D: Vascular 4 Stroke/TIA/Cerebrovascular - Week 8 Flashcards
Define stroke
sudden, focal interruption of cerebral blood flow that causes neurologic deficit
What percentage of strokes are ischaemic? And what do these types of strokes typically result from?
80%. Typically result from thrombosis or embolus
What percentage of strokes are haemorrhagic? What do these types of strokes result from?
20%. Resulting from vascular rupture (e.g. subarachnoid or intra-cerebral haem)
What proportion of stroke/CVA patients recover, die, or have a residual handicap?
1/3rd for each
Define Transient Ischaemic Attack (TIA)
stroke symptoms typically lasting less than 1 hour (must be less than 24 hours) and often leaves no or minimal damage
List 8 symptoms of stroke. Do they occur suddenly?
Numbness
Parasthesia (tingling)
Weakness
Contralateral limb/face paralysis
Aphasia (speech problems)
Confusion
Visual disturbances (one or both eyes) incl dizzy
Headache
Yeah, they do
What symptoms does an anterior circulation stroke typically produce?
unilateral symptoms
What symptoms does a posterior circulation stroke typically produce?
unilateral or bilateral deficits (and more likely to affect consciousness, compared to anterior)
What 3 features of a stroke are the resultant visual signs and symptoms dependent on?
Location/blood vessels affected
Type of stroke
Effect on cranial nerves
List 8 predisposing risk factors for stroke
Age
Atherosclerosis
Uncontrolled hypertension
Diabetes
Smoking
High HDL/LDL levels
Sedentary life style
Blood viscosity disorders
(also note: migraine and carotid artery stenosis)
What percentage of stroke patients are over 50 years old?
92%
What percentage of strokes are caused by internal carotid artery occlusion?
20%
What 4 prodromes may often occur preceding a stroke caused by internal carotid artery occlusion?
TIA
Amaurosis (partial/total blindness)
Speech
Tingling/sensations
What percentage of patients with internal carotid artery are asymptomatic at autopsy?
6.5%
What types of temporary neurological dysfunctions can occur with TIAs?
somatosensory
motor
vision (amaurosis fugax = painless temporary loss of vision in one or both eyes)
What 3 things are TIAs characterised by?
Abrupt onset
Short duration (generally 1-2 mins, 5 mins common, but up to 24 hours)
Complete recovery (with no residual deficit, generally)
How does TIA influence the risk of stroke? How long does this apply?
Significantly increases it. In fact, major stroke events commonly occur within the first week after the first TIA.
Risk increases for the next 2 years
Define carotid stenosis
Narrowing of the blood vessels in the neck that carry blood from the heart to the brain. Can lead to a TIA.
In TIA, in which eye would you expect to experience loss of vision?
Ipsilateral to the existing carotid stenosis
In TIA, on what side of your body would you expect motor/sensory defects?
The contralateral side to the existing carotid stenosis
What should you ask in history for a patient suspected of having TIAs?
“Do you ever have visual blackouts lasting for a few minutes”
What should you ask in history for a patient suspected of having vertebro-basilar TIA?
“Any falls or extreme faints?”
List 5 unilateral signs suggestive of carotid insufficiency
Venous stasis retinopathy (VSR)
Ocular ischaemic syndrome
Unilateral pain
Cataract - asymmetric
Dilated conjunctival/scleral vessels
List 3 atherosclerotic signs suggestive of carotid insufficiency
BRAO (old or recent)
Hollenhost plaque (cholesterol)
Fisher plug (fibrin)
What is Carotid Artery Auscultation?
It’s where you listen at the neck with a stethoscope at the carotid artery to hear the sound it makes
What does carotid artery auscultation test for?
narrowing at CC/ICA bifurcation
(ICA = internal carotid artery. CC = common carotid)
During carotid artery auscultation: What is a normal sound?
Heart sound (lub-dub)
During carotid artery auscultation: What is an abnormal sound? What does this sound indicate?
BRUIT: is a blowing/whooshing sound that indicates significant narrowing of the vessel lumen
What does it mean when you hear a louder BRUIT below the CC/ICA bifurcation during carotid artery auscultation?
Suggests a heart anomaly
What if you hear no sound during carotid artery auscultation? (2)
Either:
Not correctly positioned on artery (not on artery at all)
Artery completely blocked
What does a carotid ultrasound indicate when testing a patient for carotid insufficiency?
indicates degree of stenosis
What does ophthalmodymanometry measure?
ophthalmic artery pressure
What is a positive result in Ophthalmodymanometry?
20% difference between eyes
What 2 treatment options are there for carotid insufficiency?
Anticoagulant therapy (e.g. aspirin)
Surgery - carotid endarterectomy
Name 1 benefit and 1 downside of carotid endarterectomy
Advantage: reduces risk of stroke
Disadvantage: but there is a risk of inducing a stroke during the actual operation
For what type of patient demographic is carotid endarterectomy mainly indicated for?
younger patients in good health
