Highlights
In this prospective cohort of patients with lacunar or mild nonlacunar stroke, large-artery stenosis of 50% or greater was associated with lower odds of lacunar stroke and showed no meaningful relationship with cerebral small-vessel disease markers or incident infarcts over 1 year.
By contrast, basilar artery dolichoectasia and wider intracranial arteries were strongly associated with lacunar stroke, greater baseline cSVD burden, more incident infarcts, and progression of white matter hyperintensities.
The findings argue against atherosclerotic stenosis as the principal driver of lacunar stroke in most patients and instead support a nonatheromatous intrinsic arteriolar process, particularly segmental arteriolar disorganization, as a central mechanism of cSVD.
These data have potentially important diagnostic and therapeutic implications, suggesting that mechanism-specific stratification may be more informative than treating lacunar stroke as a downstream consequence of proximal arterial narrowing.
Background
Lacunar stroke and cerebral small-vessel disease are major contributors to stroke disability, cognitive decline, gait dysfunction, mood symptoms, and vascular dementia. Yet the underlying vascular mechanism remains debated. One enduring question is whether cSVD arises primarily from disease intrinsic to the perforating arterioles and capillary bed, or whether it is often secondary to pathology in the parent large arteries, especially atherosclerotic stenosis that might compromise perforator flow or generate artery-to-artery emboli.
This distinction matters clinically. If lacunar infarction is commonly driven by proximal large-artery stenosis, clinicians might prioritize vascular imaging findings such as carotid or intracranial narrowing when assigning mechanism and selecting prevention strategies. If, however, cSVD is more closely linked to arterial remodeling characterized by widening, elongation, and tortuosity rather than stenosis, then current mechanistic models and perhaps some therapeutic assumptions need revision.
Dolichoectasia is one such remodeling phenotype. It refers to abnormal arterial dilation, elongation, and tortuosity, most classically affecting the basilar artery but also measurable in other intracranial vessels. Although often discussed in relation to compression syndromes, stroke risk, and diffuse arteriopathy, its relationship to lacunar stroke and MRI markers of cSVD has remained incompletely defined.
Han and colleagues address this issue in a carefully phenotyped prospective mild stroke cohort, supplemented by a systematic review of the literature. Their study asks a clinically sharp question: which large-vessel abnormalities, stenosis or widening, align with the biology and imaging phenotype of cSVD?
Proposed article structure
The topic is best organized around five elements: the clinical problem and mechanistic controversy; study design and imaging definitions; core results separating stenosis from dolichoectasia; biological interpretation and implications for stroke classification; and limitations, research priorities, and practice relevance. This structure mirrors how clinicians approach causation, imaging, and management in lacunar stroke.
Study Design and Methods
Design and population
This was a prospective cohort study of 229 patients with either lacunar stroke or mild nonlacunar stroke. The mean age was 65.9±11.1 years, and 131 participants, or 57.2%, had lacunar stroke. Patients underwent detailed baseline phenotyping and 1-year follow-up.
Clinical and imaging assessment
The investigators collected demographic variables, vascular risk factors, stroke subtype data, cognitive and functional measures, and MRI markers at baseline and follow-up. MRI evaluation included index infarcts, incident infarcts during follow-up, and established cSVD markers, with overall burden summarized using cSVD scores. White matter hyperintensity progression was also quantified.
Exposure definitions
Large-artery stenosis was defined as 50% or greater stenosis in an intracranial or cervical artery. Basilar artery dolichoectasia was characterized using diameter, bifurcation height, and lateral displacement. The authors also measured intracranial carotid and middle cerebral artery diameters, allowing them to test whether the signal was specific to the basilar artery or reflected a broader arterial widening phenotype.
Statistical analysis
Associations were estimated using multivariable logistic regression, linear regression, and proportional odds models adjusted for age, sex, and vascular risk factors. This analytic strategy is appropriate for a dataset containing binary outcomes such as stroke subtype, ordinal outcomes such as cSVD burden scores, and continuous imaging measures such as white matter hyperintensity volume change.
Systematic review
To place the cohort findings in context, the authors also performed a systematic literature review evaluating links between large-artery pathology and cSVD. This is an important addition because the field has historically contained heterogeneous and sometimes conflicting observational evidence.
Key Findings
Prevalence of vascular abnormalities
Among the 229 patients, 20.5% had large-artery stenosis and 15.7% had basilar artery dolichoectasia. These are not trivial frequencies in a mild stroke population and underscore why mechanism attribution can be challenging in routine practice: more than one vascular abnormality may coexist, but not all abnormalities are necessarily causally relevant to the presenting infarct pattern.
