Stroke Flashcards
What are the 4 types of haemorrhagic stroke?
Haemorrhagic = 15%
Primary intracerebral haemorrhage:
- hypertension
- amyloid angiopathy
Secondary intracerebral haemorrhage:
-AVN
Aneurysm
Tumour
What are the 4 types of ischaemic stroke?
Ischaemic = 85%
Atherothrombosis: thrombus lodges in a cerebral artery from another location (white thrombus - platelet dependant)
Cardioembolic (red thrombus - slow blood flow)
Small vessel disease
Large vessel atherosclerosis
-usually acute on chronic with series of TIAs
What score can be used if stroke is suspected?
Rosier score:
-Has there been loss of consciousness or syncope (yes = -1)
Has there been seizure activity (yes = -1)
Is there a new onset (or waking from sleep) of:
Asymmetric facial weakness (y = +1)
Asymmetric arm weakness (Y=+1)
Asymmetric leg weakness (Y= +1)
Speech disturbance (Y = +1)
Visual field defect (Y = +1)
Stroke is likely if total score > 0
Scores of < / = 0 have low probability of stroke but not excluded
What is the 4 parts to the diagnosis of stroke?
Type of stroke – haemorrhagic or ischaemic?
CT scan differentiates
Size of stroke – oxford classification: TACS/PACS/LACS/LACS/POCS
Laterality of stroke – right or left side of brain
- Dominant hemisphere (if left handed is right hand side) – cortical events often affect language and rehab is difficult
- Non-dominant hemisphere cortical events affect spatial awareness
Cause of stroke
What is TACS?
Total anterior circulation syndrome = Large area of cortex
Comprises 20% of strokes with new onset of:
- Hemiplegia involving at least two of face, arm and leg +/- hemisensory loss
- Homonymous hemianopia
- Cortical signs (higher cortical dysfunction – language/neglect)
- Most severe type of stroke with only 5% alive and independent at 1year
What is PACS?
Partial anterior circulation syndrome =Cortex much less involved
Comprises 30% strokes and have to have 2 out of 3 features present in TACS or:
Isolated cortical dysfunction such as dysphasia
Or
Pure motor/sensory signs less severe than in lacunar syndromes e.g. monoparesis
About 55% patients alive and independent at 1 year
What is LACS?
Small infarct:
25% strokes
lacunar infarcts are small infarct in the deeper part parts of the brain and in the brainstem
- basal ganglia
- thalamus
- white matter
caused by occlusion of a single deep penetrating artery
affect to any 2 of face, arm and leg
What are the 4 main patterns of LACS?
best prognosis of all the strokes – 60% pt.s alive and independent at 1 year
4 main patterns:
- pure motor hemiparesis -hemisensorimotor
- ataxic hemiparesis – dysarthria and a clumsy hand
- pure hemisensory
(not all lacunar events cause lacunar syndromes)
What is POCS?
post. Circulation feeds base of brain and midbrain so range of deficits seen
25% strokes and overlap with lacunar strokes
- cranial nerve palsys
- bilateral motor and/or sensory deficits
- conjugate eye movement disorders
- isolated homonymous hemianopia
- cortical blindness
- cerebellar deficits without ipsilateral motor/sensory signs
Management of acute stroke:
- what needs to be kept within normal limits?
- should blood pressure be lowered?
- What should be given if a haemorrhagic stroke has been excluded?
- What is done regarding anticoagulation in AF
- when is a statin started?
blood glucose, hydration, oxygen saturation and temperature should be maintained within normal limits
blood pressure should not be lowered in the acute phase unless there are complications e.g. Hypertensive encephalopathy*
aspirin 300mg orally or rectally should be given as soon as possible if a haemorrhagic stroke has been excluded
-Aspirin 300 mg daily should be commenced within 48 hours of ischaemic stroke and continued for at least 14 days.
with regards to atrial fibrillation, the RCP state: ‘anticoagulants should not be started until brain imaging has excluded haemorrhage, and usually not until 14 days have passed from the onset of an ischaemic stroke’
A statin should be prescribed to patients who have had an ischaemic stroke, irrespective of cholesterol level. Many physicians will delay treatment until after at least 48 hours due to the risk of haemorrhagic transformation
What thrombolysis can be used and when is this used?
