Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

OPIC (Y4) > 2- Stroke: Ischaemic vs haemorrhagic stroke and brain imaging > Flashcards

2- Stroke: Ischaemic vs haemorrhagic stroke and brain imaging Flashcards

1
Q

ischaemic vs haemorrhagic stroke

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

ischaemia vs infarction

A

schemia means that blood flow to a tissue has decreased, which results in hypoxia, or insufficient oxygen in that tissue, whereas infarction goes one step further and means that blood flow has been completely cut off, resulting in necrosis, or cellular death.

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

stages of an infarct

A
  • hyperacute (6hours)
  • acute (>7 days)
  • subacute (up to 4 months)
  • chronic (after 4 months)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

management of hyperacute infarct (<6hours)

A
  • thrombolysis with alteplase
    • <4.5h
  • thrombectomy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

imaging of hyper-acute infarct

A

CT scan must occur before thrombolyis is given

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

why CT scanning

A
  • Available 24/7
  • Fast
  • Not limited by contraindications, intolerances and the need for life support/monitoring equipment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

CT techniques used

A
  • Unenhanced brain scan (CT)
  • CT Angiogram (CTA)
  • CT Perfusion scan (CTP)
  • CT Venogram (CTV) for venous thrombosis
  • Contrast enhanced brain scan (CECT) for blood brain barrier disruption
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

why the unenhanced CT

A

As soon as possible after stroke.

  • Primary Role
    • CT is highly sensitive for the detection of acute haemorrhage
    • CT is sensitive to the detection of stroke mimics e.g. tumour, arterial venous malformation (AVM) that could be the cause of the neurological defect.
    • may show target- thrombosed vessel
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how will a cerebral infarct present on an unenhanced CT

A
  • Hypoattenuating (whiter or brighter)
  • Cortical-sub cortical
  • Within a vascular territory
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Drawings (top) illustrate the territories (blue) of the ACA, middle cerebral artery (MCA) , and posterior cerebral artery

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

early signs of infarction on unehanced CT

A

image shows occlusion of MCA

  • Hypo-attenuation and sulcal effacement in the territory of affected artery
  • obscuration and loss of gray matter- white matter differentiation of the left basal ganglia and sulcal effacement in the territory of the affected artery
  • hyperattenuating affected artery
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

role of MRI

A

detection and diagnosis fo acute infarctiion

  • positive from 2 hours to 3 weeks
  • Useful
    • Previous CVD makes CT difficult
    • Difficult location for CT - posterior fossa
    • Equivocal case - query tumour?
    • Sensitivity - TIA clinic
    • MRA and MRV
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

acute R MCA infarct on MRI

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

when is alteplase licenced for

A

in the first 4.5 hours after event

  • may limit use of CT to eliminate haemorrhage and stroke mimics
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

perfusion CT

A
  • uses standard iodinated contrast
  • repeated images of the same (few) levels are obtained during the first pass of the contrast through the brain (40 seconds)
  • As contrast passes through the brain it causes a transient hyperattenuation directly proportional to the amount of contrast in the vessels of that region
  • The software can map from the serial images a time attenuation curve for the arterial input, the venous output and for each tiny voxel of brain tissue. From this we get both:
    • cerebral blood flow (CBF)
    • cerebral blood volume (CBV)
  • Perfusion CT maps of CBF and CBV can then be calculated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

when you overlay the CBV and CBF perfusion CT scan you can

A

identify potentially salvageable brain tissue- distinguishing ishcameia from infarction

  • When you overlay the two you can identify the infarct core (red).
    • The reduction in the CBV indicates irreversible infarction
  • And the ischaemic penumbra (green)
    • CBV is maintained in the presence of reduced CBF
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

why are perfusion CT scans helpful

A
  • We use the CBF and CBV maps to distinguish ischaemia from infarction
  • Thrombolysis can only benefit the ischaemic penumbra
    • No penumbra = no benefit
  • Thrombolysis in patients with a large core infarct just increases the risk of secondary haemorrhage
18
Q

brainstem infarct

A

this CT shows large pontine infarct and hyperattenuating basilar artery

Brainstem infarcts

  • Slower to appear
  • Slower to evolve
  • Likely longer therapeutic window
19
Q

Spontaneous Intracranial Haemorrhage (ICH)