Large-artery stenosis did not support a lacunar mechanism
After adjustment, large-artery stenosis was associated with lower, not higher, odds of lacunar versus nonlacunar stroke, with an odds ratio of 0.49 and a 95% confidence interval of 0.23 to 0.99. The presence of any embolic source showed a similar directional association with lower odds of lacunar stroke. These results align with the intuitive concept that proximal stenotic and embolic mechanisms are more characteristic of nonlacunar ischemic stroke phenotypes.
Equally important, large-artery stenosis was not associated with cSVD markers or with incident infarcts over follow-up. That negative result is central to the paper. If stenosis were a major driver of cSVD, one might expect higher cSVD scores, more new infarcts, or faster white matter injury progression in those with stenosis. The study did not show that.
Basilar artery dolichoectasia strongly tracked with cSVD
Basilar artery dolichoectasia told a very different story. It was strongly associated with lacunar stroke, with an adjusted odds ratio of 4.67 and a 95% confidence interval of 1.87 to 13.14. This is a large effect size for an observational neurovascular study and supports a robust association between arterial widening/tortuosity and the lacunar phenotype.
Dolichoectasia was also associated with greater baseline cSVD burden. In ordinal analysis, the odds ratio for higher cSVD score was 2.57, with a 95% confidence interval of 1.28 to 5.25. Thus, the association was not limited to the index event but extended across the broader MRI signature of small-vessel brain injury.
Association with ongoing brain injury over 1 year
The prospective imaging results further strengthen the mechanistic argument. Basilar artery dolichoectasia was associated with incident infarcts during follow-up, with an odds ratio of 2.29 and a 95% confidence interval of 1.01 to 5.14. Notably, 75% of these incident infarcts were subcortical, which is highly relevant because subcortical location is compatible with cSVD-related injury.
Dolichoectasia was also linked to greater progression of white matter hyperintensities over 1 year, with a beta coefficient of 0.15 per log10-transformed volume and a 95% confidence interval of 0.01 to 0.29. White matter hyperintensity progression is a meaningful imaging marker because it correlates with future stroke, cognitive impairment, and functional decline. A vascular phenotype associated with both new infarcts and WMH progression is difficult to dismiss as incidental.
Signal extends beyond the basilar artery
Importantly, similar associations were seen for wider intracranial arteries more generally, including the intracranial carotid and middle cerebral arteries. This broadens the relevance of the findings beyond isolated vertebrobasilar ectasia. The data suggest a generalized intracranial arterial remodeling phenotype rather than a basilar-specific structural curiosity.
Systematic review findings
The authors report that the systematic review supported the cohort findings. While the abstract does not enumerate every included study, this convergence matters. Prospective cohort data can still be vulnerable to sampling variation and residual confounding, but alignment with the wider literature increases confidence that the observed pattern is real: cSVD appears to align more with arterial dilation and elongation than with stenotic atherosclerosis.
Clinical Interpretation
The most practice-relevant message is that clinicians should be cautious about inferring a causal link between incidental large-artery stenosis and a lacunar stroke pattern. This study suggests that when lacunar infarction occurs, large-artery stenosis may often be a bystander or a marker of generalized vascular risk rather than the direct cause of the small subcortical lesion.
Conversely, arterial widening and dolichoectasia may be imaging markers of the same diffuse vasculopathy that also affects small penetrating vessels. The authors interpret this in support of a nonatheromatous intrinsic microvascular pathology, particularly segmental arteriolar disorganization. That concept is biologically plausible. If extracellular matrix remodeling, vessel wall weakening, impaired autoregulation, and abnormal pulsatility affect both large intracranial arteries and downstream perforators, then ectasia and cSVD could represent parallel expressions of one arteriopathy rather than separate diseases.
This interpretation also helps explain why wider arteries, despite not being stenotic, might associate with ongoing subcortical injury. Abnormal arterial compliance and flow pulsatility can transmit damaging hemodynamic energy into fragile distal microvessels, promoting endothelial dysfunction, blood-brain barrier disruption, white matter injury, and small deep infarction. That framework is increasingly consistent with modern cSVD biology.
Strengths of the Study
The study has several notable strengths. First, it was prospective and included 1-year MRI follow-up, allowing assessment of incident lesions and WMH progression rather than relying only on cross-sectional associations. Second, stroke subtype adjudication was embedded in a clinically relevant cohort of mild stroke patients, which reduces some of the heterogeneity seen in broader stroke registries. Third, the investigators evaluated both stenosis and arterial widening within the same analytical framework, making the contrast between these mechanisms especially informative. Fourth, adjustment for age, sex, and vascular risk factors strengthens the inference that the observed associations were not simply due to shared conventional risk factor burden.
