Stroke- types and medications Flashcards
brain supplied from
2 vertebral arteries- go through vertebra in cervical spine- TP in foramina and joint in front of brainstem=basilar artery, 2 internal carotid arteries- come up front of neck, and divide to form anterior and middle cerebral arteries
2 ACA’s join anteriorly via the anterior communicating artery- front section of circle of Willis
circle of willis
vertebral artery come up the back and form basilar arteries (supplies back of brain- cerebellum- brain stem), this then forms circle with 2 internal carotid arteries, this then divides into anterior/ middle/ posterior cerebral arteries
what does upper brainstem and basilar arteries divide into
2 posterior cerebral arteries- connect to back of circle of Willis by 2 small posterior communicating arteries
circle of Willis
occlusion of one internal carotid does not necessarily result in stroke- have another one, brain may be protected from bilateral carotid through basilar supply, end arteries (no connections)- ACA, MCA, PCA
which parts of the brain are supplied by each artery- middle cerebral artery
most of the outer surface, sensorimotor cortex- parietal lobe, basal ganglia- movement memories store dhere, internal capsule- where sensory and motor pathways go through, broca’s area
which parts of the brain are supplied by each artery- anterior and posterior cerebral artery
anterior- frontal lobe, medial part of sensorimotor cortex, posterior- occipital lobe, medial aspect of temporal lobe, thalamus
which parts of the brain are supplied by each artery- basilar artery
all of the brainstem- vital control centre, cerebellum, nuclei of cranial nerves
what is a stroke
this is a rapidly developing clinical signs and symptoms of focal and at times global loss of vertebral function lasting more than 24 hours or that lead to death, no apparent cause other than vascular
what is a TIA
transient ischemic attack- mini stroke- a sign that part of the brain is not getting enough blood, and there is a risk of more serious stroke in the future. it used to be considered symptoms lasting less than 24 hours, but now is 2 hours
types of strokes
classified according to underlying pathology- hemorrhagic and ischemic- classified according to site and extent of lesion
Bamford classification of ischaemic stroke
based on the area of brain involved and extent of lesion: TACS- total anterior circulation stroke, PACS- partial anterior circulation stroke, POCS- posterior circulation stroke, LACS- lacunar stroke (deep penetrating arteries)
Anterior circulation stroke and PACS- diagnosis
all 3- unilateral weakness (and/or sensory deficit) of face/ arm / leg
homonymous hemianopia
higher cerebral dysfunction
PACS- 2 of the following
POCS- diagnosis
one of- cerebellar or brainstem syndromes, loss of consciousness, isolated homonymous hemianopia
LACS- diagnosis
one of- unilateral weakness (and/or sensory deficit) of face and arm, arm and leg, or all 3
pure motor/sensory stroke, ataxic hemiparesis
ischaemic stroke
80% stroke due to occlusion- atheroma of cerebral arteries, blood clot in the brain or neck- thrombosis, blot clot from somewhere else that has moved and now blocks a blood vessel in the brain/neck= embolism
where are ischaemic strokes common
MCA>PCA>ACA, brain stem stroke less common but more serious
embolic stroke
completed stroke- sudden onset, TIA- repeated small emboli, no infraction occurs
thrombotic stroke
usually develops overnight- completed stroke
developing stroke- develop over several days, TIA- sudden- full recovery- 20% risk of full CVA within first 4 weeks
medical management of emboli/ thrombus
treat as medical emergency, MRI/CT scan within 5 hours, ischemic stroke- aspirin, anticoagulants, thrombolysis, TIA- aspirin, prevention work
medical management of emboli/ thrombus- other tests and surgery
blood tests, angiography, echocardiology
surgery- thrombectomy- remove fatty deposits, carotid endarterectomy- scrape fatty deposits
haemorrhagic strokes
intracerebral haemorrhage, subarachnoid haemorrhage (in arachnoid space- under), subdural hemorrhage (under dura matter), extradural haemorrhage (outside dura matter)
what is pia matter
covers the brain- next layer is the arachnoid layer (all capillaries in this area)- final layer- very robust and strong
subarachnoid haemorrhage
bleeding into subarachnoid space, due to rupture of congenital aneurysm, arteriovenous malformation (AVM) or trauma, associated with sudden intense headache/ vomiting/ neck stiffness and loss of consciousness
approx 10% die within 1st 2 hours 40% die within 2 weeks
extradural haemorrhage
bleeding into extradural space, caused by severe trauma and tearing of meningeal artery
medical management of haemorrhagic stroke
treat as medical emergency, MRI/CT scan, SAH- surgery or endoplasmic procedure, SDH/EDH/ICH- treat hypertension, other tests- blood tests, angiography, echocardiology, other medication- osmotic agents
bleed vs blockage- loss of consciousness, headache, nausea and vomiting
bleed- at presentation, the rule, frequent
blockage- unusual, occasional, posterior fossa
bleed vs blockage- coma, stuttering course, previous TIA’s
bleed- frequent, rarely, very unusual, blockage- late if at all, frequent, sometimes
