JC30 (Surgery) - Cerebrovascular events Flashcards by Max Kam

List 5 types of cranial haemorrhage typically caused by trauma or occur spontaneously

Traumatic/ spontaneous:

Lobar intracerebral haemorrhage
Subarachnoid haemorrhage

Traumatic:
- Extradural or subdural haemorrhage

Spontaneous:

Intraventricular haemorrhage
Deep intracerebral hemorrhage

How well did you know this?

Not at all

Perfectly

Outline major subtypes of ischemic and haemorrhagic stroke

Ischemic stroke:

Thrombotic
Embolic
Systemic hypoperfusion

Haemorrhagic stroke:

Intracerebral
Subarachnoid

How well did you know this?

Not at all

Perfectly

Compare onset between ischemic and hemorrhagic stroke subtypes

Ischemic:

Thrombosis: Stuttering progression with periods of improvement
Embolic: Sudden onset, deficit maximal at onset
Systemic hypoperfusion: Diffuse, gradual onset

Haemorrhagic:

Intracerebral haemorrhage: Gradual progression (mins or hours)
Subarachnoid haemorrhage: Sudden onset (seconds)

How well did you know this?

Not at all

Perfectly

Common sites of lacunar infarct

o Pons
o Thalamus
o Internal capsule/ Corona radiata
o Basal ganglia (caudate/ putamen/ globus pallidus/ subthalamic nuclei/ substantia nigra)

How well did you know this?

Not at all

Perfectly

Common sites of ischemic stroke due to systemic hypoperfusion

Boundary zone (border/ watershed) regions between major cerebral artery supply are most vulnerable to systemic hypoperfusion

How well did you know this?

Not at all

Perfectly

Define Transient ischemic attack

Transient episode of neurological dysfunction caused by focal brain, spinal cord or retinal ischemia without an acute infarction

Fully reversible neurological deficit lasting < 24 hours with no structural brain damage

NO evidence of infarction on neuroimaging

How well did you know this?

Not at all

Perfectly

Criteria for risk of ischemic stroke following TIA

ABCD2 score (Guidelines by (AHA/ASA)

Estimate the risk of ischemic stroke in the first 2 days after TIA
o Score 0 – 3: Low 2-day stroke risk (1%)
o Score 4 – 5: Moderate 2-day stroke risk (4%)
o Score 6 – 7: High 2-day stroke risk (8%)

How well did you know this?

Not at all

Perfectly

Causes of haemorrhagic stroke

Systemic HTN
Amyloid angiopathy (degenerative)
Hemorrhagic transformation of infarction
Bleeding tendency
Tumor bleeding
AVM, Moyamoya disease
Venous sinus thrombosis
Arterial dissection
Vasculitis

How well did you know this?

Not at all

Perfectly

Incidence of ischemic stroke vs haemorrhagic stroke

Ischemic = 75%

Haemorrhagic = 25%
- SAH <5%
- ICH 20%

How well did you know this?

Not at all

Perfectly

Non-modifiable risk factors of stroke

Advanced age
Higher risk at most ages for men
Higher risk for blacks
Medical history of TIA or stroke
Family history

How well did you know this?

Not at all

Perfectly

Modifiable risk factors of stroke

Hypertension (promotes athersclerosis) - lacunar infarct
Diabetes mellitus - ischemic stroke, carotid atherosclerosis, carotid plaque
Dyslipidemia - ischemic stroke
Smoking - ischemic stroke and SAH
Alcoholism
Oral contraceptive pills

How well did you know this?

Not at all

Perfectly

Etiologies of thrombosis formation in large vessels (intra- and extracranial)

Intracranial:

Atherosclerosis
Arterial dissection
Vasospasm/ Vasoconstriction
Moyamoya disease

Extracranial

Atherosclerosis
Arterial dissection
Vasculitis
Fibromuscular dysplasia (abnormal alternating thick and thin fibromuscular ridges with collagen in vessels/ string on beads sign)

How well did you know this?

Not at all

Perfectly

Etiologies of thrombosis formation in small intracranial vessels

Lipohyalinosis with fibrinoid degeneration
• Lipid deposition and accumulation of foamy macrophages
• Hyalinization and thickening of vessel wall
• Fibrinoid degeneration (necrosis) of vessel wall

Microatheroma

How well did you know this?

Not at all

Perfectly

Etiologies/ sources of emboli causing ischemic stroke

Cardiac causes:

Myocardial infarction
Arrhythmia
Valvular heart diseases: prosthetic valve, infective endocarditis or non-bacterial thrombotic endocarditis
Dilated cardiomyopathy
Atrial or ventricular thrombus
Left atrial myxoma

Aortic cause:
- Atheroma from PAD

How well did you know this?

Not at all

Perfectly

Etiologies of systemic hypoperfusion causing ischemic stroke

 Pump failure
• Cardiac arrest
• Cardiac arrhythmia

 Decreased cardiac output (CO)
• Myocardial infarction (MI)
• Pericardial effusion/ Cardiac tamponade
• Pulmonary embolism

How well did you know this?

