PMC

Comparison of distinct neuropil volumes in female and male hemispheres. (A) Volumes of 8 selected neuropils from both hemispheres in the representative male brain. (B) Volume ratios of these neuropils. The dashed line illustrates the hemispheric ratio threshold (T), computed from the hemispheric ratio in the representative brain at a 10% significance level. (C) Volumes of 8 selected neuropils from the female and male hemispheres in the bilateral gynandromorphic brain. (D) Hemispheric ratios of these structures. The dashed line illustrates the same kind of threshold (T) as shown in panel B. Columns in yellow show the 3 neuropils exceeding the threshold (T). (E) Comparison of the presumed hemispheric ratio (= 0, grey dash line) and the actual hemispheric ratio in the gynandromorphic and the representative brain, respectively. (F) Hierarchical clustering based on the hemispheric ratio of 16 neuropil pairs from the representative brain (indicated by R) and the gynandromorphic brain (indicated by G), including 8 left vs. right hemispheric neuropil pairs and 8 male vs. female hemispheric neuropil pairs (N = 16). Each neuropil was color-coded by the value of its hemispheric ratios. (G,H) 3D reconstructions of the 8 neuropiles in both brains. The neuropils having higher hemispheric ratios than the threshold (T) are marked in yellow. *, one-sample t test, compared with the hemispheric ratio in a theoretically symmetrical brain (0%), p < 0.05.

Suppose that μ_ipsi and μ_contra are true value of index I in ipsilateral and contralateral sides to epileptogenicity and ΔI = I_right − I_left is the hemispheric variation (depicted by stars). The 95% CI of μ_contra − μ_ipsi was calculated as (ΔI − HVU_U, ΔI + HVU_U) for ΔI as the hemispheric variation of FA within the fornix crus (depicted between minuses), FA within the posteroinferior cingulum (depicted between triangles facing inward), the hemispheric variation of hippocampal MD (triangles facing outward), the hemispheric variation for hippocampal volumetrics (between squares), and the hemispheric variation for hippocampal FLAIR signal intensities (between circles). An individual patient was considered to have a true hemispheric variation if the 95% CI of the true hemispheric variation did not contain zero.
Note that the Patients# 1 to 10 belong to TLE patients with pathology proven MTS.

Relationships between left and right hemispheric activation. A. Brain renderings show the ROIs corresponding to the left hemispheric CSN (LH CSN), right hemispheric CSN (RH CSN), mirrored left hemispheric CSN (Mirror LH CSN), and out‐of‐network left hemispheric homologues (OON‐LH‐Hom). B. Scatterplots illustrating the relationship between residual (with the effects of lesion volume partialled out) SD‐driven activity in the LH CSN ROI (y‐axes) and each right hemispheric ROI (x‐axes) are shown for the stroke group (top). Scatterplots illustrating the relationship between SD‐driven activity in the LH CSN ROI (y‐axes) and each right hemispheric ROI (x‐axes) are also shown for the control group (bottom). C. Line plots illustrate relative activation magnitudes in the LH CSN ROI and each right hemispheric ROI for the stroke (left, red) and control (middle, blue) groups. Means and standard errors of activation magnitudes at each ROI are also shown for both groups (right). D. Scatterplots illustrate the relationships between left hemispheric lesion volume and activity in each ROI. Note: Units for activation magnitudes correspond to contrast estimates. Units for lesion volume correspond to percentages of the maximum lesion volume. [Color figure can be viewed at http://wileyonlinelibrary.com]

Summary of results: Hemispheric dominance as determined by fTCD and fMRI. The latter was determined using three different methods (LI_ext.anat, LI_ext.func, LI_mag.func). In all but three subjects, hemispheric dominance could be determined unambiguously by both methods. In the remaining three cases, fMRT data indicated an ambiguous hemispheric dominance. As discussed in the text, fTCD and fMRT nevertheless provide concordant information about hemispheric dominance for spatial attention.