Abstract T P75: Vertex Analysis Demonstrates Significant Changes in Contralesional Thalamus 3 Months After Ischemic Stroke
Objective: Changes in remote brain structures after stroke may correlate with functional outcomes. We sought to investigate contralesional subcortical structural change after stroke.
Methods: 15 patients with carotid territory ischemic stroke underwent 3T MRI within 7 days of onset and at 3 months. Imaging involved a 1mm T1 axial MPRAGE. In 6 patients with left hemispheric stroke, scans were inverted across the midline to allow group comparison. FIRST (Part of FSL) was used to segment subcortical structures including thalamus, pallidum, caudate, putamen, hippocampus, accumbens and brainstem. Analysis was restricted to the non-stroke hemisphere due to the confounding effect of stroke lesions and edema in the lesional hemisphere. Change in volume was assessed as percentage change between the time points. A vertex analysis was performed in order to also identify areas of significant surface atrophy. Briefly, a surface mesh is created for each structure at each time point. Vertex wise statistical analysis then allows for the identifications of areas of significant surface atrophy between baseline and follow-up within the group.
Results: Mean age was 71y. Median baseline NIHSS was 9. Vertex analysis demonstrated atrophy over the superior and inferior surface of the contralesional thalamus between baseline and 3 months (figure, p<0.05 multiple comparisons corrected). The median overall change in contralesional thalamic volume was -0.96% (IQR -0.11 - -1.98%), but this difference was not statistically significant (p=0.1). No statistically significant changes in other subcortical structures were found.
Contralesional thalamus (blue) superior (A) and inferior (B) views with areas of significant atrophy (red)
Conclusions: We have described post stroke surface changes in the contralesional thalamus. This may be a result of deafferentation occurring during the recovery phase. An analysis in a larger number of patients may allow correlation with clinical endpoints.
Author Disclosures: N. Yassi: None. B.C.V. Campbell: None. A. Bivard: None. C. Malpas: None. M.W. Parsons: None. P.M. Desmond: None. S.M. Davis: Honoraria; Modest; Lectures sponsored by Boehringer Ingelheim, Covidien, Pfizer, Siemens. Consultant/Advisory Board; Modest; Boehringer Ingelheim.
- © 2015 by American Heart Association, Inc.