Pathogenic Heterogeneity of Distal Single Small Subcortical Lenticulostriate Infarctions Based on Lesion Size

Lesion Indexes Predict Early Neurologic Deterioration in Lenticulostriate Single Small Subcortical Infarction

BACKGROUND AND PURPOSE

Early neurologic deterioration (END) often occurs during hospitalization in single small subcortical infarction (SSSI). The objective was to identify imaging predictors of END.

MATERIALS AND METHODS

SSSIs in the lenticulostriate artery within 72 hours of stroke onset from January 2015 to June 2021 were consecutively enrolled. The posteriority and laterality indexes were assessed on the second section from the top of the corona radiata section showing the lateral ventricle on DWI. A multivariate logistic analysis was used to explore the predictors of END.

RESULTS

A total of 402 patients were included in this study, among whom 93 (23.1%) experienced END. The optimal cutoff points of the posteriority and laterality indexes for predicting END were given by a receiver operating characteristic curve. A multivariate logistic analysis showed that the posteriority index of ≥0.669 (OR: 2.53; 95% CI: 1.41-4.56; P = .002) and the laterality index of ≥0.950 (OR: 2.03; 95% CI: 1.03-4.00; P = .042) were independently associated with the risk of END. Accordingly, the SSSIs were further divided into 4 types: anterior lateral type (AL-type), anterior medial type (AM-type), posterior lateral type (PL-type), and posterior medial type (PM-type). After the multivariate analysis, in comparison with the AL-type, the AM-type (OR: 3.26; 95% CI: 1.10-9.65), PL-type (OR: 4.68; 95% CI: 1.41-15.56), and PM-type (OR: 6.77; 95% CI: 2.53-18.04) carried significantly elevated risks of END. The PM-type was associated with the highest risk of END.

CONCLUSIONS

The PM-type was found to be associated with the highest risk of END.

Infarct growth velocity predicts early neurological outcomes in single subcortical infarction

In single subcortical infarction (SSI), changes in lesion size are a major determinant of early neurological deterioration. We evaluated the association between END and infarct growth velocity (IGV) in patients with SSI. We included consecutive patients with SSI who underwent MRI within 24 h of symptom onset between 2010 and 2020. END was defined as an increase of ≥ 2 in the total National Institutes of Health Stroke Scale (NIHSS) score or ≥ 1 in the motor NIHSS score. IGV was calculated using the following formula: IGV (mL/h) = diffusion-weighted imaging volume (mL)/time to MRI (h). A total of 604 patients with SSI were evaluated. Multivariable logistic regression analysis showed that IGV remained significant after adjusting for confounders (aOR = 1.34, 95% CI 1.12-1.61). In a subgroup analysis based on the type of SSI, only patients with distal SSI showed an association between IGV and END (aOR = 1.64, 95% CI 1.24-2.16). In patients with proximal SSI, IGV did not show any statistical association with END. In conclusion, IGV was positively associated with END in patients with SSI. IGV should be interpreted differently in clinical settings depending on the location of the SSI lesion.

A method to distinguish the different etiological mechanisms of single subcortical infarction

OBJECTIVES

Although lenticulostriate artery (LSA) territorial infarcts usually appear as single subcortical infarctions (SSIs) on imaging, they are caused by various etiological mechanisms. We aimed to investigate the correlation between LSA morphology and the location or size of infarcts. Besides, we explored whether the location or size of infarcts can predict the presence of middle cerebral artery (MCA) plaques and distinguish the different etiological mechanisms of SSI patients.

METHODS

We prospectively included patients with acute SSI in the LSA territory. The MCA plaques, infarct features, including the number of infarct slices, lowest infarct layer index (LILI), volume, maximum area and diameter, and LSA morphological characteristics, including the number of stems and branches, length, distance, and tortuosity were evaluated.

RESULTS

A total of 105 patients were enrolled. Both the average length and average distance of LSAs were negatively correlated with the maximum infarct area (P=0.048, P=0.028, respectively) and maximum infarct diameter (P=0.016, P=0.010, respectively) on axial examination and were positively correlated with LILI (P=0.020, P=0.003, respectively). The number of LSA branches was associated with the number of infarct slices (P=0.040) and LILI (P=0.043). Moreover, we found that when the LILI=1 or 2 and the number of infarct slices ≥3, the SSI patients were more likely to have MCA plaques (P=0.045).

CONCLUSIONS

SSI patients with a LILI=1 or 2 and infarct slices of ≥3 were more likely to have MCA plaques. Our findings might provide a simple and feasible method to distinguish the different underlying mechanisms of SSIs for clinicians.

Clopidogrel Plus Aspirin in Patients With Different Types of Single Small Subcortical Infarction

Background: We aim to investigate the effects and safety of clopidogrel plus aspirin in patients with different types of single small subcortical infarction (SSSI) in the Clopidogrel in High-risk patients with Acute Non-disabling Cerebrovascular Events (CHANCE) trial. Methods: SSSI was defined as single DWI lesion of ≤2.0 cm. Patients with SSSI were divided into SSSI + PAD (parent artery disease) and SSSI - PAD, according to the stenosis of the parent artery. The efficacy outcome was stroke recurrence during 90-day follow-up. Cox proportional hazards models or logistic regression models were used to assess the interaction of the treatment effects of clopidogrel plus aspirin vs. aspirin alone among patients with and without PAD. Results: Among 338 patients with SSSI included in the subanalysis, 105 were with PAD and 233 without. The efficacy of clopidogrel plus aspirin compared with aspirin alone on any stroke was consistent between patients with [adjusted hazard ratio (HR) 0.84; 95% confidence interval (CI), 0.25-2.75] and without PAD (adjusted HR 1.03; 95% CI, 0.40-2.68, interaction P = 0.83). In patients with SSSI + PAD, the rate of stroke recurrence in those treated with dual antiplatelet therapy and mono antiplatelet therapy was not significantly different (10.9 vs. 13.6%, P = 0.77). The number of bleeding events was similar between the clopidogrel-aspirin group and aspirin group regardless of SSSI + PAD or SSSI - PAD. Conclusions: There was no significant difference in the efficacy of clopidogrel plus aspirin compared with aspirin alone between patients with SSSI + PAD and SSSI - PAD in the CHANCE trial. Studies in other populations and with adequate power are needed to further verify such findings.