Abstract DP070: Ipsi-lesional Thalamus Atrophy after Stroke Predicts Functional Outcomes

The thalamus serves as the brain's relay station, processing information and facilitating communication between almost all regions of the nervous system. In our previous cross-sectional study focused on the chronic stages of stroke, we identified key demographic factors contributing to the decrease in thalamus volume, such as age and intracortical volume. We have built on these findings by analyzing a longitudinal imaging dataset that tracks stroke patients from the acute to chronic stages. This longitudinal dataset not only confirms our previous findings but also demonstrates a correlation between the volume of the ipsilesional thalamus and motor function over time. After conducting quality control, we analyzed T1-weighted and T2-weighted MRI scans from 62 stroke patients, each with three time points: 2 weeks (A), 3 months (C), and 12 months (C2) following their stroke. The data were processed using Freesurfer’s longitudinal pipeline, and thalamic segmentation was refined with Freesurfer’s Iglesias thalamic nuclei segmentation. We modeled thalamus volume using ANOVA in JMP Pro 17, incorporating factors such as 'time since stroke,' 'lesion volume,' 'age,' 'intracranial volume,' and 'gender' to explain the observed decrease in thalamus volume. Motor function was assessed using Motricity Index scores, and the correlation between thalamus volume and motor function was analyzed with a mixed model approach in JMP Pro 17. All statistical results are presented with F or t values and their associated p-values. Our findings indicate that the ipsilesional thalamus decreases over time, whereas the contralesional thalamus remains unchanged. Significant covariates affecting the change in ipsilesional thalamus volume include estimated intracranial volume, lesion volume, time since stroke, and the interaction of age with lesion volume. Additionally, we confirm a significant correlation between ipsilesional thalamus volume and motor function across the three time points. Patients with a greater preserved LK1 ipsilesional thalamus volume tend to have better motor function outcomes. After a stroke, the ipsilesional thalamus shrinks while the contralesional thalamus remains stable. An interaction between age and disease severity was observed, suggesting the thalamus could be a biomarker for assessing stroke impact on motor function. Understanding aging's relationship with disease can help personalize treatment and rehabilitation to improve outcomes and reduce disabilities.