Cerebrovascular accident Flashcards
Examples
(TIA)
Stroke
Types of stroke
Ischaemic
Haemorrhagic
Define cerebrovascular accident
Syndrome of rapid onset of neurological deficit caused by focal, cerebral, spinal or retinal INFARCTION
Characterised by rapidly developing signs of focal or global disturbance of cerebral functions, lasting >24 hours or leading to death
Epidemiology
3rd most common cause of death in high-income countries (11% of UK deaths)
Leading cause of adult disability worldwide
Incidence increases with age
More common in males
Aetiology
Ischaemic/infarction account for 80% of strokes
Haemorrhagic account for 17% of strokes
Others causes 3%
What can cause Ischaemic/infarction that can result in stroke
- Small vessel occlusion/ thrombosis in situ
- Cardiac emboli from AF, MI or infective endocarditis
- Large artery stenosis
- Atherothromboembolism e.g. from carotid
- Hypoperfusion, Vasculitis, Hyperviscosity (polycythaemia + sickle cell)
Causes of haemorrhages that can result in stroke
Trauma Aneurysm rupture Anticoagulation Thrombolysis Carotid artery dissection Subarachnoid haemorrhage
Causes in young people
- Vasculitis
- Thrombophilia
- Subarachnoid haemorrhage
- Carotid artery dissection - spontaneous, or from neck trauma
- Venous sinus thrombosis
Causes in elderly
- Thrombosis in situ
- Athero-thromboembolism
- Heart emboli e.g. AF, infective endocarditis or MI
- CNS bleed
- Sudden BP drop by more than 40mmHg
- Vasculitis
- Venous sinus thrombosis
Risk factors
Male Black/Asian Hypertension Past TIA Smoking DM Old age Heart disease (valvular, ischaemic) Alcohol [Imagine patient with all of this] Polycythaemia, thrombophilia; AF; hypercholestrolaemia; combine oral contraceptive pill; Vasculitis; Infective endocarditis
What % of strokes are ischaemic
70%
Aetiology of ischaemic stroke
Atherosclerosis is main pathological process.
Thrombosis occurs at site of athermatous plaque in carotid/vertebral/cerebral arteries.
Large artery stenosis acts as a source for embolism rather than occluding the vessel.
An occlusive vasculopathy known as lipohyalinosis that is a consequence of hypertension results in small infarcts known as ‘lacunes’ and/or the gradual accumulation of diffuse ischaemic change in deep white matter.
Ischaemic infarction due to occlusion of a vessel, usually by an embolism of a thrombus.
Pathophysiology of ischaemic stroke
Ischaemic -> infarct -> Death of neural tissue -> Loss of functionality
What is the name of the occlusive vasculopathy that results from hypertension and results in the gradual accumulation of diffuse ischaemic change in deep white matter
Lipohyalinosis
What is the name for the gradual accumulation of diffuse ischaemic change in deep white matter
Lacunes
Describe venous sinus thrombosis
Rare
Thrombosis within intracranial venous sinuses, such as the superior sagittal sinus, or in cortical veins
May occur in pregnancy, hypercoaguable states and thrombotic disorders or with dehydration or malignancy
What can result from venous sinus thrombosis
Cortical infarction
Seizures
Raised intracranial pressure
What % of strokes are haemorrhagic
17%
Risk factors of haemorrhagic stroke
Hypertension, excess alcohol, smoking and age
Space occupying lesion e.g. tumour - rare
Pathophysiology of haemorrhagic stroke
Primarily intracerebral haemorrhage
Risk factors -> small vessel disease and aneurysms -> rupture and haemorrhage
Hypertension resulting in micro aneurysm rupture
Aetiology of lobar intercerebral haemorrhage
Deposition of amyloid-B in the walls of small and medium-seized arteries in normotensive patients - particularly over 60
Example of a cause of haemorrhagic stroke in young adults
1/5th strokes are due to carotid/vertebral artery dissection - can occur due to recent neck pain, trauma or neck manipulation
General clinical presentation of ischaemic stroke
Depends on the location of the infarct. Cerebal hemisphere (most common):
Signs contralateral to the affected side. Hemiplegia, hemisensory loss, upper motor neurone facial weakness and hemianopia
Brainstem:
Complex, depending on location
Multi-infarct:
Multiple steps progressing to dementia
Clinical presentation of haemorrhagic stroke
Severe headache, nausea/vomiting.
