Chapter 96 - Unusual carotid artery conditions Flashcards
Nonatherosclerotic causes of cerebrovascular symptoms
1) carotid kinking/coiling
2) carotid aneurysms
3) dissections
4) FMD
5) radiation arteritis
6) GCA
7) takayasu arteritis
8) cardiac embolization
9) carotid sinus syndrome
10) moyamoya
Carotid sinus syndrome
1) hypersensitivity of carotid sinus to daily life
2) syncopal symptoms 35% lifetime risk
3) reflex brady and hypotension
Carotid sinus hypersensitivity
bradycardia or hypotension to carotid sinus massage
3 types of carotid sinus hypersensitivity
1) carotid sinus hyperactivity: ventricular pause > 3 sec
2) asodepressor carotid sinus hyperactivity: BP drop > 50 mmHg without bradycardia
3) mixed
Treatment for 1 = pacing
treatment for 2 = drugs
Afferent signal from carotid sinus via this nerve
Glossopharyngeal and vagus
Efferent signal to heart and blood vessels for BP control
vagus
Symptoms of carotid sinus hypersensitivity
presyncope/syncope
1) abnormal sensorium
2) vision changes
3) parethesia
4) paresis
5) cognitive dysfunction
provocative maneuver = head turning, age, tight neck collars
Carotid sinus massage
1) upright position
2) monitor ECG adn BP
3) 5-10 s massage of one side
4) anterior margin of SCM at cricoid cartilage level
5) repeat on opposite side
6) if response then atropine then continue to determine extent needed
Treatment for carotid sinus hypersensitivity
1) fluid + salt intake, avoid physical maneuvers
2) midodrine
3) SSRI
4) fludrocortisone
5) norepinephrine
6) PM (DDD)
7) surgery: adventitial stripping
Moyamoya first described
Suzuki and Takaku 1969
Define moyamoya disease (MMD)
chronic, idiopathic, progressive cerebrovascular disease with ICA stenosis and occlusion
1) abnormal vascular network at brain base
2) more in east asian
3) prevalence 0.35-2.3/100000
4) 5-15 yo and 30-40 yo bimodal
5) more in females
symptom of MMD in children
1) paroxysmal hemiplegia
2) paresthesia
3) facial paralysis
4) paroxysmal headache
5) fine involuntary movement of extremity
6) progressive mental impairment
Symptom of MMD in adults
1) sudden disturbance of consciousness
2) intracranial hemorrhage
3) bleeding into ventricle
4) subarachnoid hemorrhage
Autoimmune disease associated with MMD
Graves
Familial form of MMD consist of this percentage
10%
autosomal dominant inheritance with low penetrance
Etiology of sporadic MMD
1) infectious
2) autoimmune
3) protein abnormality
4) genetic
Genetic loci of MMD
1) 3p24-26
2) 8q23
3) 6q25
4) 17q25 (RNF213)
5) 10q23.31
Pathophysiology of MMD
1) fibrocellular thickening of intima
2) SMC accumulation
3) stenosis to occlusion
4) HIF-1, VEGF, TGFB, hepatocyte GF, MMP expression
5) collateralization with Moyamoya vessels
Moyamoya vessels
1) thin media
2) fibrin deposit in vessel wall
3) fragmented elastic laminae
4) increase tendency to form microaneurysms
Suzuki and Takaku grading of MMD
Stage 1: narrowing or carotid fork
Stage 2: Moyamoya vessels, dilation of intracerebral main artery, no collateral from ECA
Stage 3: moyamoya affect MCA and ACA
Stage 4: moyamoya minimized with occlusion of ICA to level of Pcom
Stage 5: main ICA disappear, even less moyamoya
Stage 6: moyamoya and ICA totally gone
Treatment of moyamoya
1) avoid hyperventilation/exercise
2) anti HTN, lipid, DM, smk, wt loss, stop OCP
3) surgery: direct superficial temporal to MCA
4) surgery indirect pial synangiosis (temporal artery secured onto pia)
not antiplatelet - high risk of bleed
ICA coiling definition
Elongation and redundancy resulting in S shaped curvature
not clinically relevant stenosis on its own
ICA kinking degree
Mild > 60 degrees
Moderate 30-60 degrees
Severe < 30 degrees
associated with neuro symptoms 4-20%
epidemiology of carotid kinking/coiling
incidence 24.6%
female 70.6%
> 60 years old
kinking 56%
tortuosity 38%
coiling 6%
Cause of coiling of carotid
Embryologically ICA from 3rd aortic arch and dorsal aorta
in embryo vessle naturally coiled
heart receds into thorax and therefore stretches this out
abnormal embryology causes this
Cause of kinking of carotid
more related to atherosclerosis
Treatment of kinking/coiling
1) antiplatelet
2) surgical transection and elongation
3) surgical transection and interpositional bypass
4) ICA to ECA reattachment
Intracranial arterial stenosis causes
1) primary atherosclerosis
2) emboli
3) dissection
4) vasculitis
5) CNS infection
6) radiation
7) sickle cell disease
8) moyamoya disease
Risk factors for intracranial arterial stenosis
1) HTN
2) smk
3) endothelial injury
4) increased vascular permeability
Stroke outcomes and neuroimaging of intracranial atherosclerosis SONIA trial
MRI and TCD good for screening (high npv)
poor for PPV
therefore need DSA
Warfarin and asa for symptomatic intracranial arterial stenosis (WASID) trial
1) 2005
2) double blind warfarin vs asa
3) no difference in stroke or death
Clopidogrel plus asa for infarction reduction (CLAIR) study
1) 2010
2) combination therapy better than ASA alone for microembolif ormation (RRR 42.4%)
Stenting vs aggressive medical therapy for intracranial arterial stenosis SAMMPRIS study
DAPT > ASA alone > ASA + stent
med therapy alone is the tx of choice
EC/IC bypass study
EC-IC bypass not helpful to prevent stroke in MCA disease compared to ASA
Concurrent carotid stenosis and intracranial aneurysm on life expectancy
Life expectancy 15-35 years
Age 45-70 years
aneurysm < 7 mm
go ahead and treat the carotid stenosis and ignore the aneurysm
Diagnosis of cerebral vasculitis
1) symptoms
2) CSF fluid analysis
3) MRI, CTA
4) biopsy
Vasculitides of cranial arteries
types
age and treatment
1) takayasu
2) wegener
3) temporal arteritis
40-60’s age
glucocorticoids
revascularization
Lacunar infarct first description
Dechambre 1838
Definition of lacunar infarct
1) noncortical infarct
2) single penetrating branch occlusion of larger cerebral arteries
3) diameter 0.2-15 mm
Lacunar infacts as percentage of all ischemic strokes
20%
most asymptomatic
Symptoms of lacunar infarct
1) motor hemiparesis
2) aphasia
3) dysarthria
4) change in LOC
5) mutism
6) sensorimotor dysfunction
Parts of the brain affected by lacunar infarcts
1) putamen
2) pallidum
3) pons
4) thalamus
5) internal capsule
6) corona radiate
7) caudate nucleus
limited collateral circulation
Pathophysiology of lacunar infarct
1) medial thickening from disease and occlusion
2) parent artery plaque penetrate occlusion
Treatment of lacunar infarct
1) tpa within 3 hours
2) treat other medical condition
3) carotid endarterectomy if there’s stenosis
Number needed to treat to prevent one stroke with CEA for lacunar infarct
83
higher than other ipsilateral infarcts