Not at all

Perfectly

Etiologies of subarachnoid haemorrhage

Study These Flashcards

□ Trauma: the most common cause of SAH (not aneurysm)

□ Spontaneous SAH:
→ (Berry) aneurysm (75%)
→ Arteriovenous malformation (AVM) (5%)
→ Tumours or bleeding tendency (5%)
→ Idiopathic (15%)

Clinical features of SAH

Study These Flashcards

Headache: characteristically sudden, severe, ‘thunderclap’
→ Often occipital, hours to days

LOC ± seizures

Focal neurological signs

Meningism: neck stiffness, photophobia

Typical description of fundoscopic changes in SAH

Study These Flashcards

papilloedema, subhyaloid haemorrhage*

(haemorrhage into space between hyaloid membrane surrounding the vitreous and retina)*

Typical description of SAH on NECT

Study These Flashcards

Urgent NECT: hyperdensity in subarachnoid space

→ ‘Star sign’: hyperdensity in basal cisterns, Sylvian and interhemispheric fissures
→ Sulcal hyperdensity

Investigations for SAH

Study These Flashcards

Urgent NECT

3 bottle Lumbar puncture if CT negative: Uniformly blood stained progress to Xanthochromia (bilirubin in CSF)

Angiography: digital subtraction angiography

(MRI not sensitive at early stage)

3 Complications of SAH and management

Study These Flashcards

Rebleeding* (days): endovascular coiling and antifibrinolytic agent
Vasospasm* (1 week): blood in CSF trigger arteriole spasm
- Nimodepine (cerebral selective CCB)
- Angioplasty: mechanical or chemical
- Triple-H therapy: Hypertension + Haemodilution + Hypervolemia
Hydrocephalus (months)
- CSF drainage

Others: cerebral oedema, seizures (consider prophylactic anticonvulsants), SIADH, arrhythmia

Management plan for acute ischemic stroke:

Adjuvant
Reperfusion therapy
Medical therapy

Study These Flashcards

Adjuvant:

ABC and ICP control with Mannitol, permissive HTN
Surgical decompression by CSF drainage, decompressive craniectomy

Reperfusion therapy:

IV tissue plasminogen activator (tPA, Alteplase) thrombolysis
Endovascular mechanical thrombectomy (anterior circulation, large arteries only)

Medical therapy:

Antiplatelet: aspirin
(Anticoagulant: only for venous thrombosis, cardioembolism, arterial dissection)

Therapeutic window for IV tPA thrombolysis and endovascular theombectomy in acute ischemic stroke

Study These Flashcards

tPA: 3-4.5 hours from symptom onset

Endovascular thrombectomy: 6 hours from symptom onset

List 3 acute cerebral complications of acute ischemic stroke

Study These Flashcards

→ Oedema, increased ICP, herniation
→ Haemorrhagic transformation of cerebral infarction
→ Seizures

List 3 delayed cerebral complications of ischemic stroke with rapid deterioration in mental status*

Malignant MCA syndrome: vasogenic and cytotxic edema causing large hemispheric infarct in MCA Posterior fossa infarct: obstructive hydrocephalus, coning Haemorrhagic transformation*: reperfusion with disrupted BBB with raised ICP

Haemorrhagic transformation of ischemic stroke - Cause - Time course - S/S - Management

Cause: reperfusion with disrupted BBB → extravasation of blood with ↑ICP S/S: rapid deterioration in mental status (i.e. ↓GCS) on day 1-2 after stroke Mx: → Medical: ABC, elevate bed head, IV mannitol, hyperventilation (salvage) → Surgical: external ventricular drainage, emergency hemicraniectomy

How to manage haemorrhagic transformation of ischemic stroke after tPA thrombolysis?

rtPA-related IC, give prothrombin complex concentrate (PCC)

Cerebral anuerysms: - Sites - Etiologies

Site: usually at arterial bifurcations □ Majority along circle of Willis □ 90% anterior circulation ``` Aetiology: unknown but related to □ Haemodynamic stress □ Connective tissue diseases, eg. Ehler-Danlos, Marfan’s □ Adult polycystic kidney disease □ Coarctation of aorta □ Family history ```

Compare surgical and medical CNIII palsy

Surgical CNIII palsy: due to tumor or aneurysm compression - Peripheral parasympathetic fibers damage - Central fibers intact (eye movement intact) > Dilated pupil and ptosis Medical CNIII palsy: vascular disease e.g. DM - Central fibers damage > Loss of eye movement without ptosis

Surgical treatment options for cerebral anuerysms

Microsurgical clipping Endovascular coiling/ stenting Flow diverter

4 types of cerebral vascular malformations

□ Arteriovenous malformation (AVM): most common, highest bleeding risk □ Cavernous angioma □ Venous angioma □ Capillary telangiectasia

Cerebral AVM - Cause - Pathological consequences

congenital: no capillaries between arteries and veins ``` Pathological consequences: □ Arteriovenous shunting □ Arterialized veins □ Venous varices □ A/w aneurysms ```

Clinical presentation of cerebral AVM

□ Haemorrhage □ Seizures □ Ischaemia due to vascular steal phenomenon □ Headache □ Others: bruit, hydrocephalus, heart failure

Modalities of surgical treatment of cerebral AVM

Modalities: → Surgical excision: usually for smaller AVMs → Embolization of feeder artery: usually for larger AVMs → Radiosurgery: better response for smaller AVMs

Moyamoya disease - Cause - Pathological consequences - Presentation in children and adults - Management

Progressive occlusion of cerebral vasculature, esp CoW and its feeding vessels Fragile collaterals develop late in adulthood → ‘puff-of-smoke’ appearance on angiogram Presentation: □ Ischaemic symptoms in young □ Haemorrhagic symptoms in adults Synangiosis: connection of extracerebral arteries onto pia to allow revascularization of brain

Cervical arterial dissection - 2 major causes - Symptoms - Pathological consequences - Management

Causes: - Spontaneous: connect tissue disorder - Traumatic: neck rotation injury Symptoms: - ICA: retroorbital pain, Horner's syndrome - VA: occipital pain, vertevrobasilar symptoms Consequences: - Ischemia - Dissecting aneurysm rupture and SAH Mx: - Anticoagulant (stable) - Endovascular or bypass surgery

JC30 (Surgery) - Cerebrovascular events Flashcards

(36 cards)