Compensatory intracranial arterial dilatation in extracranial carotid atherosclerosis: the Northern Manhattan study.
BACKGROUND
There is a scarcity of data supporting the association between atherosclerosis and dolichoectasia in unbiased samples.


OBJECTIVE
To test the hypothesis that the association between dolichoectasia and extracranial carotid atherosclerosis depends on the degree of collateral circulation.


METHODS
The Northern Manhattan Study magnetic resonance imaging substudy consists of 1290 participants who remained stroke-free at the time of magnetic resonance imaging. Arterial diameters were collected in all participants with available magnetic resonance angiography. Dolichoectasia was defined as a head-size adjusted diameter >2 standard deviation for each artery. Carotid Doppler was used to evaluate for carotid atherosclerosis (carotid plaque, maximum plaque thickness and carotid intima media thickness).


RESULTS
We included 994 participants with available Doppler and magnetic resonance angiography data (mean age 63 years, 60% female). Any dolichoectasia was reported in 16% of participants, 54% had at least one carotid plaque and the mean carotid intima media thickness was 0·92 ± 0·09 mm. After adjusting for demographic and clinical characteristics, there was no association between markers of carotid atherosclerosis and dolichoectasia. However, stratifying by collaterals, it was observed that dolichoectasia was more likely in the anterior and posterior circulations when collaterals were available among participants with carotid atherosclerosis. These associations were confirmed by noting an increment in arterial diameters in the corresponding arteries ipsilateral and contralateral to each carotid as well as in the posterior circulation.


CONCLUSIONS
We did not find an association of extracranial carotid atherosclerosis with dolichoectasia. However, we found that dolichoectasia is more frequent when intracranial collaterals are available suggesting a compensatory process that needs further investigation.
Department of Neurology, Columbia University, New York, NY, USA.
Jose
J
Gutierrez
Department of Neurology, Columbia University, New York, NY, USA.|Department of Epidemiology, Columbia University, New York, NY, USA.
Mitchell S V
MS
Elkind
Department of Neurology, JM Ramos Mejia hospital, Buenos Aires, Argentina.
Maia
M
Gomez-Schneider
Department of Epidemiology, Columbia University, New York, NY, USA.
Janet T
JT
DeRosa
Division of Biostatistics, Columbia University, New York, NY, USA.
Ken
K
Cheung
Department of Radiology, University of Miami Miller School of Medicine, Miami, Florida, USA.
Ahmet
A
Bagci
Department of Radiology, University of Miami Miller School of Medicine, Miami, Florida, USA.
Noam
N
Alperin
Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, USA.
Ralph L
RL
Sacco
Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, USA.
Clinton B
CB
Wright
Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, USA.
Tatjana
T
Rundek
D000368:Aged; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology*; D059168:Carotid Intima-Media Thickness; D002533:Cerebral Angiography; D002941:Circle of Willis / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D020765:Intracranial Arterial Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged
Circle of Willis; atherosclerosis; carotid ultrasound; dolichoectasia; magnetic resonance imaging