cerebrovascular disease Flashcards
what is the difference between a stroke and a TIA
TIA symptoms resolve within 24 hours
what are the 2 types of stroke
haemorrhagic
ischaemic
which is the more common type of stroke
ischaemic
what is an ischaemic stroke
when blood supply in a cerebral vascular territory is reduced due to stenosis or complete occlusion of a cerebral artery
what classification is used for the causes of ischaemic stroke
TOAST
what is included in the toast classification
large artery atherosclerosis
cardioembolism
small vessel disease
stroke of other determined aetiology
stroke of undetermined aetiology
what would make a stroke have undetermined aetiology
if there are > 2 potential causes identified or incomplete evaluation
how do small vessel disease strokes present
as lacunar infarcts
what causes small vessel disease strokes
lipohyalinosis
what is a cryptogenic stroke
no identifiable cause even with extensive investigation
what is a haemorrhagic stroke
where there is a rupture of a cerebrospinal artery
name some risk factors for haemorrhagic stroke
trauma, neck manipulation
female gender
connective tissue disease, URTI, migraine
name some risk factors for ischaemic stroke
age, male sex, FHx, hypertension, smoking, DM, AF
what is the most common cause of a young stroke and why
patent foramen ovale
blood clots bypass the lungs and travel to the brain
how would we identify a patent foramen ovale
transthoracic echocardiogram
what is a penumbra
area of brain with reduced cerebral blood flow, but getting O2 and glucose from collateral arteries
what are symptoms of a stroke affecting the anterior or middle cerebral artery
numbness, sudden muscle weakness
where is broca’s area found
left frontal lobe
what is a sign of a stroke affecting broca’s area
slurred speech
where is wenicke’s area
left temporal lobe
what is a sign that a stroke has affected wenicke’s area
difficulty understanding speech
what is a sign of a posterior cerebral artery stroke
vision affected
what are some general symptoms of a stroke
SUDDEN
weakness of limbs
facial weakness
dysphasia
visual or sensory loss
what is a rare but classic presentation of basilar artery syndrome
locked in syndrome
what movement can a patient with locked-in syndrome produce
blinking and vertical eye movements
what is the most severe type of stroke
total anterior circulation syndrome
what happens in TACS
anterior and middle cerebral arteries are involved
how do we define TACS (3)
- Contralateral hemiplegia or hemiparesis, AND
- Contralateral homonymous hemianopia, AND
- Higher cerebral dysfunction (e.g. aphasia, neglect)
what does PACS stand for
partial anterior circulation syndrome
what is PACS
anterior or middle cerebral artery is affected
how do we define PACS (2)
- 2 out of the 3 features present in a TACS OR
- Higher cerebral dysfunction alone e.g. dysphagia
what does POCS stand for
posterior circulation syndrome
what does TACS stand for
total anterior circulation syndrome
what does POCS involcve
vertebrobasilar arteries and associated branches supplying the cerebellum, brainstem and occipital lobe
how is POCS defined (5)
- Cerebellar dysfunction, OR
- Conjugate eye movement disorder, OR
- Bilateral motor/sensory deficit, OR
- Ipsilateral cranial nerve palsy with contralateral motor/sensory deficit, OR
- Cortical blindness/isolated hemianopia
what are lacunar infarcts
small infarcts around deeper parts of the brain caused by occlusion of a single deep penetrating artery
which type of stroke has the best prognosis
lacunar infarcts
what are the 4 types of lacunar infarcts
pure motor
pure sensory
sensorimotor
ataxic hemiparesis
what causes a pure motor stroke
infarction of the internal capsule, corona radiata or pons
presentation of a pure motor stroke
contralateral hemiparesis without sensory, visual or language impairment
what causes a pure sensory stroke
infarct in the thalamus
presentation of a pure sensory stroke
sensory deficits affecting one side of the body without motor deficits
which part of the brain is often affected in a sensorimotor stroke
thalamocapsular region
presentation of a sensorimotor stroke
combined motor and sensory deficits on the same side
what usually causes ataxic hemiparesis
infarct in the pons or internal capsule
how does ataxic hemiparesis present
weakness and incoordination on the same side
what should not be present in a lacunar infarct
visual field defects, higher cerebral dysfunction or brainstem dysfunction
what is a common general obs identified in patients following a stroke
elevated BP
what scoring tool is used to recognise a stroke in the ER and what score is clinically significant
ROSIER
score >0 stroke is likely
how do we differentiate between types of stroke
CT head
what investigation should also be performed is thrombectomy is indicated
CT contrast angiography
what is primary management of ischaemic stroke
thrombolysis or thrombectomy
what is used to perform thrombolysis in stroke
alteplase
what is the mechanism of action of alteplase
tissue plasminogen activator
when is thrombolysis indicated for managing stroke
patients presenting within 4.5 hours with no contraindications
what are some contraindications for thrombolysis
previous haemorrhage or infarct, high BP, anticoags, surgery/head trauma, pregnancy
when is mechanical thrombectomy indicated in stroke patients
with anterior circulation strokes within 6 hrs
posterior circulation strokes within 12 hours
what is used in patients with ischaemic stroke if hyper-acute management cannot be offered
aspirin 300mg once daily for 2 weeks
what is started for patients 24 hours after hyper-acute management of ischaemic stroke (and on what condition)
aspirin - given there has been a repeat CT to exclude new haemorrhage
when might decompressive craniectomy be considered in the management of stroke
within 48 hours in MCA strokes causing infarction of >50% of the teritory
what is used as secondary prevention in ischaemic stroke
antiplatelet therapy - clopidogrel
name some other secondary prevention interventions used for patients following a stroke
antihypertensives
statins
diabetic control
smoking cessation
what is a TIA
transient ischaemic attack
how long do symptoms last in a TIA
<24 hours
what is the usual cause of a TIA
microemboli
what is often the first clinical sign of internal carotid artery stenosis
amaurosis fugax
what is amaurosis fugax
transient loss of vision in one eye
what is the general presentation of a TIA
sudden loss of function, usually lasting for minutes, with complete recovery and no evidence of infarction on imaging
what investigations are used in a suspected TIA
carotid duplex ultrasound
ECG
blood tests
management of a TIA
antiplatelet therapy - aspirin
surgery and stenting for carotid stenosis
