Medicine: Cerebrovascular disease Flashcards
New definition of TIA
* even short periods of ischaemia can lead to permanent changes → therefore a new ‘tissue-based’ definition rather than a ‘time-based’
‘Tissue-based’ definition: a transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischaemia, without acute infarction.
New definition of stroke
Sudden onset of a focal neurological deficit, lasting more than 24 hours (or leading to death) due to either infarction (85%) or haemorrhage (15%)
What’s ROSIER score?
Describe it
ROSIER it’s a variant of FACE used by medical professionals
- Total Score > 0 (1-6) = Acute Stroke is likely
- Total Score 0, -1 or -2 = Stroke unlikely (Discuss with Stroke Team)
First-line investigation for a suspected stroke
A non-contrast CT head scan is the first-line radiological investigation for suspected stroke
Anatomy of circle of Willis
What’ total anterior circulation stroke
Total Anterior Circulation Stroke (TACS)
•Hemiparesis +/- hemisensory loss
AND
•Homonymous hemianopia
AND
•Cortical dysfunction (dysphasia /perceptual problem)
What’s that?
Total Anterior Circulation Stroke
What’s that?
Clot in left middle cerebral artery (MCA)
What’s partial circulation stroke?
- 2 of the 3 below:
- Hemiparesis +/- hemisensory loss
- Homonymous hemianopia
- Cortical dysfunction (dysphasia / perceptual problem)
- OR
- Cortical dysfunction alone
What’s that?
Partial anterior circulation stroke
What’s a lacunar stroke? (criteria)
LACUNAR STROKE (LACS)
• Hemiparesis
OR
• Hemisensory loss
OR
• Hemisensorymotor loss
OR
•Ataxic hemiparesis
* No cortical dysfunction or hemianopia *
What’s that?
Lacunar stroke
Signs and symptoms of Posterior Circulation Stroke
Posterior Circulation Stroke (POCS)
- Brainstem nuclei or cerebellar signs & symptoms
- Occipital signs
Presentation:
•Diplopia, vertigo, ataxia, bilateral limb problems, hemianopia, cortical blindness
What’s that?
Posterior circulation stroke
Acute Mx of stroke
- CT Brain
- Bloods
- ECG
- CXR
- Aspirin 300mg ASAP (PO/PR/NG) – if no bleed on scan
- Stroke Unit
Mx of a stroke at stroke unit
- Careful monitoring and correction of physiological parameters
- Hypoxia / Glucose / Blood pressure / Pyrexia
- Early SALT input
- Early feeding
- Physiotherapy and rehab
- Psychology input
What’s the Modified Rankin Scale?
Commonly used measure of disability / dependence in people who have suffered a stroke or other causes of neurological disability
0 - No symptoms
1 - No significant disability. Able to carry out all usual activities, despite some symptoms
2 - Slight disability. Able to look after own affairs without assistance, but unable to carry out all previous activities.
3 - Moderate disability. Requires some help, but able to walk unassisted.
4 - Moderately severe disability. Unable to attend to own bodily needs without assistance, and unable to walk unassisted
5 - Severe disability. Requires constant nursing care and attention, bedridden, incontinent
6 - Dead
Power grading in neurological examination
Secondary prevention of stroke
- Clopidogrel 75mg od, after 2 weeks of Aspirin 300mg od
- Cholesterol control (target < 4.0) - Statin
- BP Control (target < 130/80)
- Screen for and treat diabetes
- Smoking cessation
- Screen for and treat carotid stenosis
- Screen for and manage AF (anticoagulation)
- Echocardiogram
What’s the driving restriction post-stroke?
Driving restrictions (DVLA): Car – 1 month off driving if good functional recovery
What’s the ischaemic core?
ISCHAEMIC CORE (irreversible damage) :
Area of brain tissue local to the blood vessel occlusion, whose blood supply is entirely supplied by this vessel, dies.
What’s Ischaemic Penumbra?
ISCHAEMIC PENUMBRA (SALVAGEABLE TISSUE):
- Surrounding the ischaemic core is an area with some collateral blood supply (blood flow is reduced)
- Without intervention much of this will also die
- Over subsequent hours this area either becomes viable again, or forms part of the ischaemic core.
Role/considerations in the hyperacute treatment of stroke
- Earlier treatment = better outcomes
- Ischaemic penumbra is likely to be larger
- As the penumbra disappears, stroke therapy such as thrombolysis becomes ineffective
- Most patients no longer have a penumbra beyond 4.5 hours
- Ischaemic core becomes more friable
- Risk of bleeding is higher & usually outweighs benefits of thrombolysis
Management of stroke with thrombolysis
- drug used
- timeframe
- what must be done before treatment
- possible complications
- when to repeat CT
- IV Alteplase
- Bolus – 10% of total dose (0.9mg/kg)
- Infusion over 1 hour (remainder of drug)
- Given within 4.5 hours of symptom onset
- Urgent CT brain to exclude bleed prior to treatment
- Complications include bleeding & angio-oedema
- Repeat CT Brain at 24 hours
What’s thrombectomy?
- timeframe
- complications
Thrombectomy = Mechanical Clot Retrieval
• offered up to 6 hours post symptom onset
- Can be as 1st line but usually as 2nd line treatment after failed thrombolysis
- Risk of serious complications: Intracranial haemorrhage / access site complications / vessel perforation / distal emboli
Thrombectomy procedure - describe
Procedure:
- Under sedation (Local or General anaesthesia)
- Initially, patient undergoes conventional cerebral angiography: demonstrates presence & location of arterial occlusion
- Delivery catheter inserted (usually through femoral artery) & advanced using X-ray guidance to occluded vessel
- Clot retrieval device attached to a guidewire is introduced through the delivery catheter to the occlusion site
Ix in deteriorating stroke patient
- ABCDE
- Blood glucose
- GCS and Neurological examination
- Bloods - Consider aspiration / infection
- Urgent CT Brain
What’s the scan present?
Intracerebral haemorrhage with surrounding oedema and midline shift
What’s the scan present?
Malignant MCA Syndrome
ABCD2 scoring system
- Age > 60 = 1
- BP > 140/90 = 1
- Clinical – speech disturbance (1), unilateral weakness (2)
- Duration – 10 mins to 59 mins (1), 1hr + (2)
- Diabetes = 1
1-3 = 2-day risk of 1%, 7 day risk of 1.2%
4-5 = 2-day risk of 4%, 7 day risk of 6%
>5 = 2-day risk of 8%, 7 day risk of 12%
Why seizures and transient LOC are not usually indicative of a stroke?
- stroke does not cause seizures ACUTELY → however possible to cause seizures later on due to fibrosis of the dead tissue etc
- stroke does not cause transient LOC/syncope → if stroke causes LOC it would be more long-term like
What do we with high BP in acute ischaemic stroke?
- do not lower BP → sometimes high BP needed to maintain perfusion
- lower BP → if thrombolysis is indicated
What to do with high BP in acute haemorrhagic stroke?
lower BP gradually
Stroke differentials
- post- seizure Todd Paresis → is a focal weakness in a part or all of the body after a seizure. This weakness typically affects appendages and is localized to either the left or right side of the body. It usually subsides completely within 48 hours
- Bell’s Palsy
- migraine
How to differentiate between stroke vs Bell’s Palsy
- Bell’s Palsy is LMN → therefore both, forehead + face affected
- Stroke is UMN → forehead sparing
How to differentiate between haemorrhagic and ischaemic stroke on CT scan?