Thrombolysis should only be given if:
it is administered within 4.5 hours of onset of stroke symptoms (unless as part of a clinical trial) haemorrhage has been definitively excluded (i.e. Imaging has been performed)
rt-PA is used
What are absolute contraindications to thombolysis?
- Previous intracranial haemorrhage
- Seizure at onset of stroke
- Intracranial neoplasm
- Suspected subarachnoid haemorrhage
- Stroke or traumatic brain injury in preceding 3 months
- Lumbar puncture in preceding 7 days
- Gastrointestinal haemorrhage in preceding 3 weeks
- Active bleeding
- Pregnancy
- Oesophageal varices
- Uncontrolled hypertension >200/120mmHg
What are relative contraindications to thrombolysis?
- Concurrent anticoagulation (INR >1.7)
- Haemorrhagic diathesis
- Active diabetic haemorrhagic retinopathy
- Suspected intracardiac thrombus
- Major surgery / trauma in preceding 2 weeks
What imaging is used in suspected stroke?
CT scanning is recommended for most patients in the acute
phase of stroke.
MRI with diffusion weighted and gradient echo sequences is
recommended
(where available and practical) for the diagnosis
of acute stroke syndromes in patients who:
are not severely ill, especially where either neurological
deficit is mild and the clinical likelihood is that the lesion is
small or lies in the posterior fossa
present late (after one week)
What investigations are used in stroke?
Full lipid profile
Blood pressure Carotid scan – identify and quantify carotid artery stenosis, may detect a dissection Blood pressure ECG Consider 24hour ECG (or longer) echo-cardiogram – possible embolic source of stroke
When is a carotid scan done?
All patients with non-disabling acute stroke syndrome/TIA in
the carotid territory who are potential candidates for carotid
surgery should have carotid imaging.
Initial carotid imaging with duplex ultrasound or alternative
should be performed rapidly once a diagnosis of ischaemic
stroke or TIA in the carotid territory is made.
Initial carotid imaging should be performed within 48 hours of presentation
When would a cartoid endarterectomy be indicated? when should this be done?
Carotid endarterectomy
(on the internal carotid artery ipsilateral to the cerebrovascular event)
should be considered
in all:
male patients with a carotid artery stenosis of 50-99%
female patients with a carotid artery stenosis of 70-99%
Do this as soon as pt is stable and fit for surgery ideally within 2 weeks
What is used for secondary prevention of stroke?
- antiplatelet
- antihypertensive
Low-dose aspirin (75 mg daily) and dipyridamole (200 mg modified release twice daily) should be prescribed after ischaemic stroke or TIA for secondary prevention of vascular events.
dose titration of dipyridamole may help to reduce the
incidence of headache.
Clopidogrel
(75mg daily)
monotherapy should be considered
as an alternative to combination aspirin and dipyridamole
after ischaemic stroke or TIA for secondary prevention of
vascular events.
All patients with a previous stroke or TIA should be
considered for treatment with an ACE inhibitor and thiazide
regardless of blood pressure, unless contraindicated
What is a TIA?
‘mini-stroke’
less than 24 hours
What is the management of a TIA?
rapid access neurovascular clinic:
Rapid assessment:
History Carotid imaging ECG Blood tests Diagnosis Immediate therapy: medication/carotid endarterectomy
What is used for stroke risk prediction in those with a TIA?
A – age greater than 60 = 1
B – blood pressure = 1
C – clinical features
Unilateral weakness = 2
Speech disturbance without weakness = 1
Other = 0
D – duration of symptoms
> 60 = 2
10-59 = 1
<10 = 0
D – diabetes = 1
More than or equal to five = high risk
What is webers syndrome?
left 3rd nerve palsy and contralateral hemiparesis
lesion is localised to midbrain at centre of third nerve nucleus
region is supplied by paramedian branches of the basilar artery or branches of the posterior cerebral artery
What is lateral medullary syndrome?
- caused by?
- arterial supply?
Caused by infarction of the lateral portion of the medulla oblongata
Supplied by the posterior inferior cerebellar artery or the vertebral artery
loss of pain/temp sensation contralateral side of body and ipsilateral side of face
dysphagia/dysarthria/vertigo/nystagmus
