Cognitive deficits after ischemic stroke are independently associated with poor long-term outcomes. We assessed whether MRI biomarkers, other than white matter hyperintensities, can aid in predicting cognitive impairment after small vessel stroke (SVS).
This was a retrospective analysis of a prospective cohort of patients enrolled in the American Stroke Association-Bugher Small Vessel Study. The study included 139 patients within 2-years of SVS. In addition to the extent of white matter disease (WMD), the following brain MRI characteristics were collected at the time of stroke: 1, total number of infarcts; 2, size of the largest lacune; 3, ventricular enlargement; 4, cerebral atrophy; and 5, supratentorial and/or infratentorial infarct location/s. The extent of WMD, cerebral atrophy, and ventricular enlargement were graded using the Cardiovascular Health Study (CHS) scores. Size of acute SVS was categorized as small (3 – 10 mm) or large (> 1 cm). The primary outcomes were: 1, total score on the short form of the Montreal Cognitive Assessment (SF MoCA) to assess global cognition; and 2, time to complete trails B to evaluate executive function. Linear regression analyses were performed using the five MRI characteristics of interest, adjusting for age, education, NIHSS score, and CHS WMD score. Patients with missing cognitive outcomes were excluded. A p-value ≤ 0.05 was considered statistically significant.
The median age was 62.9 years with 51.1% (n=71) women and 32.4% (n=45) Black. The median years of education was 12-years and median NIHSS was 1. The median WMD burden score was 3. There were no significant associations of any of the MRI characteristics with the SF MoCA. Only the extent of WMD was associated with the time to complete trails B (β 40.02; 95%CI 19.8-60.24, p=0.0001).
Among the included clinically available MRI characteristics, only the extent of WMD was associated with executive function after SVS.