Stroke Flashcards
What does the Basal Ganglia control?
Voluntary Motor Function
higher cortical functions - processes sensory info etc
Types of Stroke
Ischemic - due to disrupted blood supply such as thrombus
Haemorrhage - bleeding in or around the brain
How do you assess facial weakness? What causes facial weakness?
Ask them to smile
Testing lower facial muscles
Upper facial muscles has contralateral control
facial nerve; number 7
upper motor neuron in upper cortex
lower motor neuron in the pons
What is rTPA?
aka Alteplase
is a thrombolysis treatment that dissloves blood clots
What are contraindications to thrombolysis
Clinical diagnosis of stroke in doubt
Taking anticoagulants or **INR over 1.7 **
Hx of bleeding
Possible subarachnoid haemorrhage
**Stroke symptoms longer then 4.5hrs **
What is a carotid endartectomy?
Removal of atheroscleosis from the vessel wall to prevent (further) stroke
Which type of matter is myelinated?
White matter
What do hypoxic/ischemic neurons look like under the microscope?
Red nerve cells
weeks - Microglia (macrophages)
months/year - liquifactive necrosis - depression filled with CS fluid
What does Warfrin act on?
Vit K antagonist
Protein S, Protein C
Factor II, VII, IX, X
What is the Glasgow Comma Scale?
Three aspects of behaviour that are independently measured as part of an assessment of a patient’s GCS – motor responsiveness, verbal performance and eye-opening.
The highest possible score is 15 (fully conscious) and the lowest possible score is 3 (coma or dead).
What are risk factors for TIA?
- African descent
- Male
- Increased age
- FHX of TIA & Stroke
- HTN & atherosclerosis
- Diabetes
- Obesity & OSA
- high LDL, low HDL
- Cocaine abuse
- Smoking
Explain the pathophysiology behind TIA?
Blood vessel occlusion/stenosis/hypo-perfusion leads to decreased blood flow in the affected region. Leads to short lasting neurological dysfunction and stroke-like symptoms.
Blockage self-resolves within 24hrs
What is the presentation for TIA?
Symptoms usually last a few mins to 1 hour (within 24 hours at the most)
* Numbness/paresis
* Face, arms, legs etc
* Aphasia - If dominant hemisphere affected
* Hemispatial neglect - If non-dominant hemisphere affected
* Dizziness
* Double vision
* Amaurosis fugax - If affecting ophthalmic artery
* Focal hearing loss
Investigations for TIA?
Bloods; To rule out conditions that mimic TIA
* Hypoglycaemia, hyponatraemia, thrombocytosis
CT/MR/conventional catheter angiography
Diffusion-weighted MRI scan - Changes seen within first few hours of symptoms
Perfusion-weighted MRI - Checks for decreased tissue blood flow
Everyone presenting with stroke or TIA should be
given a neck doppler ultrasound and ECG; To rule out carotid stenosis and AF respectively
If there is >50% stenosis of vessel -> carotid
endarterectomy
ABCD2 score
* To evaluate risk for possible ischaemic stroke
* Age, Bp, Clincial feature, Duration, Diabetes
Management of TIA
Early presentation - < 24hrs
Aspirin 300mg stat, 75mg OD for 21 days
Clopidogrel 300mg stat, 75mg OD lifelong
Late presentation - > 7days
Aspiring 300mg stat, 75mg OD till seen by specialist
Clopidogrel 300mg stat, 75mg OD lifelong
Lifestyle modifications, BP control, Lipid control, Anticoag in AFib
What is the advice around driving for all Strokes & TIAs?
Advise not to drive;
1 month if only 1 event
3 months if HX of multiple events
What is the prognosis of TIA?
Recurrent TIA or ischemic stroke
ABCD2 - to work out risk of stroke in week following TIA
What are the 3 branches of the Internal Carotid? And where do they supply?
The anterior carotid generally supples the anterior portion of the brain
1. Opthalmic artery - supplies the retina
2. Anterior cerebral artery - supplies the frontal lobe & superior parietal lobe
3. Middle cerebral artery - supplies the rest of the parietal lobe and portions of the frontal & temporal lobe
What does the vertebrobasilar artery supply?
posterior portion of the cerebrum & cerebellum
What does the posterior cerebral artery supply? What is the origin of the PCA?
Occipital and posteromedial parts of the temporal lobe
The PCA lies just above the circle of Willis so comes of the basilar artery
What comes off the Basilar artery?
Posterior cerebral artery
Anterior cerebellar artery - supply the cerebellar
Superior cerebellar artery - supply the cerebellar
What artery causes locked in syndrome?
Basilar artery
What artery is blocked with thalamic pain syndrome and burning pain on the contralateral side of the body?
Posterior cerebral artery
What artery is blocked when there is behavioural changes and weakness/paralysis of the leg over the arm
difficulty forming words, often shows struggle in speaking
Anterior Cerebral Artery
What are specific symptoms associated with a blockage of the middle cerebral artery?
Difficulty understanding words and instructions, Gaze preference
towards the side of the lesion and Paralysis/weakness of the arm over the leg or total
contralateral hemiparesis
What is a Lacunar stroke?
A Lacunar stroke is a stroke that affects the subcortical structures of the braindue to damage to the branches of the main circulation such as the MCA. This leads to specific symptom disorders depending on the location of the stroke. It also leads to no higher cerebral dysfunctions such as Dysphasia.