Una Clancy

Background and ObjectivesCross-sectional studies suggest that retinal microvascular abnormalities measured by optical coherence tomography angiography (OCTA) are associated with cerebral small vess...

Background and ObjectivesRecent small subcortical infarcts (RSSI) are common, but little is known about their tissue fates and relevance for clinical outcomes. We assessed predictors for long-term ...

BACKGROUND: The Fazekas score is widely used to grade white matter hyperintensities (WMHs) in cerebral small vessel disease, yet the equivalent volume of each grade is unclear. We quantified the correspondence between Fazekas scores and WMH volume, normalized ratios, and derived conversion equations across populations. METHODS: We analyzed 1220 participants from 4 mostly United Kingdom–based cohorts representing different cerebral small vessel disease severities: community-dwelling (LBC1936 [Lothian Birth Cohort 1936]), stroke (MSS2 [Mild Stroke Study 2] and MSS3 [Mild Stroke Study 3]), and a cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy-enriched cohort (INVESTIGATE [Imaging Neuro-Vascular, Endothelial and Structural Integrity in Preparation to Treat Small Vessel Diseases]). WMH burden was quantified as absolute WMH volume and as normalized ratios: WMH volume as a percentage of brain volume and WMH volume as a percentage of intracranial volume. Transition zones were defined as the overlap of WMH volume interquartile ranges between adjacent Fazekas scores. Linear, exponential (nonlinear least squares), and log-linear (ln WMH≈Fazekas score and zeros excluded) models were fitted; model fit was assessed using mean squared error, (pseudo-)R ² , and Vuong tests. Periventricular-versus-deep WMH patterns within each total Fazekas score were compared using the Kruskal-Wallis test. RESULTS: The pooled cohort had a mean age of 69.4±8.9 years; 700 of 1227 records (57.1%) were male. WMH burden increased monotonically with a Fazekas score in all cohorts. Adjacent-grade separation was strongest in LBC1936 (all P ≤0.002) but weaker at lower grades in MSS2, MSS3, and INVESTIGATE. The widest transition zones occurred between Fazekas grades of 3 to 4 and 4 to 5, whereas a clear WMH volume gap separated grades 5 and 6. Exponential models generally fit better than linear models, with lower mean squared error and supportive Vuong tests in most cohorts. Log-linear sensitivity analyses showed similar fitted trajectories after back-transformation. WMH burden did not differ consistently by periventricular-versus-deep distribution within Fazekas grades. CONCLUSIONS: WMH burden followed an exponential trajectory across Fazekas scores, with population-dependent progression. The resulting conversion equations enabled bidirectional translation between visual Fazekas score and quantitative WMH volume, facilitating cross-study comparison, large-scale epidemiology, and might facilitate clinical decision-making in cerebral small vessel disease.

BACKGROUND: Stenosis and dolichoectasia of cranial arteries likely reflect distinct mechanisms. Their contributions to lacunar stroke and cerebral small-vessel disease (cSVD) remain contentious. We investigated the associations of large-artery stenosis (LAS) and arterial widening with stroke subtype, cSVD markers, incident infarcts, and clinical outcomes. METHODS: We prospectively recruited patients with lacunar or mild nonlacunar stroke, with demographic, stroke-related, cognitive, functional, and magnetic resonance imaging (index and incident infarcts, cSVD markers) assessments at baseline and 1 year. LAS was defined as ≥50% intracranial or cervical artery stenosis; basilar artery dolichoectasia was defined by basilar artery diameter, bifurcation height, and lateral displacement; and intracranial carotid and middle cerebral artery diameters were also measured. Associations were estimated from multivariable logistic, linear, and proportional odds regression models adjusted for age, sex, and vascular risk factors. We further conducted a systematic literature review to synthesize evidence on relationships between large-artery pathology and cSVD. RESULTS: Among 229 patients (mean age, 65.9±11.1 years; 131 [57.2%] lacunar stroke), LAS and basilar artery dolichoectasia were present in 20.5% and 15.7%, respectively. After adjustment, LAS (odds ratio, 0.49 [95% CI, 0.23–0.99]) and the presence of any embolic source were associated with lower odds of lacunar versus non-lacunar stroke, and not with cSVD markers or incident infarcts. In contrast, basilar artery dolichoectasia was strongly associated with lacunar stroke (odds ratio, 4.67 [95% CI, 1.87–13.14]), higher cSVD scores (ordinal analysis; odds ratio, 2.57 [95% CI, 1.28–5.25]), incident infarcts (75% subcortical; odds ratio, 2.29 [95% CI, 1.01–5.14]), and greater progression of white matter hyperintensities over 1 year (β, 0.15 [95% CI, 0.01–0.29] per log ₁₀ -transformed volume). Similar associations were observed for wider intracranial arteries. The systematic review supported these findings. CONCLUSIONS: cSVD, including lacunar stroke, was unrelated to LAS but strongly associated with dolichoectasia and wider arteries. These findings support a nonatheromatous, intrinsic microvascular pathology, particularly segmental arteriolar disorganization, as the principal mechanism of lacunar stroke and cSVD. Mechanism-specific diagnostic and therapeutic strategies are warranted.