Limitations and Cautions
As with any observational study, causality cannot be definitively established. Although the prospective imaging findings support a temporal relationship with ongoing injury, residual confounding remains possible. The cohort size, while substantial for an imaging-intensive study, still limits power for some subgroup analyses and may widen confidence intervals around secondary outcomes.
The population consisted of patients with lacunar or mild nonlacunar stroke, so generalizability to severe stroke, asymptomatic populations, or ethnically distinct cohorts may be incomplete. Definitions of dolichoectasia, although standardized in this study, vary across the literature, which has complicated prior comparisons. In addition, the abstract does not provide detailed treatment data during follow-up, so it is difficult to know whether antithrombotic, antihypertensive, or lipid-lowering regimens modified observed associations.
Another practical issue is that large-artery stenosis may still matter in selected patients with branch atheromatous disease or proximal plaque affecting perforator origins, entities that can mimic or overlap with lacunar syndromes. The present findings should not erase those possibilities, but they do suggest such mechanisms are unlikely to explain the broader cSVD phenotype at the population level.
Implications for Practice and Research
For clinical practice, the study supports more disciplined mechanistic classification of ischemic stroke. A patient with a small deep infarct and coexisting carotid or intracranial stenosis should not automatically be labeled as having large-artery atherosclerotic stroke without supportive anatomical and imaging evidence. MRI pattern, vessel imaging, and the overall cSVD burden should be integrated carefully.
For research, these findings encourage deeper study of arterial stiffness, vessel wall biology, extracellular matrix pathways, and pulsatility-related injury across the large-artery-to-arteriole continuum. Future work should test whether cranial arterial diameter and tortuosity can improve prognostic models for recurrent subcortical infarction, WMH progression, cognitive decline, or gait impairment.
There is also a therapeutic implication. If lacunar stroke and cSVD are principally manifestations of intrinsic arteriolar disease rather than embolic or stenotic atherosclerotic disease, then prevention strategies may need to move beyond traditional antithrombotic escalation and focus more specifically on blood pressure control, vascular compliance, endothelial health, and perhaps future disease-modifying approaches targeting microvascular remodeling.
Expert Commentary
This study fits with a broader shift in stroke neurology: cSVD is increasingly viewed not as a minor variant of atherosclerotic cerebrovascular disease but as a distinct arteriopathy with its own imaging signatures, biological mechanisms, and clinical trajectories. The present findings sharpen that distinction by showing that not all large-vessel abnormalities point toward the same causal pathway. Narrowed arteries and widened arteries may represent fundamentally different vascular phenotypes with very different implications for stroke mechanism.
The paper is also a reminder that vascular imaging interpretation should move beyond the binary presence or absence of stenosis. Arterial geometry, caliber, elongation, and tortuosity may carry important pathophysiologic information, particularly in patients with lacunar syndromes, confluent white matter disease, and recurrent subcortical lesions.
Conclusion
In this prospective mild stroke cohort, large-artery stenosis was not associated with cerebral small-vessel disease and was linked to lower odds of lacunar versus nonlacunar stroke. In contrast, basilar artery dolichoectasia and wider intracranial arteries were strongly associated with lacunar stroke, greater cSVD burden, incident predominantly subcortical infarcts, and progression of white matter hyperintensities. Taken together, these findings support a nonatheromatous intrinsic microvascular mechanism, rather than proximal stenotic atherosclerosis, as the principal driver of lacunar stroke and cSVD in most patients. The study has clear implications for stroke mechanism attribution, imaging interpretation, and development of more targeted preventive strategies.
Funding and ClinicalTrials.gov
The abstract provided does not report funding details or a ClinicalTrials.gov registration number. Readers should consult the full Circulation article for complete funding disclosures and study governance information.
Reference
Han F, Clancy U, Arteaga-Reyes C, Thrippleton MJ, Valdés Hernández MDC, Jaime Garcia D, Stringer MS, Backhouse E, Chappell FM, Cheng Y, Liu DX, Zhang J, Jochems ACC, Sakka E, Jardine C, Barclay G, McIntyre D, Hamilton I, Brown R, Zhu YC, Doubal FN, Wardlaw JM. Implications of Cranial Arterial Stenosis and Dolichoectasia for Cerebral Small-Vessel Disease Etiopathogenesis: Findings From a Prospective Mild Stroke Cohort. Circulation. 2026-05-06. PMID: 42090170. URL: https://pubmed.ncbi.nlm.nih.gov/42090170/