Are multiple acute small subcortical infarctions caused by embolic mechanisms?

Seasonal variability of lesions distribution in acute ischemic stroke: A retrospective study

Seasonal variability could have an impact on the incidence and outcome of stroke. However, little is known about the correlation between seasonal variability and location of acute cerebral infarction. This study aimed to explore the relationship between onset season and the lesions distribution of acute ischemic stroke (AIS). We retrospectively analysis data from 1488 AIS patients admitted to the Second Hospital of Tianjin Medical University from 2018 to 2022. All subjects completed head magnetic resonance imaging examination (MRI) and were divided into four groups according to the onset seasons. The lesions distribution of AIS was evaluated for anterior/posterior/double circulation infarction (DCI), unilateral/bilateral infarctions, and single/multiple cerebral infarctions based on MRI. Logistic regression models were employed to assess the association of season with lesions distribution of AIS. Subgroup analysis was performed in different stroke subtypes. Of 1488 patients, 387 (26.0%) AIS occurred in spring, 425 (28.6%) in summer, 331 (22.2%) in autumn and 345 (23.2%) in winter. Multivariate logistic regression demonstrated that the winter group had 2.15 times (95% CI:1.44-3.21) risk of multiple infarctions, 2.69 times (95% CI:1.80-4.02) of bilateral infarctions and 1.54 times (95% CI:1.05-2.26) of DCI compared with summer group, respectively. Subgroup analysis showed an increased risk of multiple (p < 0.01) or bilateral infarctions (p < 0.01) in small-artery occlusion (SAO) subtype, and higher risk of bilateral infarctions (p < 0.01) or DCI (p < 0.05) in large artery atherosclerosis (LAA) subtype during winter. No significant associations of season with lesions distribution in cardioembolism subtype. Our study highlighted a prominent seasonal variability in the lesions distribution of AIS, particularly in LAA and SAO subtypes. The findings could help to formulating meteorological risk warning strategies for different subtypes.

Acute simultaneous multiple lacunar infarcts: a severe disease entity in small artery disease

BACKGROUND

We hypothesized that acute simultaneous multiple lacunar infarcts (sMLI) may have different clinico-radiological characteristics compared to acute single lacunar infarcts (SLI).

METHODS

We retrospectively reviewed stroke patients with sMLI or SLI in a consecutively collected stroke registry with a predefined long-term clinical follow-up. Clinical characteristics, including vascular risk factors, rheological profiles, premorbid functional status, and clinical outcome were evaluated. In addition, radiological characteristics, including white matter ischemic changes, previous lacunes, microbleeds, and concomitant intra- or extracranial arterial stenosis were evaluated.

RESULTS

Of the 548 acute ischemic stroke patients, sMLI was found in 23 (13.5%) and SLI in 148 (86.5%). There was no difference in vascular risk factors and rheological profiles between the two groups, except for advanced age and more frequent previous history of stroke in the sMLI group. The sMLI group also showed more previous lacunes (p < 0.001) and microbleeds (p < 0.001). A cardioembolic or atherothrombotic stroke mechanism was rare in both groups. Recurrent strokes were more frequent in the sMLI group.

CONCLUSIONS

The main pathophysiology of sMLI may be small artery disease. However, clinico-radiological characteristics suggest that sMLI may be a more severe entity of small artery disease compared to SLI.

Differing risk factors and outcomes in ischemic stroke subtypes: focus on lacunar stroke

Lacunar stroke has been a recognized stroke subtype for many years but its pathophysiology remains unknown, so prevention and treatment are suboptimal. Most lacunar strokes result from an intrinsic cerebral small vessel disease, probably part of a systemic disorder. Hypertension, diabetes and other vascular risk factors (but not atrial fibrillation and ipsilateral carotid stenosis) are equally common in lacunar as in large artery atherothromboembolic stroke, which, together with other factors, suggests that the patient’s response to vascular risk factors, not the vascular risk factors per se, determines whether they develop small vessel or large artery stroke. Inflammation and endothelial failure are probably involved in the pathogenesis of lacunar stroke, but their role needs to be clarified. The cerebral venules as well as arterioles are abnormal in this condition. The disorder may not be primarily ischemic; instead, arteriolar thrombosis may be a late-stage phenomenon secondary to chronic arteriolar wall damage resulting from leakage of plasma components across the BBB. Accurate diagnosis of lacunar stroke, avoiding risk factor-based classifications, is required to underpin future research.