New publication in Neurology
Publication date: February 2022
Publication title: "Impact of Small Vessel Disease Progression on Long-term Cognitive and Functional Changes After Stroke"
Authors: Clancy U, Makin SD, McHutchison CA, Cvoro V, Chappell FM, Hernández MDCV, Sakka E, Doubal, F. N., Wardlaw, J. M.
Background and objectives: The severity of white matter hyperintensities (WMH) at presentation with stroke associates with post-stroke dementia and dependency. However, WMH can decrease or increase after stroke, prediction of cognitive decline is imprecise, and there are few data assessing longitudinal interrelationships between changing WMH, cognition, and function after stroke, despite the clinical importance.
Methods: We recruited patients within three months of a minor ischaemic stroke, defined as NIHSS score <8 and not expected to result in a modified Rankin Score (mRS) >2. Participants repeated MRI at one year, and cognitive and mRS assessments at one and three years. We ran longitudinal mixed-effects models assessing change in Addenbrooke's Cognitive Examination-Revised (ACE-R) and modified Rankin Scores (mRS). For mRS, we assessed longitudinal WMH volumes (cube root; percentage intracranial volume [ICV]), adjusting for age, NIHSS, ACE-R, stroke subtype, and time to assessment. For ACE-R, we additionally adjusted for ICV, mRS, premorbid IQ, and vascular risk factors. We then used a multivariate model to jointly assess changing cognition/mRS, adjusted for prognostic variables, using all available data.
Results: We recruited 264 patients; mean age was 66.9 (SD 11.8); 41.7% were female; median mRS 1 (IQR 1-2). One year after stroke, normalised WMH volumes associated more strongly with one-year ACE-R (β= -0.259, 95% confidence interval [CI] -0.407 to -0.111 more WMH per 1-point ACE-R decrease, p=0.001) compared to subacute WMH volumes and ACE-R (β=0.105, 95%CI -0.265 to 0.054, p=0.195). Three-year mRS associated with three-year ACE-R (β=-0.272, 95%CI -0.429 to -0.115, p=0.001). Combined change in baseline-one-year jointly assessed ACE-R/mRS associated with fluctuating WMH volumes (F=9.3, p=0.03).
Discussion: After stroke, fluctuating WMH mean that one-year, but not baseline, WMH volumes associate strongly with contemporaneous cognitive scores. Co-varying longitudinal decline in cognition and independence post-stroke, central to dementia diagnosis, is associated with increasing WMH volumes.