Background: Novel risk factors for stroke, such as occupation, are increasingly under exploration. We investigate if specific occupational exposures and settings increase the risk of developing small‐vessel disease (SVD), including SVD‐related strokes. Methods: We performed a systematic review on stroke–occupation associations and then analyzed data from patients presenting to Lothian stroke services with mild ischemic stroke (modified Rankin Scale score ≤2). We performed magnetic resonance imaging and inquired about occupational status. We assessed relationships between high‐risk occupations (per Control to Substances Hazardous to Health guidelines) and standard occupational classifications (per Standard Occupational Classifications criteria) against white matter hyperintensity volumes, SVD score, and stroke subtype. Results: Our systematic review identified 37 papers assessing occupations/broad occupational classifications (n=13), psychosocial work‐related factors (n=11), and occupational exposure to hazardous substances (n=13). We then analyzed data from 414 participants and found, after adjustment for age, hypercholesterolemia, socioeconomic status, years of education, hypertension, diabetes, and smoking history, that high‐risk occupations were associated with higher SVD scores (odds ratio, 1.64 [95% CI, 1.07–2.54]; n=357; P =0.02) but not for lacunar stroke subtype (odds ratio, 1.03 [95% CI, 0.64–1.67]; n=358; P =0.90) or white matter hyperintensity volume (% intracranial volume) (β=−0.003 [95% CI, −0.015 to 0.008]; n=357; P =0.60). Examples of high‐risk occupations include drivers, engineers, and skilled trade workers. No associations were found for standard occupational classifications. Conclusions: This systematic review shows limited data on stroke–occupation associations. Our analysis showed that high‐risk occupations are associated with higher SVD scores but not stroke subtype. Registration: URL: www.crd.york.ac.uk/PROSPERO ; Unique Identifier: 42024466671.

