Cognitive impairment in asymptomatic carotid artery stenosis is associated with abnormal segments in the Circle of Willis

S K Desikan; B Brahmbhatt; J Patel; A Kankaria; J Anagnostakos; M Dux; K Beach; V L Gray; T McDonald; C Crone; S Sikdar; J D Sorkin; B K Lal

doi:10.1016/j.jvs.2024.04.059

Cognitive impairment in asymptomatic carotid artery stenosis is associated with abnormal segments in the Circle of Willis

J Vasc Surg. 2024 May 4:S0741-5214(24)01085-1. doi: 10.1016/j.jvs.2024.04.059. Online ahead of print.

Authors

S K Desikan¹, B Brahmbhatt², J Patel³, A Kankaria¹, J Anagnostakos¹, M Dux⁴, K Beach⁵, V L Gray⁶, T McDonald¹, C Crone¹, S Sikdar², J D Sorkin⁷, B K Lal⁸

Affiliations

¹ Division of Vascular Surgery, University of Maryland School of Medicine, Baltimore, MD, USA; Vascular Service, Veterans Affairs Medical Center, Baltimore, MD, USA.
² Department of Bioengineering, George Mason University, Fairfax, VA, USA.
³ Radiology Service, Veterans Affairs Medical Center, Baltimore, MD, USA.
⁴ Neuropsychology Section, Veterans Affairs Medical Center, Baltimore, MD, USA.
⁵ D. Eugene Strandness Vascular Laboratory, Department of Surgery, University of Washington, Seattle, WA, USA.
⁶ Department of Physical Therapy and Rehabilitation Science, University of Maryland, Baltimore, MD, USA.
⁷ Baltimore VA Geriatric Research, Education and Clinical Center, Baltimore, MD, USA; Department of Medicine, Division of Gerontology and Palliative Care, University of Maryland School of Medicine, Baltimore, MD, USA.
⁸ Division of Vascular Surgery, University of Maryland School of Medicine, Baltimore, MD, USA; Vascular Service, Veterans Affairs Medical Center, Baltimore, MD, USA. Electronic address: blal@som.umaryland.edu.

PMID: 38710420
DOI: 10.1016/j.jvs.2024.04.059

Abstract

Objective: Our group has previously demonstrated that patients with asymptomatic carotid artery stenosis (ACAS) demonstrate cognitive impairment. One proposed mechanism for cognitive impairment in patients with ACAS is cerebral hypoperfusion due to flow-restriction. We tested whether the combination of a high-grade carotid stenosis and inadequate cross-collateralization in the Circle of Willis (CoW) resulted in worsened cognitive impairment.

Methods: Twenty-four patients with high-grade (≥70% diameter-reducing) ACAS underwent carotid duplex ultrasound, cognitive assessment, and 3D time-of-flight magnetic resonance angiography (MRA). The cognitive battery consisted of nine neuropsychological tests assessing four cognitive domains: learning and recall, attention and working memory, motor and processing speed, and executive function. Raw cognitive scores were converted into standardized T-scores. A structured interpretation of the MRA images was performed with each segment of the CoW categorized as being either normal or abnormal. Abnormal segments of the CoW were defined as segments characterized as narrowed or occluded due to congenital aplasia or hypoplasia, or acquired atherosclerotic stenosis or occlusion. Linear regression was used to estimate the association between the number of abnormal segments in the CoW, and individual cognitive domain scores. Significance was set to p<0.05.

Results: The mean age of the patients was 66.1 + 9.6 (mean + SD) years and 79.2% (n=19) were male. A significant negative association was found between the number of abnormal segments in the CoW and cognitive scores in the learning and recall (β = -6.5, p = 0.01), and attention and working memory (β = -7.0, p = 0.02) domains. There was a trend suggesting a negative association in the motor and processing speed (β = -2.4, p = 0.35) and executive function (β = -4.5, p = 0.06) domains that did not reach significance.

Conclusion: In patients with high-grade ACAS, the concomitant presence of increasing occlusive disease in the CoW correlates with worse cognitive function. This association was significant in the learning and recall and attention and working memory domains. While motor and processing speed and executive function also declined numerically with increasing abnormal segments in the CoW, the relationship was not significant. Since flow restriction at a carotid stenosis compounded by inadequate collateral compensation across a diseased CoW worsens cerebral perfusion, our findings support the hypothesis that cerebral hypoperfusion underlies the observed cognitive impairment in patients with ACAS.