Post-stroke Cognition at 1 and 3 Years Is Influenced by the Location of White Matter Hyperintensities in Patients With Lacunar Stroke

Lacunar strokes are a common type of ischemic stroke. They are known to have long-term cognitive deficits, but the influencing factors are still largely unknown. We investigated if the location of the index lacunar stroke or regional WMH and their change at 1 year could predict the cognitive performance at 1 and 3 years post-stroke in lacunar stroke patients. We used lacunar lesion location and WMH-segmented data from 118 patients, mean age 64.9 who had a brain MRI scan soon after presenting with symptoms, of which 88 had a repeated scan 12 months later. Premorbid intelligence (National Adult Reading Test) and current intelligence [Addenbrooke's Cognitive Exam-Revised (ACE-R)] were measured at 1, 12, and 36 months after the stroke. ANCOVA analyses adjusting for baseline cognition/premorbid intelligence, vascular risk factors, age, sex and total baseline WMH volume found that the recent small subcortical infarcts (RSSI) in the internal/external capsule/lentiform nucleus and centrum semiovale did not predict cognitive scores at 12 and 36 months. However, RSSI location moderated voxel-based associations of WMH change from baseline to 1 year with cognitive scores at 1 and 3 years. WMH increase in the external capsule, intersection between the anterior limb of the internal and external capsules, and optical radiation, was associated with worsening of ACE-R scores 1 and 3 years post-stroke after accounting for the location of the index infarct, age and baseline cognition.

Stability of Estimated Premorbid Cognitive Ability over Time after Minor Stroke and Its Relationship with Post-Stroke Cognitive Ability

Considering premorbid or “peak” adult intelligence (IQ) is important when examining post-stroke cognition. The stability of estimated premorbid IQ and its relationship to current cognitive ability in stroke is unknown. We investigated changes in estimated premorbid IQ and current cognitive ability up to three years post-stroke. Minor stroke patients (NIHSS < 8) were assessed at one to three months, one and three years’ post-stroke. The National Adult Reading Test (NART) and Addenbrooke’s Cognitive Examination-Revised (ACE-R) were used to estimate premorbid IQ (NART IQ) and current cognitive ability respectively at each time-point. Baseline demographics, vascular and stroke characteristics were included. Of the 264 patients recruited (mean age 66), 158 (60%), 151 (57%), and 153 (58%) completed cognitive testing at each time-point respectively. NART IQ initially increased (mean difference (MD) = 1.32, 95% CI = 0.54 to 2.13, p < 0.001) before decreasing (MD = −4.269, 95% CI = −5.12 to −3.41, p < 0.001). ACE-R scores initially remained stable (MD = 0.29, 95% CI = −0.49 to 1.07, p > 0.05) before decreasing (MD = −1.05, 95% CI = −2.08 to −0.01, p < 0.05). Adjusting for baseline variables did not change the relationship between NART IQ and ACE-R with time. Increases in NART IQ were associated with more education. For ACE-R, older age was associated with declines, and higher NART IQ and more education was associated with increases. Across 3 years, we observed fluctuations in estimated premorbid IQ and minor changes in current cognitive ability. Future research should aim to identify variables associated with these changes. However, studies of post-stroke cognition should account for premorbid IQ.

The impact of early-life intelligence quotient on post stroke cognitive impairment

Background Cognitive impairment can complicate minor stroke, but there is limited information on risk factors including peak cognitive ability earlier in life. Methods We recruited patients with clinically-evident lacunar or minor non-lacunar ischaemic stroke, recorded clinical features, vascular risk factors, magnetic resonance imaging-detected stroke sub-type and small vessel disease burden. At 1–3 and 12 months after stroke, we assessed educational attainment (years of education), current cognition (Addenbrooke’s Cognitive Examination–Revised), pre-morbid intelligence (National Adult Reading Test) and dependency (modified Rankin Scale). Results We recruited 157 patients (87 lacunar, 64 non-lacunar ischaemic strokes), median age 66 (inter-quartile range 56–74) years, 36/157 (23%) patients had a Addenbrooke’s Cognitive Examination–Revised score < 82 at one to three months, 29/151 (19%) had a Addenbrooke’s Cognitive Examination–Revised < 82 at one year. Lower National Adult Reading Test score (cognitive impairment per point on National Adult Reading Test odds ratio 0.91, 95% confidence interval 0.87, 0.95) and older age (per year of age odds ratio 1.04 (95% confidence interval 1.01, 1.08) predicted one-year cognitive impairment more than stroke severity (per point on National Institute of Health Stroke Scale odds ratio 0.96 (95% confidence interval 0.0.68, 1.31)) or vascular risk factors e.g. hypertension (odds ratio for diagnosis of hypertension 0.52 (95% confidence interval 0.24, 1.15). Cognitive impairment was associated with having more white matter hyper-intensities (odds ratio per point increase in Fazekas score 1.42, 95% confidence interval 1.11, 1.83). Discussion This observational study provides evidence that pre-morbid intelligence quotient and education predict cognition after stroke, and confirms the association between cognitive impairment and small vessel disease. Conclusion Pre-morbid intelligence should be considered in future studies of post-stroke cognition.

Depression is associated with lower American National Adult Reading Test scores among rural dwellers aged between 50 and 64 years in Texas: A Project FRONTIER Study

Background: Previous studies have shown that depression is associated with cognitiveimpairment. However, others have shown that there is no significant difference in the scoresof the National Adult Reading Test (NART), a screening test for intellectual functioning andgeneral level of education, between those with vs. without depression. This study sought toexamine whether depression is associated with the American version of NART (AMNART) ina rural cohort of West Texas.Methods: Participants with IQ and AMNART tests were selected from Project FRONTIER,an ongoing epidemiology study of rural residents in four West Texas counties.Results: AMNART scores were significantly lower in participants with depression(23.3±9.2) vs. those without depression (25.9±9.9) (p<0.05). Analysis by age group showedthat AMNART scores were significantly lower in those with depression (22.0±10.1) comparedwith those without depression (26.2±10.2) in the age group 50 to 64 years (P=0.0322). AlthoughAMNART scores were lower in participants with depression than those without depression inthe age groups 40 to 49 years (25.0±8.6 vs. 26.2±10.2) and 65 years or older (23.6±8.2 vs.25.6±9.5), they were not statistically significantly different.Conclusions: Depression is associated with lower AMNART scores in rural residentsaged between 50 and 64 years in West Texas.