Background: Stenosis and dolichoectasia of cranial arteries likely reflect distinct mechanisms. Their contributions to lacunar stroke and cerebral small vessel disease (cSVD) remain contentious. We investigated associations of large artery stenosis (LAS) and arterial widening with stroke subtype, cSVD markers, incident infarcts, and clinical outcomes. Methods: We prospectively recruited patients with lacunar or mild non-lacunar stroke, with demographic, stroke-related, cognitive, functional, and MRI (index and incident infarcts, cSVD markers) assessments at baseline and one year. LAS was defined as ≥50% intracranial or cervical artery stenosis; basilar artery dolichoectasia (BADE) by basilar artery diameter, bifurcation height, and lateral displacement; and intracranial carotid and middle cerebral artery diameters were also measured. Associations were estimated using multivariable regression adjusted for age, sex, and vascular risk factors. We further conducted a systematic literature review to synthesize evidence on relationships between large artery pathology and cSVD. Results: Among 229 patients (mean age 65.9±11.1 years; 131 [57.2%] lacunar stroke), LAS and BADE were present in 20.5% and 15.7%, respectively. After adjustment, LAS (odds ratio [OR], 0.49; 95%CI, 0.23-0.99) and the presence of any embolic source were associated with lower odds of lacunar versus non-lacunar stroke, and not with cSVD markers or incident infarcts. In contrast, BADE was strongly associated with lacunar stroke (OR, 4.67; 95%CI, 1.87-13.14), higher cSVD scores (ordinal analysis; OR, 2.57; 95%CI, 1.28-5.25), incident infarcts (75% subcortical; OR, 2.29; 95%CI, 1.01-5.14), and greater progression of white matter hyperintensities over one year (β, 0.15; 95%CI, 0.01-0.29; per log ₁₀ -transformed volume). Similar associations were observed for wider intracranial arteries. The systematic review supported these findings. Conclusions: cSVD, including lacunar stroke, was unrelated to LAS, but strongly associated with dolichoectasia and wider arteries. These findings support a non-atheromatous, intrinsic microvascular pathology, particularly segmental arteriolar disorganization, as the principal mechanism of lacunar stroke and cSVD. Mechanism-specific diagnostic and therapeutic strategies are warranted. Clinical Perspective: What Is New?: ● Large artery stenosis was unlikely to represent a causal mechanism for lacunar stroke and showed no association with cerebral small vessel disease (cSVD) imaging markers. ● Dolichoectasia and intracranial arterial widening emerged as vascular phenotypes strongly associated with cSVD, including its progression and lacunar stroke subtype. What Are the Clinical Implications?: ● Distinct large artery phenotypes have divergent etiopathological implications for cSVD. Our findings support a non-atheromatous, intrinsic microvascular pathology as the principal mechanism of lacunar stroke and cSVD. ● Mechanism-based therapeutic strategies for lacunar stroke and cSVD, moving beyond conventional approaches focused on atherosclerosis or cardioembolism, are warranted.

BACKGROUND: The impact of covert cerebrovascular disease on falls in the general population is not well-known. Here, we determine the time to a first fall following incidentally detected covert cerebrovascular disease during a clinical neuroimaging episode. METHODS: This longitudinal cohort study assessed computed tomography (CT) and magnetic resonance imaging from 2009 to 2019 of patients aged >50 years registered with Kaiser Permanente Southern California which is a healthcare organization combining health plan coverage with coordinated medical services, excluding those with before stroke/dementia. We extracted evidence of incidental covert brain infarcts (CBI) and white matter hyperintensities/hypoattenuation (WMH) from imaging reports using natural language processing. We examined associations of CBI and WMH with falls requiring medical attention, using Cox proportional hazards regression models with adjustment for 12 variables including age, sex, ethnicity multimorbidity, polypharmacy, and incontinence. RESULTS: We assessed 241 050 patients, mean age 64.9 (SD, 10.42) years, 61.3% female, detecting covert cerebrovascular disease in 31.1% over a mean follow-up duration of 3.04 years. A recorded fall occurred in 21.2% (51 239/241 050) during follow-up. On CT, single fall incidence rate/1000 person-years (p-y) was highest in individuals with both CBI and WMH on CT (129.3 falls/1000 p-y [95% CI, 123.4–135.5]), followed by WMH (109.9 falls/1000 p-y [108.0–111.9]). On magnetic resonance imaging, the incidence rate was the highest with both CBI and WMH (76.3 falls/1000 p-y [95% CI, 69.7–83.2]), followed by CBI (71.4 falls/1000 p-y [95% CI, 65.9–77.2]). The adjusted hazard ratio for single index fall in individuals with CBI on CT was 1.13 (95% CI, 1.09–1.17); versus magnetic resonance imaging 1.17 (95% CI, 1.08–1.27). On CT, the risk for single index fall incrementally increased for mild (1.37 [95% CI, 1.32–1.43]), moderate (1.57 [95% CI, 1.48–1.67]), or severe WMH (1.57 [95% CI, 1.45–1.70]). On magnetic resonance imaging, index fall risk similarly increased with increasing WMH severity: mild (1.11 [95% CI, 1.07–1.17]), moderate (1.21 [95% CI, 1.13–1.28]), and severe WMH (1.34 [95% CI, 1.22–1.46]). CONCLUSIONS: In a large population with neuroimaging, CBI and WMH are independently associated with greater risks of an index fall. Increasing severities of WMH are associated incrementally with fall risk across imaging modalities.

