CVA/stroke

Question 1

What is cerebrospinal-vascular disease?

Answer 1

High morbidity & mortality
Typically manifests with abrupt focal neurological deficit
Common cerebrovascular disorders include:
• IschaemicStroke
• HaemorrhagicStroke
Common cerebrovascular anomalies include: • Intracranialaneurysms
• Arteriovenous Malformations (AVM)

Question 2

What is a stroke?

Answer 2

• Second most common cause of death in the World
• Stroke kills more women than breast cancer and more men than prostate cancer
• Leading cause of adult disability
• In Australia 56,000 new and recurrent strokes this year– that is one stroke every nine minutes.
• 30% stroke survivors under 65
• 65% of stroke survivors suffer a disability which impedes
their ability to carry out daily living activities unassisted.
• The financial cost of stroke in Australia is estimated to be $5 billion each year
• More than 80% of strokes can be prevented
• Medical emergency

Question 3

What percentage of CVA is haemorrhagic and non-haemorrhagic?

Answer 3

15% is haemorrhagic

85% is non-hemorrhagic

Question 4

What is a TIA?

Answer 4

Transient Ischemic Attack

• “Angina” of the brain
• Focal neurological event lasting <24 hours
• Focal loss of central nervous function due to decreased blood flow to part of the brain
• Transient in nature
• High risk of CVA – precursor or warning event!
• Image…?? Brain – Carotids – Heart

Question 5

CVA signs and symptoms

Answer 5

• Abrupt onset of hemiparesis, monoparesis, or (rarely) quadriparesis • Hemisensory deficits
• Monocular or binocular visual loss
• Visual field deficits
• Diplopia
• Dysarthria (unable to articulate speech)
• Facial droop
• Ataxia (lack of muscle control)
• Vertigo (rarely in isolation)
• Nystagmus (involuntary eye movement)
• Aphasia (unable to understand or produce speech) • Sudden decrease in level of consciousness

Question 6

CVA diagnosis

Answer 6

• Medical history / Risk factors
• Physical examination
• Airway and breathing
• Reflexes, muscle strength, senses, and coordination
• Listen for sounds from any blockages of the arteries in the carotids • Blood pressure
• Listen to heart abnormal rhythm / sounds
• Blood tests
• ECG
• Imaging tests

Question 7

CVA rise factors

Answer 7

Nonmodifiable
• Age
• Race / Ethnicity
• Sex (female)
• History of migraine headaches
• Fibromuscular dysplasia
• Heredity: Family history of stroke or transient ischemic attacks (TIAs)

Modifiable
• Hypertension (the most important)
• Diabetes mellitus
• Cardiac disease: Atrial fibrillation, valvular disease, heart failure, mitral stenosis, structural anomalies allowing right-to-left shunting (eg, patent foramen ovale), and atrial and ventricular enlargement
• Hypercholesterolemia
• Transient ischemic attacks (TIA) • Carotid stenosis
• Lifestyle issues: Excessive alcohol intake, tobacco use, illicit drug use, physical inactivity
• Obesity
• Oral contraceptive use/postmenopausal hormone use

Question 8

Ischaemic stroke phases/stages

Answer 8

• Acute phase/stage (0 to 24/48 hours) (acute ischaemia, neutron death, cytotoxic and extracellular vascular oedema)
• Subacute phase/stage (24/48 + hours) (reparative process begins, resorption of necrotic tissue begins)
• Chronic phase/stage (4 to 6 + weeks) (resorption of necrotic tissues is complete, encephalomalacia or cystic cavity is formed)

Question 9

Vascular territories (over 50% of strokes involve which region of the brain?)

Answer 9

The MCA (middle cerebral artery)

Question 10

Cerebral perfusion

Answer 10

• The brain uses approximately 20% of the available oxygen for normal function
• Cerebral Perfusion includes:
• Cerebral Blood Volume (CBV) – volume blood in amount per 100g of brain tissue
• Cerebral Blood Flow (CBF) – blood supply brain tissue in a given time (usually ml per 100g per min)
• Auto-regulation of CBV & CBF is important
• In a healthy person CBF is remarkably constant

Question 11

Types of ismchaemic stroke

Answer 11

• Large vessel
• Small vessel – Lacunar infarcts
• Thrombotic – from within the brain • Embolic – outside the brain

Question 12

Small vessel - lacunar infarcts

Answer 12

• Occlusion of small sub-cortical non-branching arteries (<15-20mm)
• Occur most frequently in the basal ganglia and in the internal capsule,
thalamus, corona radiata, and pons
• Accounts for around 20% of ischaemic strokes
• Symptomatic or non-symptomatic
• Higher risk of more serious large vessel stroke

Question 13

Large vessel

Answer 13

Occlusion of large artery in the brain
• Thrombotic origin most common
• MCA most commonly occluded major artery • Clinical emergency

Question 14

Haemorrage stroke

Answer 14

• Approximately 15% of all strokes

* Poor prognosis compared to ischaemic stroke • Requires rapid intervention

Question 15

Imaging for a stroke

Answer 15

• Plays major role in patient treatment and diagnosis of brain injury.
• CT
• MRI
• Ultrasound
• Catheter Angiography (DSA)
• PET / SPECT
• X-ray

Question 16

Diagnostic imaging for a stroke

Answer 16

Purpose:
DIAGNOSTIC IMAGING
1. Confirm clinical diagnosis
2. Distinguish between haemorrhagic & thromboembolic ischaemia
3. Identify underlying cause of disease e.g. stenosis/occlusion in CVA
4. Direct management/intervention e.g. thrombolytic therapy in CVA

Question 17

Ideal diagnostic test for a stroke

Answer 17

• 24/7 Availability?
• Safe for acutely ill patients?
• Quick?… ‘Time is Brain’
• Sensitive to cerebral haemorrhage and be able to exclude other differentials?
• Demonstrate anatomical and pathophysiologic aspects of hyper-acute stroke?
• Demonstrate salvageable brain tissue?
• Demonstrate vasculature?
– Vessel occlusion and location
– Origin of emboli or thrombus location/type

Question 18

CT for a stroke

Answer 18

Non-contrast
• Fast +++
• Available 24/7
• Safe
• Sensitive for haemorrhage
Contrast
• Demonstrate vessels
• Demonstrate perfusion