Strokes Flashcards
risk factors for TIAs
Prior TIA or stroke Hypertension AF Diabetes History of Ischaemic heart disease Smoking
visual syndrome from TIA
amaurosis fugax - embolism of retinal artery, painless loss of vision in one eye, curtain coming down
clinical features of TIA
similar to stroke
cortical symptoms - facial or limb weakness
speech abnormalities - dysphagia or dysarthria
visual disturbance - visual field defect or amarousis fugax
cranial nerve involvement
memory disturbance
general investigations for TIAs
FBC, renal function, glucse, ESR, ECG
specific investigations for TIAs
MRI, carotid doppler
what does the ABCD2 score stand for
age, blood pressure, clinical features, duration, diabetes
how quickly should patients who score >4 in ABCD2 be seen
assessed within 24hrs
what is the medication management of TIAs
aspirin 300mg daily for 2 weeks, then 75mg of clopidogrel for life
what is the management of TIAs in those already on anti platelet therapy
dipyridamole
what are the indications for warfarin in TIA treatment?
if cause is a cardio-embolism and the risk factors (chronic non-valvular AF, metallic prosthetic cardiac valves and acute left ventricular wall motion impairment)
Definition of a stroke
rapidly developing clinical symptoms and/or signs of focal, and at times global, loss of brain function, with symptoms lasting more than 24 hours of leading to death with no apparent cause other than that of vascular origin
2 types of stroke
ischaemic and hemorrhagic
ischaemic stroke pathophysiologically can be classified into
primary vascular pathologies
cardiac pathologies
haematological pathologies
examples of primary vascular pathologies are
atherosclerosis, aortic arch atherosclerosis, arterial dissection, migraine or vasculitis
examples of cardiac pathologies
AF, MI, patent foramen ovale
examples of haematological pathologies
prothrombic hypercoagulable or hyperaggregable states
what is global hypoxic ischaemia
damage is when the systemic compromise to circulation cannot be compensated for by CNS auto-regulatory mechanisms – generalised reduction in blood flow
occurs in cardiac arrest, severe hypotension e.g. hypovolemic shock
Occurs when BP is below 50mmHg
Severe ischemia leads to pan-necrosis
what is focal hypoxic ischaemia
involves restriction of blood flow to a localised area of the brain)
typically due to vascular obstruction
What are watershed areas?
Watershed areas sensitive – zone between two arterial territories so furthest from heart and least well supplied
what are the sensitivities of different brain cell types
Neurons more sensitive than glial cells, and some neurons are more sensitive than others: Neocortex and hippocampus, Purkinje cells
what are the different types of thrombus ischaemic strokes and what is the thrombus made from
cardioembolic (fibrin)
atheroembolic (platelet)
which vessels are most commonly affected by thrombotic stroke?
branching points of the internal carotid and the middle cerebral artery
histological features at 0-12 hours
macroscopy - little visible
microscopy - little visible
histological features at 12-24 hours
macroscopy - pale soft and swollen with ill defined margin between injured and normal brain
microscopy - red neuron, oedema (cytotoxic and vasogenic) with generalised cell swelling
histological features at 24-48 hours
microscopy - increasing neutrophils, extravasation of red blood cells (haemorrhagic conversion) and activation of astrocytes ad microglial
histological features at 2-14 days
macroscopy - brain becomes gelatinous and friable. A reduction in the surrounding tissue oedema demarcates the lesion
Microscopy - microglia become predominant cell type, myelin breakdown. Reactive gliosis begins from as early as 1 week
histological features after several months
macroscopy - increasing liquification apparent. eventual formation of cavity lined by dark grey tissue
microscopy - ongoing phagocytosis brings increasing cavitation and surrouding gliotic scar formation
risk factors for ischaemic stroke (name 10)
older age, family history of stroke, history of ischaemic stroke, hypertension, smoking, diabetes mellitus, atrial fibrillation, comorbid cardiac conditions, carotid artery stenosis, sickle cell disease, dyslipidaemia, people with lower levels of education, African-American or Hispanic ancestry, poor diet and nutrition, physical inactivity, obesity, alcohol abuse, oestrogen-containing therapy, illicit drug use, migraine, hyperhomocysteinaemia, elevated lipoprotein(a), hypercoagulable states, elevated C-reactive protein, aortic arch plaques
criteria for a TAC
all three of:
Higher cerebral dysfunction (e.g. dysphasia).
Homonymous visual field defect
Ipsilateral motor and/or sensory deficit of at least two areas (out of face, arm and leg)
TACs affect which part of the circulation
entire anterior circulation supplying one side of the brain
criteria for a PAC
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)
PACs affect which part of the circulation
part of the anterior circulation supplying one side of the brain
criteria for a LAC
Affect 2 any two of face arm and leg
pure motor or pure sensory stroke or an ataxic hemiparesis
LACs affect which part of the circulation
occlusion of a single deep penetrating artery that arises directly from the constituents of the Circle of Willis, cerebellar arteries, and basilar artery
criteria for a POC
ipsilateral cranial nerve palsy with contralateral motor and/or sensory deficit
Bilateral motor and/or sensory deficit
Cerebellar dysfunction
Isolated homonymous visual field defect
POCs affect which part of the circulation
affecting the posteriorcirculation supplying one side of the brain.
