stroke Flashcards
stroke defination
Acute onset of
Focal neurological symptoms/signs due to
Interruption of blood supply
lasts longer than 24 hours or leads to death.
TIA
same thing just <24h
RF
oral contraceptive pill
undiagnosed AF
main causes
ischaemic most common- large artery disease, cardioembolic, lacunar
haemorrhagic- hypertension, cerebral amyloid angiopathy
lacunar
Caused by occlusion of a single deep penetrating artery. Affect 2 any two of face arm and leg
basal ganglia, thalamus, white matter) and in the brain stem.
best prognosis
cerebral amyloid angiopathy
accumulation of amyloid beta-peptide within the leptomeninges and small/medium-sized cerebral blood vessels.
leptomeninges- arachnoid and pia
Penumbra
area of brain with reduced cerebral blood flow, but also getting supply of O2 and glucose from collateral arteries.
At risk of progressing to infarction but is still salvageable if reperfused
Ischaemic Core
area of brain which have developed necrosis. Cerebral blood flow < 20%.q
Ischaemic Cascade
Switch from Aerobic to anaerobic metabolism-
Accumulation of lactic acid
Na/K channel dysregulation – cytotoxic oedema
Na/Ca channel dysregulation –increase Ca within neuron:
Excitotoxicity
Degradative enzymes
Formation of radicals
Mitochondrial apoptotic factors
vasogenic oedema
starts 4-6 hours after ischaemia
Basement membrane becomes leaky and things comes out so oedema, mass effect, pushes brain oppostie way and down which is fatal
post stroke there is
inflammation
TOAST 1
Large Artery Atherosclerosis
Atherothrombosis or thromboembolism
TOAST 2
Cardioembolic- any cardio cause e.g. atrial myxoma/tumur of atria, endocarditis
TOAST 3
Small artery disease
lacunar stroke
Caused by lipohyalinosis (thickened vessel wall with lumina narrowing)- hypertension/diabetes
TOAST 4
other
vasculitis
genetic microangiopathy
SUSAC syndrome (retino-cochlea-cerebral vasculopathy)
hypercoaguble states/antiphospholipid syndrome
COVID/HIV
recreational drugs
pregnancy
TOAST 5
unknown
Anterior cerebral artery/Middle cerebral artery symptoms
Hemiparesis- weakness/inability to move one side
Hemisensory loss
Hemianopia (affects optic tract)
Dysphasia (left MCA)- speech
Sensory/visual inattention/neglect (right MCA)
Lacunar syndromes (perforating arteries) symptoms
anterior
Pure motor stroke
Pure sensory stroke
Sensorimotor stroke
Clumsy handdysarthria(slight weakness and clumsiness of the hand with slurred speech)
Ataxic hemiparesis (ataxia and usually mild hemiparesis affecting the same side)
Posterior circulation supplies
Comprised of 2 vertebral arteries and basilar artery – become posterior cerebral artery
Supply occipital cortex – hemianopia
Supply brainstem and cerebellum-
Posterior circulation symptoms
Supply brainstem and cerebellum-
Hemiparesis/hemisensory loss (involvement of ascending and descending tracts)
Ataxia- balance, coordiantion
Dysarthria- speech due to muscle weakness
Due to cranial nerve nuclei involvement – vertigo, diplopia, facial nerve palsy, tongue palsy, dysphagia
Bilateral symptoms – basilar artery syndrome
Total Anterior Circulation Syndrome (TACS)
Hemiplegia involving at least two of face, arm and leg +/- hemisensory loss Homonymous Hemianopia
Cortical signs (dysphasia, neglect etc)
worst type- bad prognosis
Partial Anterior Circulation Syndrome (PACS)
2 out of 3 features present in a TACS or;
Isolated Cortical Dysfunction such as dysphasia or;
Pure motor/sensory signs less severe than in lacunar syndromes (eg monoparesis).
half patients recover
Posterior Circulation Syndrome (POCS)
Cranial nerve palsies
Bilateral motor and/or sensory deficits
Conjugate eye movement disorders Isolated homonymous hemianopia Cortical blindness
Cerebellar deficits without ipsilateral motor/sensory signs
good prognosis
