A combination of decline in cognition and independence is associated with the presence and progression of white matter hyperintensities (WMH) in the year after a stroke, according to a study in Neurology.
Previous research has found worse WMH at stroke presentation are associated with worse cognition concurrently and long term. However, it’s not clear whether longitudinal WMH change predicts co-existent post-stroke cognitive or functional impairment. The objective of the current study was to assess longitudinal interrelationships between changing white matter hyperintensities, cognition, and function after stroke.
A total of 264 patients who presented for stroke services in Edinburgh, UK, for an acute minor ischemic stroke were enrolled. The participants were evaluated 1 to 3 months post-stroke, which included magnetic resonance imaging (MRI), cognitive, and modified Rankin Score (mRS) assessments. The patients had a follow-up MRI at 1 year and additional cognitive and mRS assessments at 1 and 3 years. All patients underwent the Addenbrooke’s Cognitive Examination–Revised version (ACE-R) at all 3 visits.
The researchers recorded mRS, imaging, and cognitive data at baseline (mRS n = 264; imaging: n = 264; cognitive n = 157), 1 year (mRS n = 264; imaging: n = 196; cognitive n = 151), and 3 years post-stroke (mRS n = 222; no imaging; cognitive n = 152).
Participants’ mean age at baseline was 66.9 (SD 11.8) years, 41.7% were female, and their median mRS was 1 (interquartile range, 1-2).
ACE-R scores were very weakly associated with WMH volumes (cube root as % of intracranial volume [ICV]) (β = 0.105; 95% CI, -0.265 to 0.054 more WMH per 1-point ACE-R decrease; P =.195) at baseline. At 1 year, the associations between ACE-R scores and WMH volumes became more evident (β = -0.259; 95% CI, -0.407 to -0.111 more WMH per 1-point ACE-R decrease; P = .001). A strong ACE-R/mRS association was found at 3 years (β = -0.272; 95% CI -0.429 to -0.115; P =.001).
The changes in ACE-R scores were associated most strongly with age (β = -0.30; 95% CI, -0.44 to -0.16; P <.001) and National Adult Reading Test scores (β = 0.53; 95% CI, 0.40- 0.66; P <.001), followed by normalized WMH volume changes from baseline to 1 year (β = -0.113; 95% CI, -0.233-0.007; P =.065).
According to multivariate change-change analysis, patients who had a change in ACE-R and mRS from baseline to 1 year were more likely to have had a change from baseline to 1 year in their WMH volumes and NIH Stroke Scale scores compared with patients without any change in ACE-R and mRS.
The researchers noted that they did not invite participants to undergo MRI at 3 years and that longer-term WMH volumes would have strengthened their analysis and better reflected changes in WMH, cognition, and mRS at all 3 time points. Also, not all participants completed cognitive assessments, and depression was not included as a covariate.
The findings suggest “that dynamic WMH in the weeks after a stroke do not reflect permanent brain damage but by 1 year, perhaps when any modifiable component of WMH such as interstitial edema has cleared, WMH volumes may more closely represent the underlying ‘permanent’ damage and hence better correlate with cognition,” according to the researchers.
Clancy U, Makin SD, McHutchison CA, et al. Impact of small vessel disease progression on long-term cognitive and functional changes after stroke. Neurology. Published online February 7, 2022. doi:10.1212/WNL.0000000000200005