title: Intracranial stenosis in cognitive impairment and dementia.
abstract: Intracranial stenosis is a common vascular lesion observed in Asian and other non-Caucasian stroke populations. However, its role in cognitive impairment and dementia has been under-studied. We, therefore, examined the association of intracranial stenosis with cognitive impairment, dementia and their subtypes in a memory clinic case-control study, where all subjects underwent detailed neuropsychological assessment and 3 T neuroimaging including three-dimensional time-of-flight magnetic resonance angiography. Intracranial stenosis was defined as ≥50% narrowing in any of the intracranial arteries. A total of 424 subjects were recruited of whom 97 were classified as no cognitive impairment, 107 as cognitive impairment no dementia, 70 vascular cognitive impairment no dementia, 121 Alzheimer's Disease, and 30 vascular dementia. Intracranial stenosis was associated with dementia (age/gender/education - adjusted odds ratios (OR): 4.73, 95% confidence interval (CI): 1.93-11.60) and vascular cognitive impairment no dementia (OR: 3.98, 95% CI: 1.59-9.93). These associations were independent of cardiovascular risk factors and MRI markers. However, the association with Alzheimer's Disease and vascular dementia became attenuated in the presence of white matter hyperintensities. Intracranial stenosis is associated with vascular cognitive impairment no dementia independent of MRI markers. In Alzheimer's Disease and vascular dementia, this association is mediated by cerebrovascular disease. Future studies focusing on perfusion and functional markers are needed to determine the pathophysiological mechanism(s) linking intracranial stenosis and cognition so as to identify treatment strategies.
authors.affiliation: 1 Memory Ageing and Cognition Centre (MACC), National University Health System, Singapore, Singapore.|2 Department of Pharmacology, National University of Singapore, Singapore, Singapore.
authors.forename: Saima
authors.initials: S
authors.lastname: Hilal
authors.affiliation: 1 Memory Ageing and Cognition Centre (MACC), National University Health System, Singapore, Singapore.|2 Department of Pharmacology, National University of Singapore, Singapore, Singapore.
authors.forename: Xin
authors.initials: X
authors.lastname: Xu
authors.affiliation: 3 Academic Medicine Research Institute, Duke-NUS Graduate Medical School, Singapore, Singapore.|4 Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: M Kamran
authors.initials: MK
authors.lastname: Ikram
authors.affiliation: 5 Departments of Radiology & Medical Informatics, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Henri
authors.initials: H
authors.lastname: Vrooman
authors.affiliation: 6 Raffles Neuroscience Centre, Raffles Hospital, Singapore, Singapore.
authors.forename: Narayanaswamy
authors.initials: N
authors.lastname: Venketasubramanian
authors.affiliation: 1 Memory Ageing and Cognition Centre (MACC), National University Health System, Singapore, Singapore.|2 Department of Pharmacology, National University of Singapore, Singapore, Singapore.
authors.forename: Christopher
authors.initials: C
authors.lastname: Chen
mesh_terms: D000368:Aged; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging; D016022:Case-Control Studies; D060825:Cognitive Dysfunction / Q000000981:diagnostic imaging / Q000473:pathology*; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging* / Q000473:pathology; D015140:Dementia, Vascular / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D059906:Neuroimaging / Q000379:methods*
keywords: Cognitive impairment; cerebrovascular diseases; dementia; intracranial stenosis; magnetic resonance angiography