Does stroke laterality predict major depression and cognitive impairment after stroke? Two-year prospective evaluation in the EMMA study.

Depression and cognitive impairment are common conditions following stroke. We aimed to evaluate stroke laterality as predictor of post-stroke depression (PSD) and cognitive impairment (PCI) in a stroke cohort. Major depression (Patient Health Questionnaire-9, score ≥ 10) and cognitive impairment (Modified Telephone Interview for Cognitive Status, score < 14) were evaluated at 6 months and yearly up to 2 years. Survival analyses were performed by Kaplan-Meier curves and Cox logistic regression models, adjusted for potential confounders (cumulative hazard ratio, HR; 95% confidence interval, CI), for the likelihood of subsequent PSD or PCI progression at 6 months and 2 years, according to stroke laterality (right hemisphere-reference). Among 100 stroke patients, we found 19% had PSD and 38% had PCI 2 years after stroke. Most participants (53%) presented right-sided stroke. However, right-sided stroke was not associated with PSD or PCI. Overall, left-sided stroke was an independent and long-term predictor of PCI, but not of major depression. Left-sided stroke was associated with a high probability of PCI (42.6% and 53.2%, respectively at 6 months and 2 years, p-log-rank: 0.002). The HR of PCI due to left-sided stroke was 3.25 (95%CI, 1.30-8.12) at 6 months and remained almost the same at 2 years (HR,3.22;95%CI, 1.43-7.28). The risk of having worse cognition status increased by >3 times, 2 years after stroke. The results support the hypothesis that involvement of networks in the left, but not in the right hemisphere, contribute to long-term cognitive impairment. Lesion laterality did not influence the risk of PSD.