Post-stroke cognitive impairment - A cross-sectional comparison study between mild cognitive impairment of vascular and non-vascular etiology.

Purpose: To elucidate the cognitive profiles of post-stroke vascular mild cognitive impairment (VaMCI) in comparison to MCI of non-vascular etiology and cognitively normal healthy controls at a tertiary-care hospital in southern India.

Results: Logistic regression analysis adjusted for age and sex comparing VaMCI [N=50] with controls [N=27] revealed significant impairment in visual, verbal learning-recall and executive function scores. As compared to the MCI group [N=36], VaMCI had significantly higher scores on Weschler's Memory Scale (WMS) verbal subset delayed recall scores (p=0.045, odds ratio [OR]=2.62, 95% CI=1.02-6.76) with lower scores on WMS-visual immediate learning scores (p=0.042, OR=0.35, 95% CI=0.13-0.96), Rey Auditory Verbal Learning Test (RAVLT) total learning scores (p=0.001, OR=0.17, 95% CI=0.06-0.48) and 20 minute recall (p=0.026, OR=0.33, 95% CI=0.12-0.88), Delayed Matching to Sample test (DMS-48) abstract immediate (p=0.002, OR=0.20, 95% CI=0.07-0.56), abstract delayed recognition sub-sets (p=0.014, OR=0.28, 95% CI=0.10-0.78) and made more total errors on Wisconsin Card Sorting Test (WCST; p=0.040, OR=2.70, 95% CI=1.05-7.14) while the MCI group significantly had more commission errors on RAVLT (p≤0.001, OR=0.13, 95% CI=0.05-0.38) and WCST - perseverative errors (p=0.036, OR=0.30, 95% CI=0.10-0.93). Significant differences were noted in word-list learning-recall (p=0.012) and WMS verbal delayed recall (p=0.014) between VaMCI with mild versus moderate to severe deep white matter hyperintensities on neuroimaging.

Conclusions: Cognitive impairment following minor stroke involves episodic verbal and visual memory over and above executive function in comparison to MCI of non-vascular etiology. Close cognitive followup is warranted with adequate risk stratification and management especially in the presence of sub-cortical leukoaraiosis which is contributory to cognitive decline in this group of patients.