A

15% strokes

Clinical clues

  • Possible underlying cause
  • Reduced level of consciousness at admission
  • History of headache Seizures
20
Q

primary haemorrhage

A

small vessel

  • htn
  • cerebral amyloid angiopathy
21
Q

secondary haemorrhage

A
  • haemorrhagic transformation infarct
    • venous sinus thrombosis and venous infarction
  • tumour
  • vascular
    • aneurysm
    • avm
    • vasculitis
  • coagulopathy
  • cocaine,alcohol
22
Q

intracranial haemorrhage can be

A
23
Q

diagnosis of intracranial haemorhhgage

A

CT inittially and then MR

24
Q

CT in the diagnosis of intracranial haemorrhage

A
  • acute bleed and immediate complications of acute bleed
  • underlying cause- CTA, CTV
25
Q

MRI and intracranial haemorrhage

A
26
Q

management of intracranial haemorrhage

A
  • Medical
    • supportive
    • blood pressure management
    • mass effect
    • sezuire prevention
    • secondary prevention
  • Surgical
    • neurosurgery for clot reduction, decompression craniotomy
    • neurosurgery for intraventricular shunting
      • mandated in hydrocephalus
27
Q

haemorrhage on CT

A

increased attenuation (opaque)

describe in terms of:

  • location
  • size
  • age
  • presence or absence of mass effect
  • complications e.g. hydrocephalus
28
Q

hypertensive bleeds tend to be found

A

deep - basal ganglia or cerebellum- unless hydrocephalus do not benefit from surgical intervention

29
Q

peripheral haemorrhage causes

A

underlying tumour, vascular abnormalities, vascular degeneration e.g. from cerebral amyloid angiopathy

30
Q

haemorrhagic transformation

A

is a common complication in patients with acute ischemic stroke. It occurs when peripheral blood extravasates across a disrupted blood brain barrier (BBB) into the brain following ischemic stroke. Preventing HT is important as it worsens stroke outcome and increases mortality.

31
Q

cerebral amyloid angiopathy (CAA)

A
32
Q

intratumoral ahmeorrhage

A
33
Q

arteriovenous malformation

A
34
Q

anticoagulant haemorrhage

A
35
Q

complications of intracranial haemorrhage

A

Mass effect

36
Q

membranes which surround the brain

A
37
Q

extradural haematoma

A

also known as epidural

  • presentation
    • trauma
    • LOC, consciousness, LOC (lucid intervals)
  • Pathophysiology
    • middle meningeal artery
  • CT scan
    • biconvex bleed (lemon)
38
Q

subdural

A

presentation

  • presentation
    • elderly
    • trauma
  • pathophysiology
    • torn bridging veins
    • brain atrophy
  • concave towards brain (banana)
39
Q

subarachnoid heamorrhage

A
  • presentation
    • older
    • HTN. smoker
    • thunderclap headache
    • nausea and vomiting
    • LOC
  • pathophysiology
    • arteriovenous malformations
    • berry aneurysm
40
Q

Saccular aneurysms (berry aneurysms)

A
  • Aneurysms develop due to pressures on the arterial wall (vessels in subarachnoid space)
  • Usually at bifurcation points
  • Large cerebral arteries in anterior circle of Willis most affected
  • Intracranial arteries lack external elastic lamina and have thin adventitia
  • Small aneurysms(<5mm) unlikely to rupture
  • Risk factors for developing aneurysms (not conclusive)
    • Same as cardiovascular- hypertension, smoking etc
    • Alcohol++
41
Q

investigations for suspected subarachnoid haemorrhage

A

1st line- CT scan

  • Will detect 93% if done within 24 hours of bleed
  • Small amounts of blood can be hard to see
    • If convincing history but negative CT scan do a lumbar puncture (LP)
      • Should wait at least 6 hours (12+ is preferable)- need time for lysis of red blood cells to take place (release of bilirubin)
      • This gives the CSF a yellow tinge after centrifuging (this can differentiate this from traumatic tap) called Xanthochromia
      • CSF will have high protein, WCC not raised, glucose normal

Once diagnosis confirmed

  • Angiography is performed to confirm location of aneurysm
42
Q

management of subarachnoid haemeorrhage

A
  • Assessment of whether they need airway support
  • Monitoring of cardiovascular parameters
  • Calcium channel blockers- Nimodipine (to prevent vasospasm and secondary ischaemia)
  • Operate on patients who have good neurological status within 72 hours -to prevent re-bleeding
    • Clipping (surgeons)à Clamping neck of aneurysm (with spring clip)
    • Coiling (neuro-radiologists) à Insertion of wire into aneurysm sac which causes thrombosis of blood within aneurysm

OPIC (Y4) (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions