Topography of acute stroke in a sample of 439 right brain damaged patients

Abstract

Knowledge of the typical lesion topography and volumetry is important for clinical stroke diagnosis as well as for anatomo-behavioral lesion mapping analyses. Here we used modern lesion analysis techniques to examine the naturally occurring lesion patterns caused by ischemic and by hemorrhagic infarcts in a large, representative acute stroke patient sample. Acute MR and CT imaging of 439 consecutively admitted right-hemispheric stroke patients from a well-defined catchment area suffering from ischemia (n = 367) or hemorrhage (n = 72) were normalized and mapped in reference to stereotaxic anatomical atlases. For ischemic infarcts, highest frequencies of stroke were observed in the insula, putamen, operculum and superior temporal cortex, as well as the inferior and superior occipito-frontal fascicles, superior longitudinal fascicle, uncinate fascicle, and the acoustic radiation. The maximum overlay of hemorrhages was located more posteriorly and more medially, involving posterior areas of the insula, Heschl's gyrus, and putamen. Lesion size was largest in frontal and anterior areas and lowest in subcortical and posterior areas. The large and unbiased sample of stroke patients used in the present study accumulated the different sub-patterns to identify the global topographic and volumetric pattern of right hemisphere stroke in humans.

Keywords: Hemorrhage; Infarct; Lesion mapping; Lesion size; Volumetry.

Fig. 1

Simple overlay plots for (A) all 439 acute right brain damaged patients, (B) for infarcts only (n = 367), (C) for hemorrhages only (n = 72), and (D) a 3D-rendered overlay plot for all 439 acute right brain damaged patients.

Fig. 2

Lesion size topographies in cm² for each voxel lesioned in at least five patients for (A) all 439 acute right brain damaged patients, (B) for infarcts only (n = 367), and (C) for hemorrhages only (n = 72), each scaled to show the complete possible range from zero to maximal average lesion size. Panel (D) shows average lesion size for all 439 acute right brain damaged patients (same data as in panel A), but with the color-coding rescaled to more effectively visualize variation that is not visible with the color-coding in panel A, especially the variability of lesion size within the territory of the MCA.