Different Characteristics of Incidental Diffusion-Weighted Imaging-Positive Lesions and Recent Small Subcortical...

The mechanisms underlying covert versus symptomatic acute infarcts in cerebral small vessel disease are unclear.

Based on the multicenter Cerebral Small Vessel Disease Disability and Outcome Cohort Study, we consecutively enrolled patients presenting with an acute lacunar stroke within 30 days or patients without acute stroke symptoms but with moderate to severe white matter hyperintensities. Between August 2016 and June 2019, 1710 patients (mean age 61.87±11.28 years, 37.25% female) were recruited across 30 hospitals in China. We compared the clinical and imaging characteristics between individuals with incidental diffusion-weighted imaging (DWI)-positive lesions and those with recent small subcortical infarcts (RSSI).

The prevalence of incidental DWI-positive lesions and RSSI was 2.28% and 31.64%. Patients with incidental DWI-positive lesions were older, had lower blood pressure and lipid levels, and more prior lacunar stroke. Incidental DWI-positive lesions were typically smaller and round/ovoid, more often involved the subcortical white matter and cerebral cortex. RSSI more frequently affected perforating artery territories, 39.9% of RSSI cases were consistent with branch atheromatous disease. Incidental DWI-positive lesions patients had a higher risk of 90-day recurrent stroke (hazard ratio [HR], 8.28 [95% CI, 1.96-34.90], log-rank P<0.001). They also had lower Mini-Mental State Examination scores after adjustment for age and sex.

Atherosclerosis and branch atheromatous disease appear to be predominant causes of RSSI among Chinese patients with cerebral small vessel disease. Incidental DWI-positive lesions likely reflecting intrinsic small vessel injury constitute a cerebral small vessel disease marker and carry prognostic value for stroke recurrence and cognitive decline.