Stroke and TIA Flashcards
What is a stroke
Stroke – focal cerebral hypoperfusion resulting in reduced ATP and so sudden cessation of action potentials. This can either be due to haemorrhage (13%) or ischaemia (87%)
Describe the main causes of stroke
Large-artery atherosclerosis
Carotid artery Stenosis
Carotid Dissection most common cause in young adults
Cardio-embolic
Atrial fibrillation
Giant cell Arteritis
Small vessel disease
Hypertension causing haemorrhagic stroke and/or atherosclerosis
Amyloid Bleeds
What are the 5 stroke syndrome features
Sudden Onset Focal neurological signs Loss of function (i.e. not pain) also known as negative symptoms Attributable to a vascular territory Maximal at onset
Describe common stroke presentations
Most commonly present with unilateral limb weakness or loss of sensation, facial droop, dysphasia (left side), neglect (right side), visual field loss, loss of coordination.
Slurred speech, difficulty swallowing, and diplopia are not focal signs and must have other signs to be considered for a stroke.
Also note that symptoms that migrate are unlikely to be due to stroke and more likely stroke mimic especially with sensory or visual disturbances e.g. migraine and seizure. As well as this stereotyping of symptoms are extremely unlikely to be due to a stroke. There are 2 exceptions to these rules - capsular warning syndrome and intracranial stenosis
What is capsular warning syndrome
Capsular warning syndrome – hypoperfusion in the lenticulostriate end arteries can occur if blood flow through the MCA is reduced. This can cause intermittent and fluctuating impairments – can be confirmed as capsular warning syndrome on MRI.
What is intracranial stenosis
Intracranial stenosis – stereotyping can also be seen when intracranial stenosis interacts with another cause of generalised cerebral hypoperfusion e.g. palpitations, postural hypotension etc. Angiography can confirm stenosis.
Can you distinguish between hemorrhagic and ischaemic stroke by presentaiton?
It is impossible to distinguish between a haemorrhagic and ischaemic stroke clinically however haemorrhagic strokes are more like the present with • Loss of consciousness • Headache • Nausea and vomiting • Seizures
Describe the oxford community stroke project classification of TACS
TACS (total anterior circulation stroke)
All 3 of the following being present:
• Higher dysfunction – dysphasia, visuospatial disturbances
• Homonymous hemianopia
• Motor and/or sensory defects of face, arm or leg
Describe the oxford community stroke project classification of PACS
PACS (partial anterior circulation stroke)
Isolated higher cortical dysfunction or
2 out of
• Higher dysfunction – dysphasia or visuospatial disturbances
• Homonymous Hemianopia
• Motor and/or sensory defects of face, arm or leg
Note motor and/or sensory defect of only one somatic region i.e. face, arm or leg can only be a PACS due to vascular territories.
Describe the oxford community stroke project classification of LACS
LACS (Lacunar stroke) – perforating end arteries around the basal ganglia, internal capsule or thalamus presenting with one of
• Unilateral weakness and/or sensory deficit of 2/3 or more of face, arm or leg
• Ataxic hemiparesis
Describe the oxford community stroke project classification of POCS
POCS (Posterior circulation syndrome)
• Isolated homonymous hemianopia with macular sparing
• Cerebellar or brainstem stroke (bilateral signs or locked in syndrome)
• Ipsilateral cranial nerve palsies with contralateral motor and/or sensory deficit
What signs and symptoms do cerebellar strokes cause?
Cerebellar strokes – DANISH especially coordination, precision and timing. Can include the brainstem if blockage is proximal.
ISPILATERAL SIGNS
Describe the signs seen in brain-stem strokes?
Brainstem will illicit contralateral signs if tracts are affected, ipsilateral if cranial nerve nuclei are affected.
How does the location in a basilar artery stroke change its presentation?
Basilar artery – Distal occlusion causes bilateral occipital lobe infarction, bilateral thalamic infarction, bilateral midbrain involvement. Proximal occlusion causes ’locked-in-syndrome’.
How does a thalamic stroke present?
Thalamic Stroke – contralateral sensory signs only of all modalities that will be isolated to certain parts of the body (more commonly due to atherosclerosis than due to emboli).
What is Weber’s syndrome?
Weber’s Syndrome – branch of the posterior cerebral artery that supplies the midbrain causing ipsilateral CN III palsy and contralateral weakness of the upper and lower limbs.
What is lateral meduallary syndrome/Wallenberg Syndrome?
Lateral medullary syndrome or Wallenberg syndrome – posterior inferior cerebellar infarct causing ipsilateral facial pain and temperature loss, ataxia, nystagmus, dysphagia and CN palsies, contralateral limb/torso pain and temperature loss.
What immediate investigations is required for a suspected stroke?
NIHSS score is very important for stroke management
CT scan (non-contrast) to rule out haemorrhagic stroke allowing thrombolysis if eligible MRI later on to look for stroke if CT showed nothing (CT will only show large ischaemic stroke acutely)
On the CT you’ll see Hyperattenuation, effacement of sulci and obscuration – loss of grey-white matter border.