BACKGROUND: Cerebral small vessel disease (SVD) causes up to 45% of dementias and 25% of ischemic strokes, but the understanding of vascular pathophysiology is limited. We aimed to investigate the contribution of pulsatility of intracranial arteries, veins, and cerebrospinal fluid (CSF) and cerebral blood flow to long-term imaging and clinical outcomes in SVD. METHODS: We prospectively recruited participants in Edinburgh/Lothian, Scotland, with lacunar or nonlacunar ischemic stroke (modified Rankin Scale score ≤2, as controls) and assessed medical and brain magnetic resonance imaging characteristics at baseline and 1 year (2018–2022). We used phase-contrast magnetic resonance imaging to measure flow and pulsatility in major cerebral vessels and CSF to investigate independent associations with baseline white matter hyperintensity (WMH) and perivascular space (PVS) volumes and their progression, as well as with recurrent stroke, functional, and cognitive outcomes at 1 year. We applied linear, logistic, and ordinal regression models in our analysis. RESULTS: We recruited 210 participants; 205 (66.8% male; aged 66.4±11.1 years) had useable data. In covariate-adjusted analyses, higher baseline arterial pulsatility was associated with larger volumes of baseline WMH (B=0.26 [95% CI, 0.08–0.44]; P =0.01) and basal ganglia PVS (B=0.12 [95% CI, 0.04–0.20]; P P =0.78; basal ganglia PVS: B=0.02 [95% CI, −0.04 to −0.07]; P =0.62) or cognition, dependency, or recurrent stroke at 1 year. Neither cerebral blood flow nor CSF pulsatility was related to baseline SVD severity, WMH/PVS progression, or clinical outcomes at 1 year. CONCLUSIONS: Associations between vascular/CSF pulsatility, cerebral blood flow, WMH/PVS, and clinical SVD features are complex. The lack of association between intracranial arterial, venous, or CSF pulsatility, cerebral blood flow, and WMH or PVS longitudinal change in this large, covariate-adjusted analysis questions the presumption that high intracranial vascular pulsatility causes SVD and its progression, consistent with other recent longitudinal studies. Intracranial pulsatility may differ from systemic vascular measures in their cause-pathogenic role(s) in SVD and should be considered separately.

Disturbed sleep is common after stroke, yet its relationship with cerebral small vessel disease (SVD) and cognitive performance in the stroke population, particularly patients with TIA/mild stroke who are on the milder end of the cerebrovascular spectrum, remains understudied. We aim to examine the associations of self-reported sleep metrics with neuroimaging markers of SVD and cognitive performance in patients with TIA/mild stroke from 2 prospective stroke cohorts. We studied adult patients with TIA/mild stroke (NIH Stroke Scale [NIHSS] score summary SVD score = 1.27 per 1-SD increase (95% CI 1.05-1.53), false discovery rate (FDR)-adjusted p = 0.04; OR_{periventricular WMH} = 1.53 per 1-SD increase (95% CI 1.18-2.00), p = 0.003. Longer sleep duration was independently associated with presence of cerebral microbleeds: OR = 1.42 per 1-SD increase (95% CI 1.09-1.87), p = 0.04. Longer in-bed time was associated with a lower total MoCA score after covariate adjustment: standardized β = -0.58 (95% CI -0.99 to -0.16), p = 0.02. Disturbed sleep, including longer in-bed time and longer sleep duration, was cross-sectionally associated with greater SVD burden and worse cognitive performance in patients with TIA/mild stroke. Future longitudinal studies are warranted to validate our findings.