Sudden loss of consciousness -> Stroke
(similar to ischaemic)
Clinical presentation of stroke of Anterior Cerebral Artery (ACA) Territory
Leg weakness and leg sensory disturbances Gait apraxia Truncal ataxia Incontinence Drowsiness Akinetic mutism
What is apraxia and ataxia
(Gait) Apraxia = Loss of ability to have normal function of lower limbs such as walking
(Truncal) Ataxia = patients cant sit or stand unsupported and tend to fall backwards
Why does stroke affecting the ACA cause drowsiness
since part of consciousness is in the frontal lobe (which the ACA supplies)
What is akinetic mutism
Decrease in spontaneous speech
Stuporous state
Clinical presentation of stroke of Middle Cerebral Artery (MCA) Territory
CONTRALATERAL ARM & LEG WEAKNESS CONTRALATERAL sensory loss Hemianopia Aphasia Dysphasia Facial droop
What are aphasia and dysphasia
Aphasia - inability to understand or produce speech
Dysphasia - deficiency in speech generation
Clinical presentation of stroke of Posterior Cerebral Artery (PCA) Territory
CONTRALATERAL HOMONYMOUS HEMIANOPIA Cortical blindness Visual agnosia Prosopagnosia Colour naming and discriminate problems Unilateral headache (*RARE in ischaemic stroke, so if you see headache then think PCA)
Describe contralateral homonymous hemianopia
loss of half the vision of the same side in both eyes
What is meant by cortical blindness
eye healthy, but brain issue causing blindness
What are:
Visual agnosia
Prosopagnosia
Visual agnosia - cannot interpret visual information, but can see
Prosopagnosia - cannot see faces
Clinical presentation of stroke of Posterior circulation territory such as vertebrobasilar artery
Motor deficits such as hemiparesis or tetraparesis and facial paralysis
Dysarthria (unclear speech articulation) & speech impairment
Vertigo, nausea & vomiting
Visual disturbance
Altered consciousness
Why are posterior circulation stroke more catastrophic
Due to wide region supplied by it
Describe lacunar stroke
Small subcortical strokes e.g. midbrain, internal capsule
Clinical presentation of lacunar stroke
Unilateral weakness (and/or sensory deficit) of face and arm, arm and leg or all three Pure sensory loss Ataxic hemiparesis (cerebellar and motor symptoms)
In general only 1 modality tends to be affected
True or False:
No reliable way of distinguishing between haemorrhage and ischaemic infarcts
When could you assume otherwise
True
- Intracerebral haemorrhage is more often associated with severe headache or coma (signs of raised intracranial pressure (ICP) i.e. due to blood forming space-occupying lesion)
- Patients on oral anticoagulants should be assumed to have had a haemorrhage unless it is proved otherwise
Differential diagnosis
Always EXCLUDE hypoglycaemia as a cause of sudden onset neurological syndrome
Hypoglycaemia
Migraine aura (symptoms spread and intensify over minutes, often with visual scintillations (sparkling/blinking))
Focal epilepsy
Intracranial lesion - tumour or subdural haemotoma
Syncope due to arrhythmia
What is syncope
Temporary loss of consciousness usually related to insufficient blood flow to the brain
(AKA fainting)
Diagnosis
Urgent CT head/MRI head BEFORE TREATMENT (CT to confirm ischaemic)
Pulse, BP and ECG - look for AF
Bloods - FBC, Glucose
Why is it important to be careful in treating high BP
Even a 20% fall in BP may compromise cerebral perfusion
Why are bloods done in diagnosis (FBC and glucose)
FBC - look for thrombocytopenia and polycythaemia
Blood glucose - to rule out hypoglycaemia
When is CT head/MRI urgent
If suspected cerebellar stroke, unusual presentation (i.e. alternative diagnosis likely), high risk of haemorrhage (low GCS and signs of raised ICP)
Rule out haemorrhagic stroke before starting thrombolysis
Treatment
Aspirin
IV alteplase in at least 4.5 hours (thrombolytic; IV tissue plasminogen activator)
Antiplatelet (aspirin -> Lifelong Clopidogrel)
Maintain glucose
NBM (Nil By Mouth)
Ensure hydration and keep O2 stats > 95%
Stop anticoagulants (Haemorrhagic)
Describe risk factor management for stroke prevention
Platelet treatment (lifelong if already had stroke) e.g. ASPIRIN + DIPYRIDAMOLE or CLOPIDOGREL
Cholesterol treatment like statins e.g. SIMVASTATIN
Atrial fibrillation treatment e.g. WARFARIN or new oral anticoagulants e.g. PIXIBAN
Blood pressure treatment e.g. ACE-inhibitor e.g. RAMIPRIL
Why is it important to ensure hydration and keep O2 stats > 95%
Maximise reversible ischaemic tissue
Haemorrhagic treatment
Frequent GCS monitoring
Antiplatelets contraindicated
Any anticoagulants should be reversed for Warfarin reversal use BERIPLEX and VITAMIN K
Control hypertension
Manual decompression of raised ICP, can also reduce ICP by giving
diuretic e.g. MANNITOL
Surgery may be required
Called by paramedics to inform you there is a 65 yr old RIGHT HANDED man who presents with a RIGHT SIDED WEAKNESS of BOTH ARMS & LEGS, DYSARTHRIA, LOSS OF VISION and DIFFICULTY SPEAKING
- Paramedics say symptoms came on SUDDENLY at 13:30
- Time is now 15:00
Diagnosis and treatment?
Diagnosis:
Likely to be MCA stroke since BOTH arms & legs involved
Treatment:
Within the 4.5 hour time frame for thrombolysis (alteplase) as long as CT head confirms ischaemic and no contraindications
What is Clopidogrel
P2Y12 inhibitor
Antiplatelet drug
