence of blood supplying glucose to the brain, each 100gm of brain has sufficient energy stores to last how long?

A

two and a half minutes. The brain has very little energy storage. Thus, important to keep blood flowing to it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Hyperthermia and hyperglycemia accelerate and worse stroke brain injury

A

ok

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Under normal conditions, neurons metabolize glucose delivered by the blood almost exclusively through what type of metabolism

A

aerobic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Within minutes of the loss of blood supply, brain energy stores are depleted through the metabolism of glucose via glycolytic pathways with the accumulation of lactic acid.

A

Lactic acid is bad. High temps will accelerate glycolytic lactic acid production as will high blood glucose levels. Body temperature and blood glucose should be brought down asap.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Ischemic core

A

The central area downstream of an embolus most affected by loss of bloodflow, fewer collaterals providing circulation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Ischemic Prenumbra

A

Peripheral areas with less severe ischemia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Ischemic core suffers irreversible injury how fast?

A

Within 1 hour or less

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Ischemic prenumbra may survive for how long?

A

Hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Therapeutic window for stroke intervention is generally recognized as being

A

4-6 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

slide 15

A

KNOW IT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

CBF (Cerebral blood flow) in norma individuals?

A

around 55ml/100gm brain/ minute

20
Q

Neurologic signs and symptoms produced by stroke include

A
  • weakness or paralysis
  • loss of sensation
  • loss of vision in one eye
  • difficulty talking or understanding what is being said
  • difficulty with organization or perception
  • clumsiness
21
Q

Anterior circulation stroke involves occlusion of:

A

Internal Carotid Artery
ANterior Cerebral
Middle Cerebral

22
Q

Posterior Circulation stroke involves occlusion of:

A

Posterior Cerebral
Vertebral artery
Superior Cerebellar Artery
Anterior Inferior Cerebellar Artery

23
Q

Besides vessel location, what is the other way to classify ischemic stroke?

A

Vessel sze

24
Q

Middle Cerebral Artery

A

KNOW

25
Q

Small penetrating branches of the MCA called

A

Lenticulostriate arteries

26
Q

Know slide 21…anterior and middle cerebral and what parts of the brain they provide vasculature to

A

ok

27
Q

What are the three clinical brainstem stroke syndromes?

A
  • Lateral Medullary Syndrome
  • Pontine syndrome
  • Midbrain syndrome
28
Q

Medullary Stroke Syndrome features

A
  • Loss of pain and temperature from the ipsilateral side of the face due to lesion of the trigeminal nucleus and tract
  • Dysarthria and Dysphagia due to lesion of nucleus ambigus
  • Loss of pain and temperature on the contralateral side of the body due to lesion of spinothalamic tract
  • Gait ataxia on the ipsilateral side of the body due to lesion of the spinocerebellar tract
29
Q

Medullary stroke syndrome due to

A

occlusion of the PICA or vertebral artery?

30
Q

Pontine Stroke Syndrome

A
  • Gaze disorders due to a lesion of the medial longitudinal fasiculous
  • Loss of epicritic sensation and proprioception on the contralateral side of the body due to a lesion of the medial lemniscus.
  • Cerebellar lesions on both sides of the body due to lesion of the pontine nuclei and transverse cerebellar fibers
  • Contralateral hemiparesis due to lesion of corticospinal tract
31
Q

Midbrain stroke syndrome

A

see slide 27 for symptoms

32
Q

Anterior Circulation Stroke

A
  • Ipsilateral blindness or contralateral inferior quadrantanopsia ( blindness in 1 quarter of the visual field)
  • Contralateral gaze paresis
  • contralateral mono/hemiparesis and/or mono/hemisensory deficit
  • Aphasia in the dominant hemisphere or neglect in the non-dominant
33
Q

Posterior Circulation Stroke

A
  • unlateral, bilateral, or crossed weakness or sensory deficits
  • contralateral homonymous hemianopsi or superior quadrantanopsia
  • vertigo, nausea/vomitting, gait ataxia, diplopia, dysphagia, horner’s syndrome
  • Altered consciousness and amnesia
34
Q

The middle cerebral artery supplies blood to what functional brain areas

A
  • Obviously the pre and post central gyri- so motor and sensory to just about every part of the body
  • The frontal eye fields (field of vision)
  • Broca’s area (speech)
  • Wernicke’s area (comprehension)
  • Visual Radiations (visual)
35
Q

Anterior Cerebral Artery supplies blood to what functional parts of the brain

A

Supplies to the motor and sensory portions (pre and post central) for the hip, leg, and foot

36
Q

Posterior Cerebral

A

Visual radiations of occipital lobe

37
Q

Wallenberg syndrome

A

occlusion of vertebral and PICA

  • Loss of pain and temperature from ipsilateral side of face due to lesion of the spinal trigeminal nucleus and tract
  • Dysarthria and Dysphagia: lesion to nucelus ambiguus
  • Loss of pain and temperature on teh contralateral side of the body- spinothalamic tract
  • Gait ataxia on the ipsilateral side of the body- spinocerebellar tract
38
Q

Important to distinguish cerebral infarction from selective ischemic necrosis.

A

Cerebral infarction- Focal brain ischemia leading to focal necrosis of all cellular elements

Selective Ischemic Necrosis- Only brain neurons injured. Most frequently seen in pts suffering from cardiac arrest and cardiac resuscitation. Affects only specific populations of highly vulnerable neurons…Like the CA1 pyramidal neurons of the hippocampus or the cerebellar purkinjee cells

39
Q

Common sites for atherothrombotic plaque buildup

A
  • Origins or carotid and vertebral arteries
  • Bifurcation of common carotid artery
  • Internal carotid arteries at the carotid siphon
  • M1 segment of the middle cerebral
  • Basilar
40
Q

Most common cause of cardiogenic emboli affecting the brain is

A

atrial fibrillation

Other causes include: mitral stenosis, bacterial endocarditis, and prosthetic heart valves

41
Q

CNS vaculitis presentation

A

multiple cerebral blood vessels involved so typicaly pts present with multiple focal defects

42
Q

Giant cell temporal arteritis

A

causes unilateral headaches over the temoral artery. Untreated can lead to strokes and blindness. Respondes well to steroids so catch it early

43
Q

Polycythemia and multiple myeloma are examples of

A

hyperviscosity syndromes (blood becomes thick)

44
Q

Also be on the look out for hypercoagulable conditions such as

A

antiphospholipid syndrome, protein C and S deficiency, cancer, pregnancy, thrombocytosis

45
Q

Hemoglobinopathies

A

sickle cell