Stroke Flashcards
What two paired arteries are responsible for blood supply to the brain
Vertebral and Internal Cartoid
Where does internal carotid arise from
bifurcation of the left and right common carotid arteries (C4)
What is the path of the ICA
Moves within cartoid sheath -> enter brain via carotid canal in temporal bone -> pass anteriorly through the cavernous sinus
What does the ICA give rise to
Opthalmic artery
Posterior communicating artery
Anterior cerebral artery
What does the opathalmic artery supply
Structures of orbit
What does the posterior communicating artery supply
Acts as an anastamotic ‘connecting vessel’ in the Circle of Willis
What does the anterior cerebral artery supply
Part of the cerebellum
What is the path of the vertebral arteries
Arise from subclavian -> ascend through posterior neck in foramen transversarium -> enter cranial cavity through foramen magnum -> covnerge to form basilar artery
What do the vertebral arteries give off
Meningeal branch
Anterior and posterior spinal arteries
Posterior inferior cerebellar artery
What does the meningeal branch supply
Falx cerebelli (sheet of dura matter)
What do the anterior and posterior spinal arteries supply
Spinal cord
What does the posterior inferior cerebellar artery supply
Cerebellum
What are the 3 main constituents of the circle of willis
Anterior cerebral artery - terminal branch of interal carotid
Internal carotid artery - proximal to the origin of the middle cerebral arteries
Posterior cerebral artery - terminal branch of vertebral
What does the anterior communicating artery do
Connects two ACAs
What does the PCA do
Branch of internal carotid, connects the ICA to the posterior cerebral artery
What is a stroke
focal neurological deficit of vascular origin lasting more than 24 hours or leading to death
Disease of the blood vessels
What are the causes of intracerebral haemorrhage
Anatomic: small vessel disease, amyloid angiopathy, AVMs (abnormal connection between arterial and venous system)
Haemodynamic: hypertension
Haemostatic factors: anticoagulants, anti-platelets, thrombolytic
Other: recreation drugs, vasculitis
What is white on a brain scan
thrombus, bone, haemorrhage, clot
What are the causes of ischaemic stroke
cardiac, large vessel atherosclerosis, small vessel disease
Low flow - thrombotic occlusion or embolism
AF can cause stasis
Carotid artery atherosclerosis causes 30%
What are the signs of ACA infarcation
Contralateral hemiparesis - leg more than arm/face
Cortical signs: dysphasia, emotional changes
What are the signs of MCA infarction
Contralateral hemiparesis Contralateral hemi sensory loss Cortical: Contralateral hemianopia Contralateral hemi neglect Dysphasia (left MCA)
What are the signs of PCA infarcation
Contralateral hemianopia
Contralateral hemi neglect
What are the signs of vertebrobasilar territory lesion
Nausea and vomiting (sits in medulla) Diplopia (CN III, III, VI sits in the midbrain of the pons) Vertigo Ataxia Hemi/quadriplegia Visual filed defect Coma
What causes Lacunar stroke
Small vessel disease from MCA affect sub-cortical structures: internal capsule and basal ganglia (thalamus, globus pallidus, substantia nigra)
What are the signs of Lacunar stroke
Pure hemiparesis Pure hemi sensory loss Sensorimotor stroke Ataxic hemiparesis No cortical features Better prognosis than large vessel strokes affecting cortex
What is TIA
Acute loss of coal cerebral or monocular function (symptoms < 24 hours)
Due to inadequate cerebral/ocular blood supply
Result of arterial thrombosis or embolism
Clinical diagnosis without specific diagnostic test
What are the non-focal symptoms of TIA
faintness, dizziness, light headedness, confusion, mental disorientation
What causes focal transient neurological attacks
focal cerebral ischaemia, migraine aura, partial epilepsy, Labyrinthine disturbances (Meniere’s disease, BPPV, Benign recurrent vertigo, Labyrinthitis/vestibularneuronitis)
What is migrane with aura
Positive phenomena 5-20 minutes
Visual symptoms may be homonymous, unilateral or central
Flashes of light, zig zag lines, scintillations, fortification spetra build up or expand
Paraesthesia or heaviness in one or other limbs
Spreads in minutes hand to elbow then face into tongue
What is transient global amnesia
Characteristics clinical syndrome
Middle-aged or elderly
Sudden disorder of memory
For a period pt has both anterograde and retrograde amnesia
